Diversity creation methods A survey and categorisation
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高一英语学术研究方法单选题40题1. What is a research hypothesis?A. A statement that is always true.B. A prediction about the relationship between variables.C. A conclusion based on research findings.D. A question that needs to be answered.答案:B。
选项A,研究假设不是总是正确的陈述。
选项C,研究假设是在研究之前做出的预测,不是基于研究发现的结论。
选项D,研究假设不是一个需要回答的问题,而是对变量之间关系的预测。
2. What is a literature review?A. A summary of all the books on a topic.B. A critical analysis of existing research on a topic.C. A collection of research papers.D. A list of research questions.答案:B。
选项A,文献综述不仅仅是对一个主题的所有书籍的总结。
选项C,文献综述不是简单的研究论文集合。
选项D,文献综述不是研究问题列表。
3. What is a research method?A. A way to collect data.B. A theory about a topic.C. A conclusion from research.D. A list of research questions.答案:A。
选项B,研究方法不是关于一个主题的理论。
选项C,研究方法不是研究得出的结论。
选项D,研究方法不是研究问题列表。
4. What is a sample in research?A. A part of the population being studied.B. The entire population.C. A list of research questions.D. A research method.答案:A。
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文档下载后可定制随意修改,请根据实际需要进行相应的调整和使用,谢谢!并且,本店铺为大家提供各种各样类型的实用资料,如教育随笔、日记赏析、句子摘抄、古诗大全、经典美文、话题作文、工作总结、词语解析、文案摘录、其他资料等等,如想了解不同资料格式和写法,敬请关注!Download tips: This document is carefully compiled by theeditor. I hope that after you download them,they can help yousolve practical problems. The document can be customized andmodified after downloading,please adjust and use it according toactual needs, thank you!In addition, our shop provides you with various types ofpractical materials,such as educational essays, diaryappreciation,sentence excerpts,ancient poems,classic articles,topic composition,work summary,word parsing,copyexcerpts,other materials and so on,want to know different data formats andwriting methods,please pay attention!I recently conducted a survey on people's eating habits, and the results were quite interesting. One person mentioned that they always start their day with a cup of coffee, claiming that it gives them the energy they need to kickstart their morning. Another participant, on the other hand, admitted to skipping breakfast altogether, statingthat they simply don't have the time or appetite for it.It's fascinating to see the wide range of breakfast preferences people have.When it comes to lunch, there seems to be a divide between those who prefer homemade meals and those who optfor convenience. Some individuals enjoy the process of preparing their own lunches, finding it therapeutic and satisfying. They take pride in knowing exactly what goesinto their food. On the flip side, others find it more convenient to grab a quick bite from a nearby restaurant or order takeout. They value the time saved and the variety of options available to them.Dinner, for many, is a time to unwind and enjoy a fulfilling meal. Some participants mentioned that they love experimenting with new recipes and flavors, often tryingout different cuisines from around the world. They find joy in the process of cooking and view it as a creative outlet. On the contrary, some individuals admitted to relyingheavily on frozen or pre-packaged meals for dinner. They prioritize convenience and ease of preparation overculinary exploration.Snacking habits also varied greatly among the survey participants. Some individuals confessed to having a sweet tooth, indulging in chocolates, cookies, and other sugary treats throughout the day. They find comfort and pleasurein these little moments of indulgence. Others, however, opt for healthier snack options such as fruits, nuts, or yogurt. They prioritize nourishing their bodies and maintaining a balanced diet.Lastly, the survey touched upon people's preferencesfor dining out. Many participants expressed their love fortrying new restaurants and exploring different culinary experiences. They enjoy the social aspect of dining out and the opportunity to discover new flavors. On the other hand, some individuals mentioned that they prefer cooking at home and hosting dinner parties. They find joy in creating a warm and inviting atmosphere for friends and family.In conclusion, this survey highlighted the diversity in people's eating habits and preferences. From breakfast routines to dining out choices, everyone has their own unique approach to food. It's fascinating to see how our individual tastes and lifestyles shape our relationship with what we eat.。
2022-2023学年江苏省镇江市九年级上学期期末英语试题1. My family watched________one﹣hour documentary showing at Sunshine Cinema.A.an B.the C.a D./2. Former president,Jiang Zemin,passed away peacefully________30th November,2022.A.in B.under C.at D.on3. Don’t always give orders to your child,follow his interests________.Then,you can understand him better.A.closely B.widely C.highly D.easily4. —John is not coming for the birthday party tonight.—Why? But he ________!A.promises B.promised C.will promise D.is promised5. If you want to work out the problem of stress, you need to find out the ________ first.A.method B.cause C.thought D.suggestion6. The book the Adventures of Tom Sawyer is________interesting that I’ve read it twice.A.too B.such C.very D.so7. Many tourists are __________by the beautiful view here every year.A.attracted B.arrested C.attacked D.accepted8. — How fast Nantong is developing!—Exactly. It’s such a ________ city that everyone enjoys life here.A.living B.alive C.lively D.live9. The game between Germany and Japan in the 2022 World Cup________to be more exciting and surprising than we had thought.A.put out B.took outC.turned out D.stayed out10. My sister is a/an ______ girl and she can practice dancing for hours without having a rest.A.energetic B.modest C.confident D.curious11. 【2017·江苏苏州· 7】—I'm afraid I can't come to your wedding,Julia.—________! But why?A.How happy B.How lucky C.What a pity D.What nice news12. President Xi reported that our party has led people in solving________problems over the past five years.A.the number of B.a number ofC.a deal of D.a great deal13. Who can help me find the information about the singer ________ I need to give a talk?A.whom B.who C.what D.which14. If you don’t go hiking this Sunday, ________.A.so will I B.so do I C.neither will I D.neither do I 15. If the little boy________to keep away from power,he will be in danger.A.isn’t told B.won’t be toldC.doesn’t tell D.won’t tell16. The party tonight________the end of our summer vacation.Tomorrow we’ll go back to school.A.changes B.marks C.creates D.doubts17. 一Hello, Helen! Can I see Mr. Smith?一 . I'll tell him you are here.A. Never mind B. It sounds like funC. Just a minute D. Sorry to hear that18. —When will the rain stop?—________ next Thursday. The weather report says it will last for a week.A.Until B.Before C.After D.Not until19. The Shape of Water was a big winner at the 90th Academy Awards, winning four Oscars: Best Production Design, Best Score, Best Director and Best Picture.A. as soon as B. as well as C. as much as D. as good as 20. Could you please tell me________?A.whom we can ask for helpB.that I should go to the right doorC.where have you beenD.who was the woman in whiteSpanish painter Pablo Picasso was a leader in Western art in the 20th century.No painter before him had enjoyed such a ________number of followers in his own lifetime.Born on Oct 25,1881,Picasso had ________more than 20,000 paintings,drawings,sculptures and other pieces of art by the time he died at 91.That’s a long time to paint!People often list eight different ________in the course of his painting career.Over a century ago,he once said,“Every act of creation is first of all an act of destruction(破坏).” So the eight periods are all very ________in their choice of subjects and yet unmistakably drawn by Picasso’s hands.As his style ________over time,it became more minimalist (极简风格的).A common joke is that Picasso forgot how to paint. ________,he was classically trained at the School of Fine Arts in Barcelona.Now he is best known for ________an artistic movement known as “Cubism (立体主义)”.It used shapes to create human and animal figures.With this ________,Picasso tried to show his figures from multiple perspectives(多维视角) in 2 D space.For example,a person’s left eye may be shown from straight ahead while his right eye and nose are shown from the side.The result is ________and beautiful,frightening and funny.Picasso often said that he admired the drawings made by children. “When I was their age,I could draw like Raphael,but it took me a lifetime to learn to draw like them (children),” he said.Maybe that’s ________Picasso is still so popular.We look at his work and think,“Maybe I could do that!”21.A.small B.large C.low D.high22.A.written B.composed C.created D.connected23.A.periods B.kinds C.times D.styles24.A.exciting B.relaxing C.interesting D.different25.A.began B.changed C.grew D.shone26.A.After all B.Above all C.In all D.At all27.A.fixing B.dividing C.leading D.guarding28.A.help B.dream C.connection D.method29.A.strange B.natural C.common D.simple30.A.how B.why C.when D.whereThere are many rules for us Chinese to follow to be better people and live better. “Do unto others as you would have them do unto you”,which is from The Analects of Confucius(《论语》),is worth our lifetime to practice.Chang Sheng,a Chinese teacher,explains the rule to us.It means that if you don’t want others to do something to you,then don’t do it to them.Put simply,avoid doing something to people that even you can’t tolerate(忍受) .It encourages us to put ourselves in others’ place,which will help us get along better.Confucius asked his students to follow and practice this rule their whole lives.This rule works well from ancient to modern times.It can be used in daily life.For example,if you don’t want others to talk about you behind your back,then don’t talk about others behind theirs.Another example is how to get along in group work.If you are a leader who is responsible for the tasks,you should consider,each member’s feelings and advantages to make the best decision instead of being bossy.China has been practicing this rule in all fields.President Xi Jinping used it many times in his speeches.He said China would respect other countries in cultural exchanges and always pursue peace.31. Which of the following may be the meaning of the underlined something in Paragraph 2?A.Personal taste.B.Personal information.C.Personal safety.D.Personal attack.32. According to the article,which of the following is NOT right?A.The rule is well worth practicing the whole lifeB.Confucius’s students were asked to follow the ruleC.The rule worked in ancient time but not in modern timeD.The rule is suitable for relationships between countries as well33. The rule “Do unto others as you would have them do unto you” is helpful for you ________.A.to get along with othersB.to make a quick decisionC.to tolerate everything in lifeD.to talk about others behind themStand in front of a mirror and look at it.How much do you really know about the person in it?It’s not easy to know ourselves.To help students,schools across China are providing more classes and activities on self﹣knowledge.Liu Yue,a teacher from Chengdu Yucai Middle School,has recently given her students a useful tool. “It’s called the Johari Window,developed by two US psychologists,” said Liu,“It has four areas a bout one’s self:open area(that everyone knows about),hidden area (that only you know),blind spot (that everyone knows except you) and unknown area(that nobody knows).Using this tool,students successfully saw themselves in a new way.”I’m most curious about my blind spot,“ said eighth﹣grader Yang Manfei. ”So I did asurvey.“ The results showed that Yang easily gets worried and impatient because of procrastination(拖延症). ”That’s a bad habit“ Yang said.”I find the unknown area more amazing,“ said Sun Boyin. ”I t means everyone has lots of potential.“ He wasn’t good at math at first. ”But I set a goal and did many math exercises.Now I’m much better at math.The unknown part of my math ability is getting clearer!“ Sun said.When it came to ________,most students ke pt silent. ”I’m scared to show my secrets deep down,“ said Li Yixuan ”Then one classmate stood up and said his favourite cartoon is Tom and Jerry.I thought:am I brave enough to show my childish hobby?Perhaps not.I want my classmates to see me as a grown﹣up,not a kid.But then I realized that I don’t find that classmate silly.I think he has the power to be himself.“”Show yourself and make yourself better―that’s the best lesson I learned,“ Li said.34. Which of the following can be put into”________“in Paragr aph 6?A.the open areaB.the hidden areaC.the blind spotD.the unknown area35. What did Li yixuan learn from the test?A.Everyone has a part of that is childish.B.You have the right to keep your secrets hidden.C.People prefer to be grown﹣ups in front of others.D.Showing your true self helps you improve yourself.36. What is the purpose of this article?A.To tell the importance of knowing yourself.B.To introduce a method of knowing yourself.C.To tell the stories of students knowing themselves.D.To introduce the specific knowledge about your potential.William Banting was born in 1797 in London.Thanks to the success of his family’s business,he was able to lead a comfortable life.By his mid﹣thirties,Banting had been struggling with his weight.Banting wanted to lose weight.His doctor suggested that he should do more physical exercise.Every morning,Banting rowed on the Thames.Although he did exercise more,he also ate more.Banting also tried steam baths,but this had little effect on his weight.By the time he reached his middle age,the fat man had started having trouble tying his shoelaces(鞋带).Just as things seemed hopeless,Banting’s doctor went on holiday.In his absence,Banting booked an appointment(预约) with another doctor in London.This doctor,Dr William Harvey,turned out to be able to save Banting.Dr Harvey put what he had just learned into practice.He suggested Banting should eat less food,like bread,butter,sugar,potatoes,etc.Breakfast was now beef with a small biscuit.Lunch was fish with vegetables.He also drank without sweet but some fruit.And dinner was made up of a piece of meat or some fish.Surprisingly Banting felt the effects of the diet almost immediately.At his heaviest,165﹣cm﹣tall Banting weighed 92 kg.Within a year,he had lost 17 kg.Banting wanted everyone to know how successful his diet had been.He published a book about his experiences.The book soon became popular all around the world.Banting continued to follow Dr Harvey’s advice for the rest of his life.He died in 1878,but his story of weight loss lives on.Today,”bant“ has become a verb.It means ”to watch what you eat“.37. How old was Banting when he died?A.35 B.47 C.78 D.8138. What made Banting lose weight successfully?A.Doing more exerciseB.Eating more vegetablesC.Eating suitable foodD.Making more friends39. Why did Banting publish a book about his experiences?A.He wanted to be famous all around the world.B.He wanted his doctor to be known by everyone.C.He wanted everyone to know his success in diet.D.He wanted to be wealthier from then on.40. What’s the best title of the article?A.A Successful BusinessmanB.A Successful WriterC.A Successful DoctorD.A Successful Man in Diet41. What the parents did has ________([ˈɪnfluənst]) the child a lot.42. A famous painting was ________(steal) in an art museum yesterday.43. He searched everywhere for the mask because it has gone ________(miss).44. It’s really ________(pleasant) to see dust everywhere again after cleaning the house for 3 ho urs.45. ________(Asia) football players gave their best performance in this year’s World Cup.46. The salesman kept ________(contact) the customers till all the problems were solved.47. The poor boy fell and landed ________(heavy) at the bottom of the stairs.48. The bad weather ________(force) them to work outside last week.49. Professor Wu has ________(从事)teaching physics for at least 40 years.50. No one will believe in a person who has ________(说谎) many times to others.51. With excellent music and lyrics,the new song has ________(成功) hit the heart of everyone.52. Some ________(产业) are making more use of computers to control their production.53. Since last week,no clues have been ________(报告)to the police.54. —Why is he so angry?—He has been at the desk for 2 hours without writing down a ________(单个)word.55. We ________(取消) the visit to Washington yesterday because of the awful weather.短文填空What will astronauts eat when a space trip takes years?”Lots of fresh vegetables,“ says Dr.Janet Williams,whose team have spent the last 10 years learning h 56 to grow plants in a space station.And it’s a good thing that she has already started her work.As u 57 ,astronaut George White looked into the closed plant room.He had planted Dr.Williams’s quick﹣growing seedlings(幼苗) in it,but none of the stems(茎) was showing.He opened the room to check and found the p 58 .The roots(根) weren’t growing downwards and the stems weren’t growing upwards.On Earth,gravity h elps a plant’s stems and roots to find ”up“ and ”down“.H 59 ,there was almost no gravity in the space station.Dr.Williams advised to give the plants more light,as plants also use sunlight to find their way.And i 60 worked.Then Dr.Williams was worried about the n 61 problem:Can we grow food on a space journey?Many plants died in the space station.Dr.Williams thought she knew w 62 the space plants were hungry for air.Plants live by taking up CO2 from the air.Since a plant uses it up in the air a 63 ,the plant needs moving air to bring more CO2 c 64 to its surface!Dr.Williams tried a new greenhouse that had a fan to keep the air moving.The plants loved it.They flowered and e 65 produced more seeds. ”And this,“ says Dr.Williams,”is good news for long﹣term space travel.“Every day,we open and close doors with nothing special happening.But that’s different for Suzume in the film Suzume no Tojimari (铃芽的门锁).One day,the 17﹣year﹣old girl met a boy and followed him to find a door in some ruins(废墟) .After she opened the door,she found a secret!The door connects to a world full of those who have died in earthquakes,and opening the door brings disasters.As doors began to open one after another in Japan,Suzume starts her journey of door﹣locking.As a typical work of Japanese director Makoto Shinkai,the film continues the topic of ”love“ and ”missing“,when Suzume tries to see her mother who died in an earthquake from the other side of the door.But what makes the movie stand out is that instead of personal experiences like friendship or romance,it makes humans think of the common memory of disaster and hope.After the long﹣period of sadness of her mother’s death,Suzume begins to be reconciled(和解) with herself as she realizes that other people have moved on.This may also be what the director Shinkai wants to tell people around the world:All will be fine in the end no matter how difficult and challenging the situation is.We are supposed to look forward to a better future.Just as Suzume told her younger self,”I never l ost anything and the future is never fearful.“阅读以上信息,用恰当的单词完成下面的短文,每空一词。
高二英语科技成果单选题50题(带答案)1.The development of technology has brought many____changes to our lives.A.significantB.insignificantC.occasionalD.rare答案:A。
本题考查形容词辨析。
“significant”表示重大的、显著的;“insignificant”表示不重要的;“occasional”表示偶尔的;“rare”表示罕见的。
科技的发展给我们的生活带来了很多重大的变化,所以选A。
2.Modern technology has created____tools for communication.A.efficientB.inefficientC.limitedeless答案:A。
“efficient”表示高效的;“inefficient”表示低效的;“limited”表示有限的;“useless”表示无用的。
现代科技创造了高效的通讯工具,所以选A。
3.The new scientific discovery is of____importance.A.greatB.littleC.someD.no答案:A。
本题考查固定搭配。
“of great importance”表示非常重要。
新的科学发现非常重要,所以选A。
4.Technological advances have led to____improvements in healthcare.A.dramaticB.slightC.noD.rare答案:A。
“dramatic”表示巨大的、戏剧性的;“slight”表示轻微的;“no”表示没有;“rare”表示罕见的。
科技进步给医疗保健带来了巨大的改善,所以选A。
5.The latest technology product is____in design.A.advancedB.backwardC.old-fashionedD.outdated答案:A。
爱好调查作文英语Introduction:Hobbies are a significant part of our lives, providing us with relaxation, joy, and a sense of accomplishment. They can also be a window into our personalities and preferences. In this essay, I will present the results of a survey conducted to understand the hobbies of a diverse group of individuals.Methods:The survey was distributed both online and in-person to a random sample of 200 people, ranging from teenagers to senior citizens. Participants were asked to list their top three hobbies and provide a brief explanation of why they enjoy these activities.Results:1. Reading: Notably, reading emerged as the most popular hobby across all age groups. Many respondents cited the love for stories, the opportunity to learn new things, and the ability to escape into different worlds as reasons for their passion for reading.2. Sports and Fitness: Engaging in sports or fitnessactivities was another common hobby. This category included a wide range of activities from team sports like soccer and basketball to individual pursuits such as running and yoga. The benefits of physical health and stress relief were frequently mentioned.3. Music and Dance: Music and dance were also popular, with many participants enjoying both the creation and appreciation of music. Playing an instrument, singing, and dancing wereall mentioned as hobbies that bring happiness and a sense of achievement.4. Travel and Exploration: A significant number of respondents listed travel as a hobby, with the desire to experience new cultures, cuisines, and landscapes being the primary motivations.5. Arts and Crafts: Creating art, whether it be painting, drawing, knitting, or woodworking, was another hobby that many found fulfilling and therapeutic.Discussion:The survey results indicate that people's hobbies are diverse and multifaceted, reflecting a range of interests and values. Reading and sports were the most common hobbies, suggesting a general appreciation for mental and physical well-being. The popularity of music and travel suggests a widespread desire for creative expression and cultural experiences.Conclusion:Hobbies play a crucial role in enhancing our quality of life by providing entertainment, personal growth, and social interaction. The survey has shown that while there are common interests among people, each individual's choice of hobbiesis unique and personal. Understanding these hobbies can help us appreciate the diversity of human interests and therichness of our collective experiences. Word Count: 350 words。
从…中挖出来的英文短语Unearthing Buried History: A Journey intoArchaeological Excavations.Across the globe, beneath layers of earth and time, lie the remnants of civilizations past. These buried treasures, frozen in a capsule of bygone eras, hold tantalizingsecrets that can rewrite our understanding of human history. Archaeological excavations, like skilled surgeons delving into the body of time, meticulously unearth these hidden fragments, providing us with a glimpse into the lives, cultures, and beliefs of our ancestors.Excavating the Past: A Step-by-Step Journey.1. Initial Survey:The first step towards an excavation is a thorough survey of the site. This involves studying maps, aerial photographs, and conducting geophysical surveys to identifyareas of potential archaeological significance.2. Excavation Planning:Once the site has been surveyed, a detailed excavation plan is formulated. This plan outlines the excavation strategy, including the excavation methods to be used and the safety protocols to be followed.3. Excavation Techniques:Archaeological excavations employ a range of techniques to carefully remove layers of earth and expose underlying features. These techniques include:Troweling: Delicately removing soil with a trowel to uncover delicate artifacts and structures.Scraping: Using a scraper to remove thin layers of soil, revealing buried surfaces and features.Sifting: Screening soil through meshes to recoversmall artifacts and ecofacts, such as animal bones or plant remains.4. Feature Identification and Documentation:As excavations progress, archaeologists identify and document archaeological features, such as building foundations, hearths, burials, and artifacts. These features provide clues to past activities and the layout of the site.5. Artifact Collection and Analysis:Artifacts, including pottery, tools, weapons, and jewelry, are meticulously collected and analyzed. These artifacts offer valuable insights into the technological prowess, artistic skills, and cultural practices of the people who once inhabited the site.6. Stratigraphic Analysis:Soil layers, known as strata, provide achronological record of the site's history. Archaeologists carefully analyze the stratigraphy to determine the sequence of events that occurred at the site and the relative ages of different features and artifacts.7. Interpretation and Reconstruction:Once the excavation is complete, archaeologists interpret their findings and reconstruct the history of the site. This involves synthesizing data from the excavation, artifact analysis, and historical research to create a narrative of the site's past.Unveiling the Secrets of Buried Civilizations.Archaeological excavations have unearthed countless treasures that have transformed our understanding of human history. Here are a few notable examples:Pompeii, Italy: The volcanic eruption of Mount Vesuvius in 79 AD preserved the Roman city of Pompeii under a thick layer of ash and pumice. Excavations have revealedremarkably preserved buildings, streets, and artifacts, providing an unparalleled glimpse into Roman life.Terracotta Army, China: Discovered near the tomb of the first emperor of China, Qin Shi Huang, the Terracotta Army consists of thousands of life-sized terracotta warriors and horses. This monumental ensemble is a testament to the artistic achievements and military prowess of ancient China.Nazca Lines, Peru: The Nazca Lines are a series of immense geoglyphs etched into the Peruvian desert. These intricate designs, visible only from the air, have puzzled archaeologists and inspired countless theories about their creation and purpose.The Value of Archaeological Excavations.Archaeological excavations are not mere treasure hunts. They are meticulous scientific investigations thatcontribute to our collective knowledge and understanding of human history. Excavations:Preserve Our Cultural Heritage:Archaeological sites and artifacts are irreplaceable pieces of our collective cultural heritage. Excavationshelp to protect and preserve these valuable resources for future generations.Provide Historical Insights:Excavations provide tangible evidence of past events, shedding light on the lives, cultures, and beliefs of our ancestors. They fill in the gaps in our historical record and help us to understand the human experience throughout time.Challenge Historical Narratives:Archaeological discoveries can sometimes challengeor overturn established historical narratives. Byuncovering new evidence and re-examining old assumptions, excavations can lead to a more complete and accurate understanding of the past.Inspire Future Generations:The wonders unearthed through archaeological excavations continue to inspire and fascinate people of all ages. Excavations ignite curiosity, foster a sense of wonder, and promote a deeper appreciation for our shared human story.Conclusion.Archaeological excavations are like time machines that transport us to the past. Through meticulous excavation techniques, archaeologists painstakingly unearth buried relics, unraveling the secrets of lost civilizations and enriching our understanding of human history. From the ruins of ancient cities to the intricate designs of prehistoric geoglyphs, archaeological excavations reveal the incredible diversity, ingenuity, and resilience of our human ancestors. As we continue to explore the depths of the earth, we can expect countless more discoveries thatwill further illuminate the tapestry of our shared human experience.。
The definition of creativityIn 1869, a British psychologist Golton works <<genetic and genius>> opens the part of the psychologist the correlation between genetic and genius research and discussion of human creativity.Guilford served as President of the American psychological association, 1950, in his inaugural speech creativity to advocate the importance of creativity, calling for educational world to strengthen the study of creativity.Since then creativity increasingly brought to the attention of the psychological educational world.On the definition of creativity, researchers tend to be due to the difference of research interest and research perspectives, but hold different opinion. Rhodes (1961) to collect the literatures of the definition of creativity, think about the definition of creativity involves 4 P.I.e., the creator (Person), created by the Process (Process), to create products (Product),Create the circumstances (Place).Although the Chinese and foreign scholars so far view of creativity is not unanimous, but most scholars in recent years are the Angle of "product" to define the judging standard of creativity.(Suchas:Guilford,1985;Stemberg&Lubart1985oldham&cummings,231;Amabile,1996;Mayer)(19 99)After finishing all the scholars on the definition of creativity, found that most of scholars agree creativity can observe from the point of view of the product (product), although scholars describe different words, but all think creative product should have two characteristics:(a) novelty: (will be) related words including new (new), creativity, originality and alone 'J (the original), etc.(2) the applicability (usefulness) : related words include valuable (valuable), appropriate (appropriate), important (significant), to adapt to the (adaptive) and practical (utility), etc.ZhanZhiYu (2002) extends Mayer (1999) analysis of the characteristics of a creative product, think this kind of classification is just an evolution of mutation and selection concept, thus to evolution's point of view of the two essential characteristics of creative products, one is the mutation of "novelty", "stand up to a selective pressure".In other words, the creative products must be innovative and valuable. Therefore, from the perspective of "product" creativity also can be simply defined as: ability to generate new and valuable products.Individual creativity and intrinsic motivationAmabile (1983) from the perspective of product ingredients of creativity theory put forward (the componential found ofcreativity) to describe the work environment affects the constituent elements of creativity, and further in 1996 to be revised and added the original composition pattern.Amabile (1983) argue that creativity is the field related skills (domain. The relevant skills), creativity, relevant skills (Chinese - relevant skills), work motivation, task motivation).During the course of creation, these three components are constantly interacting and affect the individual creativity, and the more the three intersections, had said the higher the individual's creativity. Amabile comprehensive previous research and creativity of three components, puts forward the creative component architecture diagram (componential framework of Chinese) to describe how these creative elements affect the course of creation of different steps.And the architecture in 1996 [1996 revised, joined thesocial environment influence on motivation, think social environmental factors affect the work motivation, in turn, affects the individual creativity.Stemberg&Lubart (1995) proposed "creativity investment theory" (investment going ofcreativity) will also be motivation as one of the six major resources required for creativity, think to will hide within the individual creativity potential out of there must be other auxiliary resources.The wisdom (intellectualabilities), knowledge (knowledge), thinking (styles oftllinking), personality (move), the motive (motivation) and environment (environment).Motivation can be explicit, such as money, power, fame; Can also be implicit, such as self expression, self challenge, both can inspire individuals, make its focus on the task at hand, but creative people the biggest motivation isimplicit.Sternberg&Lubart think the performance of the intrinsic motivation of creative special advantage, because only the intrinsic motivation of touches, can make a person will pay attention to what he is engaged in, and get fun from the process ofcreating.Steinberg & Lubart thought: in the process of idea generation, environmental factors play a very important role, because creativity is the product of a person and the environment interaction, some environment to encourage creativity, some environmental stifle creativity, thus including working atmosphere, leading factors such as creativity has become the influence of environmental variables.Csikszentmihalyi (1990) and Gardner (1990) on them about the developing mode of creative ability of individuals in the social environment, both the intrinsic motivation as an important personality causes creative achievements.Csikszentmihalyi think high levels of intrinsic motivation and relatively low levels of extrinsic motivation will make creative individual accompanying more independent in its activities, it is not easy to comply with the pressure.He also thinks problem determination is usually driven by strong interest and curiosity, solve the problem in the process of sticking driven by intrinsic reward experience when processing information.From the results of the theoretical study, the researchers are basically identical that internal motivation are beneficial to the individual creativity.In addition, many empirical studies also got consistent results with theoretical analysis:First of all, the internal motivation has a promoting effect on the performance of individual creativity. Because the internal motivation to promote individuals interested in activities and affect the activities of the investment.Second, the internal motivation to creative individual pursuit of challenging tasks.Again, the internal motivation to promote individual sustainability activities.All in all, both in theory and empirical results support that internal motivation is beneficial to the individual creativity. Instead the presence of extrinsic motivation will exert a negative effect on creativity(Amabile,1983).Individual creativity and mental authorizationPsychological authorization is a state of mind, it is the specific construction form of employees' intrinsic motivation, reflect the employee's perception of managers behavior and organizational environment, affected by direct leadership behavior(Conger,1989).Of enterprise management and organizational behavior at the early of authorized research focus in the superior subordinate authority granted, for subordinates to provide more information and resources, etc. In recent years, the research is more focused on the psychological level, is the focus of authorized itself to the spirit of the incentiveeffect.Canada McGill university professor Conger&Kanungo (1988) pointed out, such as authorized in a deep motivation connotation of self-efficacy, individual in the organization is to improve the dynamic process of self-efficacy authorization in essence not only is set for the external behavior of individual, it is also a kind of changing process of individual inner beliefs.Spritzer (1995) l think research authorization from the perspective of individual experience is more reasonable, because in the process of authorization, work is the individual's perception and experience, and not by the ACTS of the authorization.For psychological empowerment and individual innovative behavior in the organization, and some scholars studied the relationship between the abroad.Thomas (2000) argues that individual psychological empowerment and elasticity, so as to p romote innovative behavior. Kanter (995) study found, authorization, and innovationbehavior.Spreitzer (1 995), with the result of the empirical study shows that psychological authorization and innovation behavior were positively correlated, the authorization of the psychological level is higher, the higher the level of innovation behavior.Bell and Staw thought to have a stronger psychological authorized employees think their ability to do more meaningful work, and you can decide to work methods, working rhythm, and hard work.Thomas also think authorized employees pay more attention to the work, the more active and more cramped by inherent method to carry out their work.Therefore, authorized employees perceived leadership and organizational support for their creative work, will finish the work in their own way and not worry about their work without approval.Chinese scholars Liu Yaozhong (2008) in the psychological structure dimension of authorization and employee innovative behavior study of the relationship between the article using the empirical method is verified on the relationship between the two, the research suggests that psychological authorization and extremely significant correlation between individual innovation behavior, psychological authorization and individual creativity, stimulate the close relationship between, the psychological authorization level is higher, the individual innovation behavior, the more obvious, too.The main methodTo research on issues of paper and achieve expected purpose, this study will adopt the following methods:System research methods.System research method refers to the goal of a whole under the premise of using logic relationship analysis, correlation and interaction of the secondary system, in order to grasp things in complex and dynamic environment, a scientific method to solve the problem.This thesis of transformational leadership theory building, the relationship between transformational leadership and employee creativity, the relationship between transformational leadership and organization innovation ability has carried on the system analysis, as the research model and research hypothesis provides a theoretical basis is put forward.Survey statistical method.Survey statistical method is based on data from participants to answer the question to analysis and study the overall status of the research methods. The method mainly includes questionnaire and interview method.This topic addresses the issue of research on the basis of the reference maturity scale up and design the questionnaire, through individual interviews and large-scale sample survey, collect the survey data, the research discusses the regularity of the relationship between variables, and to answer the research question and hypothesis test.Data analysis methods.After made some sample data, this research use Spss and Amos software for data processing and analysis, using exploratory factor analysis and confirmatory factor analysis, correlation analysis and structural equation model analysis method to the corresponding conclusion and validation of hypothesis, the research propositions.Study design methods (research, the design method) is a process of research project structure and overall arrangement. The core of it is when we completed a study, the overall logic is clear, a research project of the relationship between the parts of the clear (Royer and Zarlowski, 2001).Design study, the researchers need to do is select the most appropriate for a particular research question research methods. The choice of research method in related disciplines under the guidance of the theory and methodology of the research process, the object of study on exploring the indispensable important segment.Discussed in detail in this chapter, this study intends to select the research methods and operating procedures, and summarizes the basic subjects.The structure of the questionnaireAccording to the study of the conception, comprehensive questionnaire the basic of this research include the following 2 parts:A leader questionnaire with employees. Leader questionnaire suitable for enterprise development manager and supervisor. Staff questionnaire is suitable for the enterprise research and development department staff members.(1)Questionnaire leader(2) employee questionnaireIn the process of the research ideas and research, this topic mainly follow the following basic technical route.Review and analysis of relevant theoriesLiterature review and analysisTransformational leadership and individual creativityTransformational leadership and organization innovation ability The determination of research model Questionnaire design and modification The questionnaire survey Data statistics and analysisThe research conclusion anddisadvantages and prospect(1) based on leadership theory, theory of individual creativity, innovation and innovation ability and other related theories and literature review and finishing, to determine the direction of this study.Also chose a few companies on an interview, the purpose is to correct selection of variables and from a practical point of view to establish research variables and the possibility of the architecture.(2) The theory discussed in this paper.On the basis of summarizing the predecessors' research results, from the transformational leadership and individual creativity, transformational leadership and organizational innovation Angle in-depth analysis and research on the relationship between the variables and research hypotheses are put forward.(3) Questionnaire design and prehensive comparison of Chinese and foreign scholars research results, based on the relatively mature scale, and combined with the purpose of this study, to define the conception of necessary amendment, measured by likert scale five scale related variables.In order to make the questionnaire to reflect the purpose of this study, in front of the questionnaire survey, first select two representative IT companies to interview and pilot test, and the combination of expert evaluation to modify questionnaire wording and options, in order to enhance the accuracy of the questionnaire data.(4) A formal large-scale questionnaire survey. Mainly in Shanghai, using electronic questionnaires, mailing and on-site survey sampling methods such as completed.(5) The empirical analysis and the results of discussion. The questionnaire of data statistics, validation and analysis. Conclusion the study comparing with the research achievements of predecessors.(6) Discuss the academic significance of the findings and Suggestions to the guidance of the enterprise management practice, points out limitations of this study and future research direction.。
观点加办法的英语作文Title: Embracing Diversity: A Key to Global HarmonyIn today's interconnected world, diversity is not just a reality; it is a strength that can lead to global harmony and progress. Embracing diversity means recognizing and respecting the unique qualities and contributions of individuals and cultures, rather than viewing them as obstacles or threats.Firstly, the importance of diversity cannot be overstated. It brings a richness of perspectives and ideas that can enhance innovation and creativity. When we have a diverse range of people working together, we are more likely to find solutions to complex problems and address challenges from multiple angles.However, embracing diversity is not without its challenges. Language barriers, cultural differences, and biases can create misunderstandings and conflicts. To overcome these, we need to foster an environment of inclusivity and mutual understanding. This can be achieved through education, which should focus on promoting cross-cultural awareness and respect. By learning about different cultures and perspectives, we can break down barriers and build bridges of understanding.In addition to education, we need to create spaces where diversevoices can be heard and respected. This includes promoting diverse representation in leadership positions and encouraging open dialogue and debate. By giving a platform to diverse voices, we can ensure that all perspectives are considered and valued.Moreover, individuals can play a crucial role in embracing diversity. We should strive to be more tolerant and understanding of people who are different from us. We can do this by challenging our own biases and assumptions and by actively seeking to understand others. By engaging in meaningful conversations and building relationships with people from different backgrounds, we can create a more inclusive and harmonious society.In conclusion, embracing diversity is crucial for global harmony and progress. By fostering an environment of inclusivity, promoting cross-cultural awareness, and challenging our own biases, we can harness the strength of diversity and create a world that is more understanding, inclusive, and prosperous.。
2021年温州市第九中学高三英语上学期期中试题及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AA medical capsule robot is a small,often pill-sized device that can do planned movement inside the body after being swallowed or surgically inserted. Most models use wireless electronics or magnets or a combination of the two to control the movement of the capsule. Such devices have been equipped with cameras to allow observation and diagnosis, with sensors that “feel,” and even with mechanical needles that administer drugs.But in practice, Biomechatronics engineer Pietro Valdastri has found that developing capsule models from scratch (从头开始) is costly, time-consuming and requires advanced skills. “The problem was we had to do them from scratch every time,” said Valdastri in an interview. “And other research groups were redeveloping those same modules from scratch, which didn’t make sense.”Since most of the capsules have the same parts of components: a microprocessor, communication submodules, an energy source, sensors, and actuators (致动器), Valdastri and his team made the modular platform in which the pieceswork in concertand can be interchanged with ease. They also developed a flexible board on which the component parts are snapped in like Legos. The board can be folded to fit the body of the capsule, down to about 14 mm. Additionally, they compiled (编译) a library of components that designers could choose from, enabling hundreds of different combinations. They arranged it all in a free online system. Designers can take the available designs or adapt them to their specific needs.“Instead of redeveloping all the modules from scratch, people with limited technological experience can use our modules to build their own capsule robots in clinical use and focus on their innovation,” Valdastri said.Now, the team has designed a capsule equipped with a surgical clip to stop internal bleeding. Researchers at Scotland’s Royal Infirmary of Edinburg have also expressed interest in using the system to make a crawling capsule that takes images of the colon(结肠). One research group, led by professors at the Institute of Digestive Disease of the Chinese University of HongKong, is making a swimming capsule equipped with a camera that pushes itself through the stomach.One limitation of Valdastri’s system is that it’s only for designing models. Researchers can confirm their hypotheses (假设) and do first design using the platform, but will need to move to a custom approach to develop their capsules further and make them practical for clinical use.1. According to the passage, Valdastri and his team created the platform to ________.A. adopt the latest technologiesB. make their robots dream come trueC. help build specialized capsule robotsD. do preciser observation and diagnosis2. What does the underlined phrase “work in concert” mean in Para.3?A. Perform live.B. Run independently.C. Act in a cooperative way.D. Carry on step by step.3. What can be learnt from the passage?A. Valdastri’s system can’t provide a complete capsule creation.B. The modular platform is more useful than a custom approach.C. The capsules can move in human’s body automatically.D. It costs more to module the capsules on the board.BHumans have found an easy way to tell if others are lying. Recent research shows that the best way so far is being clever at how you ask questions and listen to the answers.Much of this research is based on the idea that telling a lie is simply harder mental work than telling the truth. Making up a story takes more effort than simply recording something that happened. And like a writer, a liar has to keep all the unreal details in his memory and sound believable when he explains them.One method that seems to work is asking them to tell their story in reverse order. This is harder when the story isn't true and makes it easier for you to tell they are lying. An even more basic way that helps is to just ask more questions, especially unexpected ones. Truth-tellers can easily find more to say, but it's a challenge for a liar to come up with something that's not in his prepared story.Researchers suggest that you shouldn't lay all your cards on the table at the start, but only gradually present what proof you have. The liars' stories may not agree with that proof, making it clear that they're lying.So it looks like there are ways to increase the chances of catching a liar; we've just been basing our methods on the wrong stories. Low-tech ways of causing people to make mistakes in conversation seem to work better than any science about eye movement or machines used to recognize a liar. To find a liar, watch less and listen more.4. Why does the author mention the writer?A. To show it's hard to make up lies.B. To show it's hard to recognise a liar.C. To show writers know liars best.D. To show writers are very clever.5. What do we know about liars?A. They often have much to say.B. They often ask many questions.C. They usually prepare a made-up story.D. They usually feel good about themselves.6. What advice is given to help people catch liars?A. Asking them to set their stories down.B. Presenting your proof one by one.C. Telling different stories to them.D. Letting them ask questions.7. Which can be the best title for the text?A. Why People LieB. How to Stop People LyingC. Low-tech Ways to Find a LiarD. LiarsAre Smarter than ThoughtCLas Vegascity inNevadais built in a desert. The city may be known to the outside world for its partying. But officials have found that there are 21 square kilometers of useless grass. The grass is never laid on, played on or even stepped on. The grass is only there to look nice.Now, the city is asking theNevadastate legislature to ban useless grass. It is trying to become the first place inAmericato ban that kind of grass often seen between streets, in housing developments and in office parks.It is estimated that useless grass makes up 40% of all the grass inLas Vegasand it needs a lot of water to survive. Grass needs four times more water than dry climate plants like cactus. By tearing out the grass, the city could reduce yearly water usage by 15%.In 2003, the Southern Nevada Water Authority banned developers from planting grass in front of new homes. It also offered homeowners $ 30 for each square meter of grass they tear out. But fewer people are now using the program. Water usage has increased in southernNevadaby 9% since 2019. And last year,Las Vegaswent a record 240 days without major rainfall. The Colorado River provides much ofNevada's drinking water. The river could lose more water as climate change affects it.Water officials in other dry cities said water usage needs to be reduced. But they fear the reaction to reforms like the ones inLas Vegasif their communities do not accept them. Cynthia Campbell is the water resources adviser for the city ofPhoenixinArizona. “There might come a point when city restrictions get too severe for some residents. They'll say that is the point of no return for them,”Campbellsaid. “For some people, it's a pool. For some people, it's grass.”8. Why doesLas Vegascity try to ban useless grass?A. To protect the local people.B. To beautify the city.C. To reduce water usage.D. To reduce waste.9. What program was carried out inLas Vegasin 2003?A. Allowing planting grass before new houses.B. Encouraging the residents to tear out grass.C. Praising those who signed on the program.D. Awarding those who reduced water usage.10. What is implied inCampbell's words in the last paragraph?A. Many residents won't follow the ban.B. Reaction to the reform will vary personally.C. Other measures should be taken to protect wetter.D. Water officials should take many factors into account.11. What is the best title for the text?s VegasPlans to Ban Useless GrassB. A Method Is Adopted to SaveLas VegasC. Choices between Beauty and PracticeD. Grass Is Important but Useless inLas VegasDWhen Alex Linwas 11 years old, he read an alarming article in the newspaper, which said that people were burying old computers in backyards, throwing TVs into streams, and dumping (丢弃) cell phones in the garbage. This was dangerous because e-waste contains harmful chemicals that can leak into the environment, getting into crops, animals, water supplies and people.Alex was really worried and decided to make it next project for WIN-the Westerly Innovations Network. Alex and six of his friends had formed this organization to help solve community problems two years before.But what could they do about this project with e-waste? The team spent several weeks gathering information about the harmful chemicals in e-waste and their effects on humans. They learned how to dispose(处置) of e-waste properly and how it could be recycled. Then, they sent out a Survey and found only one in eight know what e-waste was, let alone how to properly dispose of it.Alex and his friends went into action. They advertised in the local newspaper and distributed notices to students, asking residents to bring their unwanted electronics to the school parking lot. The drive lasted two days,and they collected over 9, 500 kilograms of e-waste. The next step was to set up a long-term e-waste drop-off center for the town. After some research, they’d learned that reusing is the best way to deal with electronic devices and it is seven times more efficient than recycling. So, they began learning to retrofit (翻新) computers themselves and distributed them to students who didn’t have their own. In this way, they could help students in the area and protect the environment at the same time.For a lasting solution to e-waste, the drop-off center wasn’t enough. Lawswould have to be passed. In 2016, WIN helped push for an e-waste bill in their town, which required companies that manufactured or sold electronics to take back e-waste. The bill clearly forbids the dumping of e-waste. Because of the work of WIN, more and more people, like Alex and his team, are getting the message about safe disposal of e-waste. As Alex says, “Today’s technology should not become tomorrow’s harmful garbage.”12. What was Alex’s worry after he read the article?A. The littering of e-waste.B. The recycling of plastic.C. The change of environment.D. At 11 p.m. on Monday.13. What did Alex do to start the project?A. Set up WIN.B. Collect information.C. Ask friends for help.D. The overuse of old computer.14. Which can best describe the way Alex and his team did their work?A. Traditional.B. Competitive.C. Scientific.D. Convenient.15. What message does the story convey?A. There is no end to perfection.B. success comes through failure.C. Every positive attitude has a reward.D. young people can make a big difference.第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
Diversity Creation Methods:A Survey and CategorisationGavin Brown,Jeremy Wyatt,Rachel Harris,Xin YaoUniversity of Birmingham,School of Computer ScienceEdgbaston Park Road,Birmingham,B152TT,UK/˜gxb/g.brown@AbstractEnsemble approaches to classification and regression have attracted a great deal of interest in recent years.These methods can be shown both theoretically and empirically to outperformsingle predictors on a wide range of tasks.One of the elements required for accurate predictionwhen using an ensemble is recognised to be error“diversity”.However,the exact meaning ofthis concept is not clear from the literature,particularly for classification tasks.In this paperwefirst review the varied attempts to provide a formal explanation of error diversity,includingseveral heuristic and qualitative explanations in the literature.For completeness of discussionwe include not only the classification literature but also some excerpts of the rather more matureregression literature,which we believe can still provide some insights.We proceed to surveythe various techniques used for creating diverse ensembles,and categorise them,forming apreliminary taxonomy of diversity creation methods.As part of this taxonomy we introducethe idea of implicit and explicit diversity creation methods,and three dimensions along whichthese may be applied.Finally we propose some new directions that may prove fruitful inunderstanding classification error diversity.1IntroductionCreating diverse sets of classifiers is one of the keys to success in multiple classifier systems.Yet this is not easy,and our understanding of classifier error diversity is still incomplete.While we have many measures of diversity from the numerical taxonomy literature[1],we do not yet have a complete grounded framework;neither do we have a useful guide through the myriad of techniques by which we could create such error diversity.While ensemble approaches to classification usually make use of non-linear combination methods like majority voting;regression problems are naturally tackled by linearly weighted ensembles.These type of ensembles have a much clearer framework for explaining the role of diversity than voting methods.In particular the Ambiguity decomposition[2]and bias-variance-covariance decomposition [3]provide a solid quantification of diversity for linearly weighted ensembles by connecting it back to an objective error criterion:mean squared error.We believe that this can yet provide some insights into diversity in classification problems.The significant contribution of the paper is a survey and categorisation of the many ad-hoc methods for diversity creation in a classification context.We fully acknowledge that to embarkupon such a venture welcomes debate,and can never result in aflawless categorisation of thefield. With this in mind we note that a useful taxonomy should achieve two things:firstly to allow us to spot gaps in the literature,allowing us to explore new techniques,and secondly to allow us to measure the‘distance’between existing techniques;this would afford us some form of metric which could group techniques into families by how well they can perform in different application domains. We believe our study achieves the former of these two,allowing us to identify locations in the space of possible ensemble techniques that have not yet been exploited.We suggest studies akin to Friedman’s ISLE framework on importance sampling ensembles[4]will give insights into the latter challenge.In the next section we provide explanations of why ensembles can work well.This leads in Sec-tion2.1to a description of the existing formal accounts of diversity in the case of regression using a linearly weighted ensemble.As part of this we explicitly show the link between the bias-variance-covariance and Ambiguity decompositions.Attempts to characterise diversity for classification prob-lems are dealt with in Section2.3.In Section3we describe our proposed taxonomy of diversity creation methods.Discussions of some important issues in ensemble learning are given in Section4. Finally,conclusions and future research directions are presented in Section5.2When is an Ensemble Better than a Single Learner?In this section we scrutinise the concept of error“diversity”.We review existing explanations of why ensembles with diverse errors perform well;for completeness of the discussion we include the literature for both the regression and classification case.In the process of this we clarify a subtle point,often overlooked,to do with quantifying classifier ensemble diversity and the inherent non-ordinality of the predictor outputs.We proceed with a review of the literature on attempts to create diversity in both forms.We comment on the structure of thefield and in the following section propose a novel way to categorise the many ad-hoc diversity creation techniques.2.1In a Regression ContextThefirst major study on combining regression estimators was by Perrone[5](in fact at the same time,and independently,Hashem[6]developed many of the same results).This was thefirst study in the Machine Learning literature,but the topic has been covered in other research communities for several years,for example infinancial forecasting:Bates and Granger[7,8],and Clemen[9].As a consequence,the understanding of diversity here is quite mature,as we will now show.First,as an illustrative scenario,consider a single neural network approximating a sine wave;our network has been supplied with a limited set of data points to train on,the inputs chosen randomly at uniform from[−π,π],and a small amount of Gaussian noise added to the outputs.Now,consider a single testing data point,tofind the value of sin(2).The true answer is∼0.909,yet we know our network may possibly overpredict or underpredict that value.The way in which it makes errors will follow a distribution dependent on the random training data sample it received,and also on the random initialisation of the weights.The mean of this distribution is the expectation value E T W{f}, and f is a network trained with a particular dataset drawn according to a random variable T and a particular weight initialisation drawn according to a random variable W.Throughout the paper the expectation operator E{·}is with respect to these two random variables.It should also be noted that for convenience we have omitted the input vector,so E{f}would normally be E{f(x)}.In addition all observations we present are with respect to a single pattern,but the results easily generalise to the full space by integrating over the joint input density P(x,d).Figure1illustrates a typical error distribution,with the target value d shown.The four crosses marked are estimates of sin(2)from a hypothetical network;the estimates differ only in that the network was started from different initial weights each time.d=0.909Figure1:Typical error distribution of an unbiased estimator approximating sin(2) From this viewpoint we can immediately see the parallels to an ensemble system.Each member of an ensemble is a realisation of the random variable defined by this distribution over all possible training datasets and weight initialisations.The ensemble output is the average of this set of realisations;all our diversity promoting mechanisms are there to encourage our sample mean¯f to be a closer approximation to E T,W{f}.If we have a large ensemble,we have a large sample from this space;consequently with a large sample we can expect that we have a good approximation to the mean,E T,W{f}.If we have a smaller ensemble,we cannot expect this:our sample mean may be upward or downward biased.In order to correct this,some methods,such as Bagging[10],construct our networks from different training datasets,allowing us to sample a more representative portion of the space.This illustration assumes that the expected value of our estimator is equal to the true target value,i.e.an unbiased estimator.If this is not the case,we may have the situation infigure2.Figure2:Typical error distribution of a biased estimator approximating sin(2) Here,our estimator is upward biased,i.e.E{f}=d,its expected value E{f}is high of the target d.In this case,even if we sample many times from this distribution,we will not be able to estimate the target accurately with a simple average combination as the simple average will converge to E{f}as we add more networks.We would need to non-uniformly weight the outputs, giving higher weights to the networks predicting lower values.This is of course a purely hypotheticalscenario,we could not look this closely at every single data point to manually set the weights for the combination,but it does serve to illustrate that the chance of an error could be reduced by using a combination of several predictors rather than one.This intuition can be more formalised as the Ambiguity Decomposition.2.1.1The Ambiguity DecompositionKrogh and Vedelsby[2]proved that at a single data point the quadratic error of the ensemble estimator is guaranteed to be less than or equal to the average quadratic error of the component estimators:(f ens−d)2= i w i(f i−d)2− i w i(f i−f ens)2,(1) where f ens is a convex combination( i w i=1)of the component estimators:f ens= i w i f i(2)The details of the original proof from[2]were omitted for the authors’space considerations.However, this can in fact be shown more simply by the same manipulations as used in the bias-variance decomposition[11],reflecting a strong relationship between the two decompositions.We present this alternative version here:i w i(f i−d)2= i w i(f i−f ens+f ens−d)2= i w i (f i−f ens)2+(f ens−d)2+2(f i−f ens)(f ens−d)= i w i(f i−f ens)2+(f ens−d)2(f ens−d)2= i w i(f i−d)2− i w i(f i−f ens)2(3)This was a very encouraging result for ensemble research,providing a very simple expression for the effect due to error correlation in an ensemble.In section4we will see how a number of researchers have exploited this result in various ways to influence the design of their ensemble learners.The significance of the Ambiguity decomposition is that it shows us that if we have any given set of predictors,the error of the convex-combined ensemble will be less than or equal to the average error of the individuals.Of course,one of the individuals may in fact have lower error than the average, and lower than even the ensemble,on a particular pattern.But,given that we have no criterion for identifying that best individual,all we could do is pick one at random.One way of looking at the significance of the Ambiguity decomposition is that it tells us that taking the combination of several predictors would be better on average over several patterns,than a method which selected one of the predictors at random.The decomposition is made up of two terms.Thefirst, i w i(f i−d)2,is the weighted average error of the individuals.The second, i w i(f i−f ens)2is the Ambiguity term,measuring the amount of variability among the ensemble member answers for this pattern.Since this is always positive,it is subtractive from thefirst term,meaning the ensemble is guaranteed lower error than the averageindividual error.The larger the Ambiguity term,the larger the ensemble error reduction.However, as the variability of the individuals rises,so does the value of thefirst term.This therefore shows that diversity itself is not enough,we need to get the right balance between diversity(the Ambiguity term)and individual accuracy(the average error term),in order to achieve lowest overall ensemble error.The Ambiguity decomposition holds for convex combinations,and is a property of an ensemble trained on a single dataset.Unlike the bias-variance decomposition,it does not take into account the distribution over possible training sets or possible weight initialisations.What we are interested in, of course,is the expected error on future data points given these distributions.The Bias-Variance-Covariance decomposition[3]takes exactly this into account.2.2Bias,Variance and CovarianceThe concept of ensemble diversity for regression estimators can be understood further if we examine the bias-variance decomposition[11]for an ensemble.The bias-variance decomposition for quadratic loss states that the generalisation error of an estimator can be broken down into two components: bias and variance.These two usually work in opposition to one other:attempts to reduce the bias component will cause an increase in variance,and vice versa.The decomposition[11]is as follows: E{(f− d )2}=E{(f−E{f})2}+(E{f}− d )2MSE(f)=var(f)+bias(f)2Where d is the expected value of the target point given the noise.If the estimator here is a convex combined ensemble,the variance component breaks down further,and we have the Bias-Variance-Covariance decomposition[3].To clearly understand this,we define three concepts.The first is bias,the averaged bias of the ensemble members:bias=1M i(E{f i}− d )(4)The second is var,the averaged variance of the ensemble members:var=1M i E{(f i−E{f i})2}(5)The third is covar,the averaged covariance of the ensemble members:covar=1M(M−1) i j=i E{(f i−E{f i})(f j−E{f j})}(6)This gives us the bias-variance-covariance decomposition of mean-square error:E{[ 1M i f i − d ]2}=bias2+1M var+ 1−1M covar(7)We can see the mean square error of an ensemble of networks depends critically on the amount of error correlation between networks,quantified in the covariance term.We would ideally like to decrease the covariance,without causing any increases in the bias or variance terms.It is worth noting that while bias and variance are constrained to be positive-valued,the covariance term can be negative.2.2.1The Connection Between Ambiguity and CovarianceWe now show the exact link between the two decompositions we have just described.We know that (¯f−d)2can be expressed in terms of the Ambiguity decomposition.We also know that this is a property of using a quadratic loss function with a convex combination of predictors,and not specific to any particular target value.Therefore we could use the expected value of the target data, d ;in this case we re-express(¯f− d )2in terms of the average quadratic error and the Ambiguity term. Using d instead of d,we substitute the right hand side of equation(1)into the left hand side of equation(7).E{1M i(f i− d )2−1M i(f i−¯f)2}=bias2+1M var+1−1M covar(8)It would be interesting to understand what portions of the bias-variance-covariance decomposi-tion correspond to the Ambiguity term and which portions to the’average individual error’term. After some manipulations(for details see[12])we can show:E{1M i(f i− d )2}=(E{¯f}− d )2+1M i E (f i−E{¯f})2=bias(¯f)2+Ω(9)E{1M i(f i−¯f)2}=1M i E{(f i−E{¯f})2}−E{(¯f−E{¯f})2}=Ω−var(¯f)=Ω− 1M var+ 1−1M covar (10)where theΩterm is an interaction between the two sides:Ω=1M i E{(f i−E{¯f})2}(11)ThisΩterm is present in both sides—when we combine them by subtracting the Ambiguity in equation(10),from the average MSE in equation(9),the interaction terms cancel out,and we get the original bias-variance-covariance decomposition back,as in the RHS of equation(8).But what does theΩterm mean?If we examine it a little further:1M i E{(f i−E{¯f})2}=1M i E{(f i−E i{f i}+E i{f i}−E{¯f})2}=1M i E i{(f i−E i{f i})2}+1M i(E i{f i}−E{¯f})2=var+“deviationsThis is the average variance of the estimators,plus the average squared deviation of the ex-pectations of the individuals from the expectation of the ensemble.The fact that the interaction exists illustrates why we cannot simply maximise Ambiguity without affecting the other parts of the error—in effect,this interaction quantifies the diversity trade-offfor regression ensembles.In this section we have tried to give an intuition of why diversity among ensemble members that are averaged together can be a good idea.It should be noted that the framework around these two decompositions has told us merely how to quantify diversity,not how to achieve it in these types of ensemble.In addition we have said nothing yet about ensemble schemes involving other types of combination,such as voting or other non-linear schemes.We will address this in the next section.2.3In a Classification ContextWe have shown that in a regression context,we can rigorously define why and how differences between individual predictor outputs contribute toward overall ensemble accuracy.In a classification context,there is no such neat theory.There is a subtle point here,often overlooked.The difficulty in quantifying classification error diversity is not intrinsic to ensembles tackling classification problems. It is possible to reformulate any classification problem as a regression one by choosing to approximate the class posterior probabilities;this allows the theory we have already discussed to apply,and work is progressing in this area,notably Tumer and Ghosh[13]and Roli and Fumera[14,15].For the regression context discussed in the previous section,the question can be clearly phrased as“how can we quantify diversity when our predictors output real-valued numbers and are combined by a convex combination?”.For the case that Tumer and Ghosh[13]study,the question is the same,just that the“real-valued”numbers are probabilities.A much harder question appears when we are restricted such that our predictors can only output discrete class labels,as we have with Decision Trees or k-nearest neighbour classifiers.In this case,the outputs have no intrinsic ordinality between them, and so the concept of“covariance”is undefined.This non-ordinality also implies that we have to change our combination function—a popular one is majority voting between the individual votes. The harder question can therefore be phrased as,“how can we quantify diversity when our predictors output non-ordinal values and are combined by a majority vote?”.Taking all these into account,there is simply no clear analogue of the bias-variance-covariance decomposition when we have a zero-one loss function.We instead have a number of highly restricted theoretical results,each with their own assumptions that are probably too strong to hold in practice. Wefirst describe the very well-known work by Tumer and Ghosh,on combining posterior probability estimates(ordinal values),and then turn to considering the harder question of non-ordinal outputs.2.3.1Ordinal OutputsTumer and Ghosh[16,13]provided a theoretical framework for analysing the simple averaging combination rule when our predictor outputs are estimates of the posterior probabilities of each class,as infigure3.For a one dimensional feature vector x,the solid curves show the true posterior probabilities of classes a and b,these are P(a)and P(b),respectively.The dotted curves show estimates of thex*x *Figure 3:Tumer &Ghosh’s framework [16,13]for analysing classifier errorposterior probabilities,from one of our predictors,these are ˆP(a )and ˆP (b ).The solid vertical line at x ∗indicates the optimal decision boundary ,that is the boundary that will minimise error given that our posterior probabilities overlap.This overlap,the dark shaded area,is termed the Bayes error ,and is an irreducible quantity.The dotted vertical line at ˆx ∗indicates the boundary placed by our predictor,which is a certain distance from the optimal.The light shaded area indicates the added error that our predictor makes in addition to the Bayes error.The individual predictor i approximates the posterior probability of class a as:ˆP i (a |x )=P (a |x )+ηi (a |x )(12)where P (a |x )is the true posterior probability of class a and ηi (a |x )is the estimation error.Let us assume the estimation errors on different classes a and b are independent and identically distributed random variables [16,p5]with zero mean and variance σ2ηi .Consider the predictor’s expected added error in distinguishing classes a and b ,i.e.the expected size of the light shaded area given the variance σ2ηi.This can be stated as:E add,i =2σ2ηi P (a |x )−P (b |x )(13)where P (a |x )is the derivative of the true posterior probability of class a .If the decision boundary was instead placed by an ensemble of predictors,Tumer and Ghosh show the expected added error of the ensemble estimator is:E ens add =E add 1+δ(M −1)M(14)where M is the number of classifiers.E add is the expected added error of the individual classifiers:they are assumed to have the same error.The δis a correlation coefficient (see [17]for details)measuring the correlation between errors in approximating the posterior probabilities,therefore thisis a direct measure of diversity1.Ifδis zero,i.e.the classifiers in the ensemble are statisticallyindependent in their posterior probability estimates.Then we have E ensadd =1ME add,the error of theensemble will be M times smaller than the error of the individuals.Ifδis1,i.e.perfect correlation, then the error of the ensemble will just be equal to the average error of the individuals.To achieve this simple expression they assume that the errors of the different classifiers havethe same varianceσ2ηi .Another,possibly less critical assumption is that the posterior probabilitiesare monotonic around the decision boundary.This work has recently been extended by Roli and Fumera[14,15],allowing for some of the assumptions to be lifted,the most important of which is that it allows for non-uniformly weighted combinations.This demonstrates that the understanding of this particular diversity formulation(when outputting posterior probabilities)is progressing.What seems to be a sticking point for ensemble research is the non-ordinal output case,as we will now illustrate.2.3.2Non-Ordinal OutputsIn ensemble research,Hansen and Salamon[18]is seen by many as the seminal work on diversity in neural network classification ensembles.They stated that a necessary and sufficient condition for a majority voting2ensemble of classifiers to be more accurate than any of its individual members is if the classifiers are accurate and diverse.An accurate classifier is one that has an error rate of better than random guessing,on new input.Two classifiers are diverse if they make different errors on new data points.They used the binomial theorem to explain this;we assume that all networks arrive at the correct classification for a given pattern with probability(1−p),and that they make statistically independent errors.This gives the following probability of a majority voted ensemble being in error:P(ensemble incorrect)=Mk>(M/2) M k p k(1−p)(M−k)(15)This expressed the probability of ensemble error at a single testing data point.For example, with an ensemble of21predictors,combined with a majority vote,there would have to be at least 11members wrong in order for the whole ensemble to be wrong.The area under the binomial distribution for11or more,and therefore the probability of the ensemble being incorrect,is0.026. It should be stressed though,this only applies when the predictors are statistically independent, an assumption that is too strong to ever hold in practice,but it does represent the theoretical(if unachievable)ideal.Breiman[19]presents an upper bound on the error of Random Forests—ensembles of decision trees constructed via a particular randomization technique.This is a bound on the generalisation error,so integrated over all possible training sets:P(ensemble generalization error)≤¯ρ(1−s2)s2(16) where s is the‘strength’of the ensemble,expressed as the expected size of the margin by which the ensemble achieves the correct labelling,and¯ρis the averaged pairwise correlation between Oracle 1In fact Tumer and Ghosh rely fundamentally on many of the same manipulations as used in the bias-variance-covariance decomposition—it would be very interesting to see this link made explicit.2They also present results for plurality voting,which turns out to be far more complex.outputs.Although the bound is not very tight,Kuncheva comments that it can be regarded as a piece of“that yet missing more general theory of diversity”[20].We will comment further on the nature of this problem in section4.From this point onwards,when referring to“classification error diversity”,it can be assumed that we are referring to this difficult task of quantifying non-ordinal output diversity.From the description of the problem as we have clearly stated,it seems deriving an expression for classification diversity is not as easy as it is for regression.The ideal situation would be a parallel to the regression case, where the squared error of the ensemble can be re-expressed in terms of the squared errors of the individuals and a term that quantifies their correlation.We would like to have an expression that similarly decomposes the classification error rate into the error rates of the individuals and a term that quantifies their‘diversity’.At present,this is beyond the state of the art,however a number of empirical investigations have gone into deriving heuristic expressions that may approximate this unknown diversity term.2.3.3A Heuristic Metric for Classification Error Diversity?A number of authors have tried to qualitatively define classification error diversity.Sharkey[21] suggested a scheme by which an ensemble’s pattern of errors could be described in terms of a level of diversity.It should be noted that this work concentrated on neural networks,but the ideas are equally applicable to any type of classifier.Four levels were proposed,each one describing the incidence and effect of coincident errors amongst the members of the ensemble and the degree to which the target function is covered by the ensemble.A coincident error occurs when,for a given input,more than1ensemble member gives an incorrect answer.Function coverage is an indication of whether or not a test input yields a correct answer on ANY of the individuals in the ensemble.Level1No coincident errors,the target function is covered.Majority vote always produces the correct answer.Level2Some coincident errors,but the majority is always correct and the function is completely covered.The ensemble size must be greater than4for this to hold.Level3A majority vote will not always yield the right answer,but the members of the ensemble cover the function such that at least one always has the correct answer for a given input. Level4The function is not always covered by the members of the ensemble.Sharkey acknowledges that ensembles exhibiting level2or3diversity could be“upwardly mobile”as it is possible that an ensemble labelled as having level2diversity could contain a subset of members displaying level1diversity using the test set and a level3ensemble could contain subsets of members displaying level1and/or level2diversity on the test set,thus removal of certain members could result in a change of diversity level for the better.One problem with this heuristic is that it gives no indication of how typical the error behaviour described by the assigned diversity level is,with respect to the test data,nor does it tell us how to generate this diversity.According to this metric for denoting error diversity,Sharkey assigns the level which describes the worst case observed;this could happen on the basis of the ensemble performance on only one example from the test data.For example,an ensemble could perform consistently with level1diversity on most of a test dataset,then fail on only a single pattern,which would mean that an otherwise good ensemble could be demoted to level4diversity.Table1showsthe maximum number of classifiers allowed to be in error for a single test pattern in order for each diversity level to hold.Level Maximum networks in error112M2−1if M is even,or M−12if M is odd3M−14MTable1:Maximum allowable networks in error for each of Sharkey’s diversity levels to hold on a single test pattern.This heuristic is therefore sufficient for illustrative purposes,but intuitively it can be seen that a particular multi-classifier system could exhibit different diversity levels on different subsets of a dataset.These levels may act as a better indication of the ensemble’s pattern of errors if they are coupled with the proportions of the test data for which it performs at the described levels.Thus, a distribution of error diversity levels observed during testing could be produced to describe the performance of an ensemble.For example,given a test set of100patterns it is plausible that all4 diversity levels could be observed,as we show in table2.Here,for thefirst ensemble,20of the data examples produce level1diversity,whereas on the second ensemble,55examples produce level1, indicating that the second ensemble has lower error.Level1Level2Level3Level4Ensemble120254015Ensemble25525155Table2:Distribution of diversity levels across a dataset(number of patterns exhibiting each level of diversity)for two hypothetical ensembles.According to Sharkey both of these ensembles would be assigned to level4diversity despite the fact that the second ensemble performs better than thefirst as shown by adding in the proportions with which the different levels of diversity occur.This suggested improvement does not,however, give any indication as to which members of the ensemble are responsible for which proportions of the different levels of error.Carney and Cunningham[22]suggested an entropy-based measure,though this does not allow calculation of an individual’s contribution to overall diversity.Zenobi and Cunningham[23]proposed a measure of classification Ambiguity.The Ambiguity of the i th classifier,averaged over N patterns, isA i=1NNn=1a i(x n)(17)。