Quasi-experimental designs本

Unit11、Some factors that may lead to the complaint:·Neuron overload·Patients* high expectations·Mistrust and misunderstanding between the patient and the doctor2、Mrs. Osorio’s condition:·A 56-year-old woman·Somewhat overweight·Reasonably well-controlled diabetes and hypertension·Cholesterol on the high side without any medications for it·Not enough exercises she should take·Her bones a little thin on her last DEXA scan3、Good things:·Blood tests done·Glucose a little better·Her blood pressure a little better but not so great Bad things:·Cholesterol not so great·Her weight a little up·Her bones a little thin on her last DEXA scan 44、The situation:·The author was in a moderate state of panic: juggling so many thoughts about Mrs. Osorio’s conditions and trying to resolve them all before the clock ran down.·Mrs. Osorio made a trivial request, not so important as compared to her conditions.·Mrs. Osorio seemed to care only about her “innocent —and completely justified —request”：the form signed by her doctor.·The doctor tried to or at least pretended to pay attention to the patient whilecompleting documentation.5、Similarities:·In computer multitasking, a microprocessor actually performs only one task at a time. Like microprocessors, we human beings carft actually concentrate on two thoughts at the same exact time. Multitasking is just an illusion both in computers and human beings.Differences:·The concept of multitasking originated in computer science.·At best, human beings can juggle only a handful of thoughts in a multitasking manner, but computers can do much better.·The more thoughts human beings juggle, the less human beings are able to attune fully to any given thought, but computers can do much better.6、·7 medical issues to consider·5 separate thoughts, at least, for each issue·7 x 5 = 35 thoughts·10 patients that afternoon·35 x 10 = 350 thoughts·5 residents under the authors supervision·4 patients seen by each resident·10 thoughts, at least, generated from each patient·5 x 4 x 10 = anther 200 thoughts·350 + 200 = 550 thoughts to be handled in total·If the doctor does a good job juggling 98% of the time, that still leaves about 10 thoughts that might get lost in the process.7、Possible solutions:·Computer-generated reminders·Case managers·Ancillary services·The simplest solution: timeUnit21、The author implies:• Peoples inadequate consciousness about the consequence of neglecting the re-emerging infectious diseases·Unjustifiability of peoples complacency about the prevention and control of the infectious diseases·Unfinished war against infectious diseases2、Victory declarations:·Surgeon General William Stewart's hyperbolic statement of closing “the book on infectious disease”.·A string of impressive victories incurred by antibiotics and vaccines·The thought that the war against infectious diseases was almost overWhat followed ever since:·Appearance of new diseases such as AIDS and Ebola·Comeback of the old afflictions:» Diphtheria in the former Soviet Union» TB in urban centers like New York City» Rising Group A streptococcal conditions like scarlet fever·The fear of a powerful new flu strain sweeping the world3、Elaborate on the joined battle:·WHO established a new division devoted to worldwide surveillance and control of emerging disease in October 1995.·CDC launched a prevention strategy in 1994.·Congress raised fund from $6.7 million in 1995 to $26 million in 1997.4、The borders are meaningless to pathogenic microbes, which can travel from one country to another remote country in a very short time.5、TB:·Prisons and homeless shelters as ideal places for TB spread·Emerging of drug-resistant strain or even multi-drug-resistant strain·A ride on the HIV w^on by attacking the immunocompromisedGroup A strep:·A change in virulence·Mutation in the exterior of the bacteriumFlu:Constant changes in its coat (surface antigens) and resultant changes in its level of virulence6、Examples:·Experiment in England is seeing the waning immunity because of no vaccination. ·Du e to poor vaccination efforts, the diphtheria situation in the former Soviet Union is serious. '• The vaccination rates are dropping in some American cities, and it will lead to more diphtheria and whooping cough.7、The four areas of focus:·The need for surveillance·Updated science capable of dealing with discoveries in the field·Appropriate prevention and control·Strong public health infrastructure8、The infectious diseases such as TB, flu, diphtheria and scarlet fever will never really go away, and the war against them will never end.Unit31、Terry's life before·She loved practicing Tae Kwon Do·She loved the surge of adrenaline that came with the controlled combat of tournaments.·She competed nationally, even won bronze medal in the trials for the Pan American Games.·She attended medical school, practiced as an internal medicine resident, and became an academic general internist.·She got married and got a son and a daughter.2、The symptoms of MS and autoimmune disease:·Loss of stamina and strength·Problems with balance·Bouts of horrific facial pain·Dips in visual acuity3、Terry did the following before she self-experimented:·She started injections.·She adopted many pharmacotherapies.·She began her own study of literature:» She read articles on websites such as PubMed.» She searched for articles testing new MS drugs in animal models.» She turned to articles concerning neurodegeneration of all types — dementia，Parkinson's disease, Huntington's disease, and Lou Gehrig's disease.» She relearned basic sciences such as cellular physiology, biochemistry, and neurophysiology.4、Approaches Terry mainly used:·Self-experimentation with various nutrients to slow neurodegeneration based on literature reports on animal models·Self-experimentation with neuromuscular electrical stimulation which is not an approved treatment for MS·Online search to identify the sources of micronutrients and having a new diet ·Reduction of food allergies and toxic load5、Cases mentioned in the text:·Increased mercury stores in the brains of people with dental fillings·High levels of the herbicide atrazine in private wells in Iowa·The strong association between pesticide exposure and neurodegeneration ·The association of single nucleotide polymorphisms involving metabolism of sulfur and/or B vitamins·Inefficient clearing of toxins6、With 70% to 90% of the risk for diabetes, heart disease, cancer, andautoimmunity being due to environmental factors other than the genes, we can take many health problems and the health care crisis under our control, for example, optimizing our nutrition and reducing our toxic load.Unit41、Two concepts:·Complementary medicine refers to the use of conventional therapies together with alternative treatments such as using acupuncture in addition to usual care to help lessen pain. Complementary and alternative medicine is shortened as CAM.·Alternative medicine refers to healing treatments that are not part of conventional therapies —like acupuncture, massage therapy, or herbal medicine. They are called so because people used to consider practices like these outside the mainstream.2·TCM does not require advanced, complicated, and in most cases, expensive facilities.·TCM employs needles, cups, coins, to mention but a few.·Most procedures and operations of TCM are noninvasive.·The substances used as medicine are raw herbs or abstracts from them, and they are indeed all natural, from nature.·TCM has been practiced as long as the Chinese history, so the efficiency i s proven and ensured.·Ongoing research around the world on acupuncture, herbs, massage and Tai Chi have shed light on some of the theories and practices of TCM3、It may be used as an adjunct treatment, an alternative, or part of a comprehensive management program for a number of conditions: post-operative and chemotherapy induced nausea and vomiting, post-operative dental pain, addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma.4、A well-justified NO:·More intense research to uncover additional areas for the use of acupuncture ·Higher adoption of acupuncture as a common therapeutic modality not only in treatment but also in prevention of disease and promotion of wellness ·Exploration and perfection of innovative methods of acupuncture point stimulation with technological advancement·Improved understanding of neuroscience and other aspects of human physiology and function by basic research on acupuncture·Greater interest by stakeholders·An increasing number of physician acupuncturists5、·Appropriate uses of herbs depend on proper guidance:» Proper TCM diagnosis of the zheng of the patient»Correct selection of the corresponding therapeutic strategies and principles that guide the choice of herbs and herbal formulas·Digression from either of the above guidence will lead to misuses of herbs, and will result in complications in patient6、·Randomized controlled trialsAdvantages:»Elimination of the potential bias in the allocation of participants to the intervention group or control group» Tendency to produce comparable groups» Guaranteed validity of statistical tests of significanceLimitations:» Difficulty in generalizing the results obtained from the selected sampling to the population as a whole»A poor choice for research where temporal factors are anissue»Extremely heavy resources, requiring very large samplegroups• Quasi-experimentsAdvantages:» Control group comparisons possible»Reduced threats to external validity as natural environments do notsuffer the same problems of artificiality as compared to a well-controlledlaboratory setting.»Generalizations of the findings to be made about population since quasiexperiments are natural experimentsLimitations：» Potential for non-equivalent groups as quasi-experimental designs donot use random sampling in constructing experimental and controlgroups.»Potential for low internal validity as a result of not using random sampling methods to construct the experimental and control groups• Cohort studiesAdvantages:»Clear indication of the temporal sequence between exposure and outcome» Particular use for evaluating the effects of rare or unusual exposure» Ability to examine multiple outcomes of a single risk factorLimitations:» Larger, longer, and more expensive» Prone to certain types of bias» Not practical for rare outcomes• Case-control studiesAdvantages:» The only feasible method in the case of rare diseases and those with long periods between exposure and outcome» Time and cost effective with relatively fewer subjects as compared to other observational methodsLimitations：» Unable to provide the same level of evidence as randomized controlled trials as it is observational in nature» Difficult to establish the timeline of exposure to disease outcome• “N=1” trialsAdvantages» Easy to manage» InexpensiveLimitations：» Findings difficult to be generalized to the whole population» Weakest evidence due to the number of the subject7、• Synthesis of evidence is completely dependent on:» The completeness of the literature search (unavailable for foreign studies)» The accuracy of evaluation·There are situations in which no answer can be found for the questions of interest in RCTs and database analyses.·There's the requirement of using less stringent information rather than “hard data”8、·Assessment of the intrinsic value of traditional medicine in society·Research and education·Political, economic, and social factorsUnit51、·Dis-ease refers to the imbalance arising from：» Continuous stress» Pain» Hardships·Disease is a health crisis ascribable to various dis-eases.·Prompting elimination of dis-eases can alleviate some diseases.2、·Wellness is a state involving every aspect of our being: body, mind and spirit.·Manifestations of a healthy person:» Energy and vitality» A certain zip in gait» A warm feeling of peace of heart seen through behavior3、·Constant messages, positive and negative，are sent to our mind about the health of our body.·Physical symptoms are suppressed by people who go through life on automatic pilot.·Being well equals to being disease- or illness-free in the minds of them.·They confused wellness with an absence of symptoms.4、·People's minds are infected by spin:» Half-truth» Fearful fictions» Blatant deceit: some as a form of self-deceit·Spin is a result of unconscious living.·The kind of falseness is pandemic.5·Our body intelligence is suppressed or dormant from a lack of use.·There are tremendous amount of stress on a daily basis.·Our bodies are easily ignored for years because of a lack of recreation time. ·Limiting, self-defeating and even self-destructive behaviors undermine our wellbeing and keep them from achieving our full potential.6·We grow more reluctant to take risks.·We lose the ability to feel and acknowledge our deepest feelings and the courage to speak our truth.·We continue to deny and repress our feelings to protect ourselves.·Fear, denial and disconnection from our bodies and feelings become an unconscious, self-protective habit, a kind of default response to life.7·A multi-faceted process:» Looking for roots of and resolutions for the issues in different dimensions» Building our wellness toolbox slowly» Picturing our whole state of being·Attention to the little stuff:» Examining our lives honestly and setting clear intentions to change» Striving to maintain a balance of our mind, body and spirit» Taking small steps in the way to perceive and resolve conflict8·Try to awaken and evolve in order to live more consciously.·Get in touch with our genuine feelings and emotions.·Come to terms with the toxic emotions1、In the past, most people died at home. But now, more and more people are caredin hospitals and nursing homes at their end of life, which of course brings a new set of questions to consider.2、·Sixty-four years old with a history of congestive heart failure·Deciding to do everything medically possible to extend his life·Availability of around-the-clock medical services and a full range of treatment choices, tests, and other medical care·Relaxed visiting hours, and personal items from home3、Availability of around-the-clock medical resources, including doctors, nurses, andfacility.4、·Taking on a job which is big physically, emotionally, and financially·Hiring a home nurse for additional help·Arranging for services (such as visiting nurses) and special equipment (like a hospital bed or bedside commode)5、·Health insurance·Planning by a professional, such as a hospital discharge plaimer or a social worker·Help from local governmental agencies·Doctor's supervision at home6、·Traditionally, it is only about symptom care.·Recently, it is a comprehensive approach to improving the quality of life for people who are living with potentially fatal diseases.·Stopping treatment specifically aimed at curing an illness equals discontinuing all treatment.·Choosing a hospice is a permanent decision.Unit71、·A dying patient·Decision whether to withdraw life-support machines and medication and start comfort measures·The family's refusal to make any decision or withdraw any treatments2、·The doctor as exclusive decision-maker·The patient as participant with little say in the final choice3、·Respect for the patient, especially the patient s autonomy·Patient-centered care·The patient as decision-maker based on the information provided by the doctor 4、·Patients are forced to make decisions they never want to.·Patients, at least a large majority of them, prefer their doctors to make final decisions.·Shifting responsibility of decision-making to patients will bring about more stress to patients and their families, especially when the best option for the patient is uncertain.5、Doctors are very much cautious about committing some kind of ethicaltransgression.6、·Shouldering responsibility together with the patient may be better than having the patient make decisions on their own.·Balancing between paternalism and respect for patients autonomy constitutes a large part of medical practice.Unit81、·Research:An activity to test hypothesis, to permit conclusions to be drawn, and thereby to develop or contribute to generalizable knowledge·Practice:Interventions solely to enhance the well-being of an individual patient or client and that have a reasonable expectation of success·Blurred distinction:» Cooccurrence of research and practice like in research designed to evaluate a therapy» Notable departures from standard practice being called “experimental” with the terms “experimenta l”and “research” carelessly defined2、·Autonomy：Individuals treated as autonomous agents .·Protection:Persons with diminished autonomy entitled to protection·A case in point:Prisoners involved in research3·“Do no harm” as the primary principle·Maximization of possible benefits and minimization of possible harms . ·Balance between benefits and potential risks involved in every step of seeding the benefits4、·“Do no harm” as a fundamental principle of medical ethics·Extension of it to the realm of research by Claude Bernard·Benefits and risks as a set “duet” in both medical practice and research5、·Unreasonable denial of entitled benefit and unduly imposed burden：Enrolment of patients in new drug trial: Who should be enrolled and who should not?·Equal treatment of equals:Determining factors of equality: age, sex, severity of the condition, financial status, social status6、·Definition:The opportunity to choose what shall or shall not happen to them ·Application:» A process rather than signing a written form» Adequate information as the premise» A well-informed decision as the expected result7、·Requirements for consent as entailed by the principle of respect for persons ·Risk/benefit assessment as entailed by the principle of beneficence·More requirements of fairness as entailed by the principle of justice: » At the individual level: fairness» At the social level: distinction between classes。

准实验研究的英语IntroductionExperimental research is a type of research design that involves manipulating one or more variables to observe the effect on another variable. However, in some situations, experimental research may not be feasible or ethical. In such cases, researchers may opt for quasi-experimental research, which is a type of research design that lacks the random assignment of participants to groups. This article explores quasi-experimental research, its types, advantages, and disadvantages.Types of Quasi-Experimental Research1. Pre-Experimental DesignsPre-experimental designs are the simplest type of quasi-experimental designs, and they involve measuring the dependent variable before and after an intervention. There are three types of pre-experimental designs: one-shot design, one-group pretest-posttest design, and static group comparison design.a. One-shot design: In this design, the researcher measures the dependent variable after the intervention. However, there is no control group, and hence, it isdifficult to determine whether the observed change is dueto the intervention or other factors.b. One-group pretest-posttest design: In this design,the researcher measures the dependent variable before and after the intervention. However, there is no control group, and hence, it is difficult to determine whether theobserved change is due to the intervention or other factors.c. Static group comparison design: In this design, the researcher compares the dependent variable in a group that received the intervention and a group that did not receive the intervention. However, the groups are not randomly assigned, and hence, there may be differences between the groups that may affect the results.2. Quasi-Experimental DesignsQuasi-experimental designs involve the manipulation ofan independent variable, but the participants are not randomly assigned to groups. There are four types of quasi-experimental designs: nonequivalent control group design,time-series design, interrupted time-series design, and regression-discontinuity design.a. Nonequivalent control group design: In this design, the researcher compares the dependent variable in a group that received the intervention and a group that did not receive the intervention. However, the groups are not randomly assigned, and hence, there may be differences between the groups that may affect the results.b. Time-series design: In this design, the researcher measures the dependent variable at multiple time points before and after the intervention. However, there is no control group, and hence, it is difficult to determine whether the observed change is due to the intervention or other factors.c. Interrupted time-series design: In this design, the researcher measures the dependent variable at multiple time points before and after the intervention. However, there is a control group, which allows the researcher to determine whether the observed change is due to the intervention or other factors.d. Regression-discontinuity design: In this design, the researcher selects participants based on a cutoff score on a continuous variable. Participants who score above the cutoff score receive the intervention, while those who score below the cutoff score do not receive the intervention. This design allows the researcher to determine whether the observed change is due to the intervention or other factors.Advantages of Quasi-Experimental Research1. Ethical ConsiderationsIn some situations, experimental research may not be ethical. For example, it may not be ethical to manipulate an independent variable that may harm participants. Quasi-experimental research provides an alternative to experimental research, which allows researchers to study the effect of an intervention without compromising the ethical considerations.2. Real-World SettingsQuasi-experimental research is often conducted in real-world settings, which enhances the ecological validity ofthe research findings. This means that the researchfindings are more likely to be applicable to real-world situations.3. Cost-EffectiveQuasi-experimental research is often less costly than experimental research. This is because it does not involve random assignment of participants to groups, which can be time-consuming and costly.Disadvantages of Quasi-Experimental Research1. Lack of ControlQuasi-experimental research lacks the control associated with experimental research. This means that there may be other factors that may affect the results, which may make it difficult to determine whether the observed change is due to the intervention or other factors.2. Selection BiasQuasi-experimental research may suffer from selection bias. This is because participants are not randomly assigned to groups, which may result in differences between the groups that may affect the results.3. Internal ValidityQuasi-experimental research may suffer from internal validity issues. This is because there may be other factors that may affect the results, which may make it difficult to determine whether the observed change is due to the intervention or other factors.ConclusionQuasi-experimental research is a type of research design that lacks the random assignment of participants to groups. It is often used in situations where experimental research may not be feasible or ethical. Quasi-experimental research has advantages such as being ethical, conducted in real-world settings, and cost-effective. However, it also has disadvantages such as lack of control, selection bias, and internal validity issues. Researchers should carefully consider the advantages and disadvantages of quasi-experimental research before deciding on the research design to use.。

Unit11、Some factors that may lead to the complaint:·Neuron overload·Patients* high expectations·Mistrust and misunderstanding between the patient and the doctor2、Mrs. Osorio’s condition:·A 56-year-old woman·Somewhat overweight·Reasonably well-controlled diabetes and hypertension·Cholesterol on the high side without any medications for it·Not enough exercises she should take·Her bones a little thin on her last DEXA scan3、Good things:·Blood tests done·Glucose a little better·Her blood pressure a little better but not so great Bad things:·Cholesterol not so great·Her weight a little up·Her bones a little thin on her last DEXA scan 44、The situation:·The author was in a moderate state of panic: juggling so many thoughts aboutMrs. Osorio’s conditions and trying to resolve them all before the clock ran down.·Mrs. Osorio made a trivial request, not so important as compared to her conditions.and completely justified ·Mrs. Osorio seemed to care only about her “innocent —：the form signed by her doctor.—request”·The doctor tried to or at least pretended to pay attention to the patient whilecompleting documentation.5、Similarities:·In computer multitasking, a microprocessor actually performs only one task at a time. Like microprocessors, we human beings carft actually concentrate on two thoughts at the same exact time. Multitasking is just an illusion both in computersand human beings.Differences:·The concept of multitasking originated in computer science.·At best, human beings can juggle only a handful of thoughts in a multitasking manner, but computers can do much better.·The more thoughts human beings juggle, the less human beings are able to attune fully to any given thought, but computers can do much better.6、·7 medical issues to consider·5 separate thoughts, at least, for each issue·7 x 5 = 35 thoughts·10 patients that afternoon·35 x 10 = 350 thoughts·5 residents under the authors supervision·4 patients seen by each resident·10 thoughts, at least, generated from each patient·5 x 4 x 10 = anther 200 thoughts·350 + 200 = 550 thoughts to be handled in total·If the doctor does a good job juggling 98% of the time, that still leaves about 10 thoughts that might get lost in the process.7、Possible solutions:·Computer-generated reminders·Case managers·Ancillary services·The simplest solution: timeUnit21、The author implies:? Peoples inadequate consciousness about the consequence of neglecting the re-emerging infectious diseases·Unjustifiability of peoples complacency about the prevention and control of theinfectious diseases·Unfinished war against infectious diseases2、Victory declarations:·Surgeon General William Stewart's hyperbolic statement of closing “the book on infectious disease”.·A string of impressive victories incurred by antibiotics and vaccines·The thought that the war against infectious diseases was almost overWhat followed ever since:·Appearance of new diseases such as AIDS and Ebola·Comeback of the old afflictions:? Diphtheria in the former Soviet Union? TB in urban centers like New York City? Rising Group A streptococcal conditions like scarlet fever·The fear of a powerful new flu strain sweeping the world3、Elaborate on the joined battle:·WHO established a new division devoted to worldwide surveillance and controlof emerging disease in October 1995.·CDC launched a prevention strategy in 1994.·Congress raised fund from $6.7 million in 1995 to $26 million in 1997.4、The borders are meaningless to pathogenic microbes, which can travel fromone country to another remote country in a very short time.5、TB:·Prisons and homeless shelters as ideal places for TB spread·Emerging of drug-resistant strain or even multi-drug-resistant strain·A ride on the HIV w^on by attacking the immunocompromisedGroup A strep:·A change in virulence·Mutation in the exterior of the bacteriumFlu:Constant changes in its coat (surface antigens) and resultant changes in its levelof virulence6、Examples:·Experiment in England is seeing the waning immunity because of no vaccination. ·Du e to poor vaccination efforts, the diphtheria situation in the former Soviet Union is serious. '? The vaccination rates are dropping in some American cities, and it will lead to more diphtheria and whooping cough.7、The four areas of focus:·The need for surveillance·Updated science capable of dealing with discoveries in the field·Appropriate prevention and control·Strong public health infrastructure8、The infectious diseases such as TB, flu, diphtheria and scarlet fever will never really go away, and the war against them will never end.Unit31、Terry's life before·She loved practicing Tae Kwon Do·She loved the surge of adrenaline that came with the controlled combat of tournaments.·She competed nationally, even won bronze medal in the trials for the Pan American Games.·She attended medical school, practiced as an internal medicine resident, and became an academic general internist.·She got married and got a son and a daughter.2、The symptoms of MS and autoimmune disease:·Loss of stamina and strength·Problems with balance·Bouts of horrific facial pain·Dips in visual acuity3、Terry did the following before she self-experimented:·She started injections.·She adopted many pharmacotherapies.·She began her own study of literature:? She read articles on websites such as PubMed.? She searched for articles testing new MS drugs in animal models.? She turned to articles concerning neurodegeneration of all types — dementia，Parkinson's disease, Huntington's disease, and Lou Gehrig's disease.? She relearned basic sciences such as cellular physiology, biochemistry, andneurophysiology.4、Approaches Terry mainly used:·Self-experimentation with various nutrients to slow neurodegeneration based on literature reports on animal models·Self-experimentation with neuromuscular electrical stimulation which is not an approved treatment for MS·Online search to identify the sources of micronutrients and having a new diet ·Reduction of food allergies and toxic load5、Cases mentioned in the text:·Increased mercury stores in the brains of people with dental fillings·High levels of the herbicide atrazine in private wells in Iowa·The strong association between pesticide exposure and neurodegeneration·The association of single nucleotide polymorphisms involving metabolism of sulfur and/or B vitamins·Inefficient clearing of toxins6、With 70% to 90% of the risk for diabetes, heart disease, cancer, andautoimmunity being due to environmental factors other than the genes, we cantake many health problems and the health care crisis under our control, for example, optimizing our nutrition and reducing our toxic load.Unit41、Two concepts:·Complementary medicine refers to the use of conventional therapies together with alternative treatments such as using acupuncture in addition to usual care to help lessen pain. Complementary and alternative medicine is shortened as CAM.·Alternative medicine refers to healing treatments that are not part of conventional therapies —like acupuncture, massage therapy, or herbal medicine. They are called so because people used to consider practices like these outside the mainstream.2·TCM does not require advanced, complicated, and in most cases, expensivefacilities.·TCM employs needles, cups, coins, to mention but a few.·Most procedures and operations of TCM are noninvasive.·The substances used as medicine are raw herbs or abstracts from them, andthey are indeed all natural, from nature.·TCM has been practiced as long as the Chinese history, so the efficiency i s proven and ensured.·Ongoing research around the world on acupuncture, herbs, massage and Tai Chi have shed light on some of the theories and practices of TCM3、It may be used as an adjunct treatment, an alternative, or part of a comprehensive management program for a number of conditions: post-operativeand chemotherapy induced nausea and vomiting, post-operative dental pain, addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma.4、A well-justified NO:·More intense research to uncover additional areas for the use of acupuncture ·Higher adoption of acupuncture as a common therapeutic modality not only in treatment but also in prevention of disease and promotion of wellness·Exploration and perfection of innovative methods of acupuncture point stimulation with technological advancement·Improved understanding of neuroscience and other aspects of human physiology and function by basic research on acupuncture·Greater interest by stakeholders·An increasing number of physician acupuncturists5、·Appropriate uses of herbs depend on proper guidance:? Proper TCM diagnosis of the zheng of the patient?Correct selection of the corresponding therapeutic strategies and principles that guide the choice of herbs and herbal formulas·Digression from either of the above guidence will lead to misuses of herbs, andwill result in complications in patient6、·Randomized controlled trialsAdvantages:?Elimination of the potential bias in the allocation of participants to the intervention group or control group? Tendency to produce comparable groups? Guaranteed validity of statistical tests of significanceLimitations:? Difficulty in generalizing the results obtained from the selected sampling to the population as a whole? A poor choice for research where temporal factors are anissue?Extremely heavy resources, requiring very large samplegroups? Quasi-experimentsAdvantages:? Control group comparisons possible?Reduced threats to external validity as natural environments do notsuffer the same problems of artificiality as compared to a well-controlledlaboratory setting.?Generalizations of the findings to be made about population since quasiexperiments are natural experimentsLimitations：? Potential for non-equivalent groups as quasi-experimental designs donot use random sampling in constructing experimental and controlgroups.?Potential for low internal validity as a result of not using random sampling methods to construct the experimental and control groups? Cohort studiesAdvantages:?Clear indication of the temporal sequence between exposure and outcome? Particular use for evaluating the effects of rare or unusual exposure? Ability to examine multiple outcomes of a single risk factorLimitations:? Larger, longer, and more expensive? Prone to certain types of bias? Not practical for rare outcomes? Case-control studiesAdvantages:? The only feasible method in the case of rare diseases and those with longperiods between exposure and outcome? Time and cost effective with relatively fewer subjects as compared to other observational methodsLimitations：? Unable to provide the same level of evidence as randomized controlled trialsas it is observational in nature? Difficult to establish the timeline of exposure to disease outcometrials? “N=1”Advantages? Easy to manage? InexpensiveLimitations：? Findings difficult to be generalized to the whole population? Weakest evidence due to the number of the subject7、? Synthesis of evidence is completely dependent on:? The completeness of the literature search (unavailable for foreign studies)? The accuracy of evaluation·There are situations in which no answer can be found for the questions of interest in RCTs and database analyses.·There's the requirement of using less stringent information rather than “hard data”8、·Assessment of the intrinsic value of traditional medicine in society·Research and education·Political, economic, and social factorsUnit51、·Dis-ease refers to the imbalance arising from：? Continuous stress? Pain? Hardships·Disease is a health crisis ascribable to various dis-eases.·Prompting elimination of dis-eases can alleviate some diseases.2、·Wellness is a state involving every aspect of our being: body, mind and spirit.·Manifestations of a healthy person:? Energy and vitality? A certain zip in gait? A warm feeling of peace of heart seen through behavior3、·Constant messages, positive and negative，are sent to our mind about the health of our body.·Physical symptoms are suppressed by people who go through life on automatic pilot.·Being well equals to being disease- or illness-free in the minds of them.·They confused wellness with an absence of symptoms.4、·People's minds are infected by spin:? Half-truth? Fearful fictions? Blatant deceit: some as a form of self-deceit·Spin is a result of unconscious living.·The kind of falseness is pandemic.5·Our body intelligence is suppressed or dormant from a lack of use.·There are tremendous amount of stress on a daily basis.·Our bodies are easily ignored for years because of a lack of recreation time. ·Limiting, self-defeating and even self-destructive behaviors undermine our wellbeing and keep them from achieving our full potential.6·We grow more reluctant to take risks.·We lose the ability to feel and acknowledge our deepest feelings and the courage to speak our truth.·We continue to deny and repress our feelings to protect ourselves.·Fear, denial and disconnection from our bodies and feelings become an unconscious, self-protective habit, a kind of default response to life.7·A multi-faceted process:? Looking for roots of and resolutions for the issues in different dimensions? Building our wellness toolbox slowly? Picturing our whole state of being·Attention to the little stuff:? Examining our lives honestly and setting clear intentions to change? Striving to maintain a balance of our mind, body and spirit? Taking small steps in the way to perceive and resolve conflict8·Try to awaken and evolve in order to live more consciously.·Get in touch with our genuine feelings and emotions.·Come to terms with the toxic emotionsUnit61、In the past, most people died at home. But now, more and more people are caredin hospitals and nursing homes at their end of life, which of course brings a newset of questions to consider.2、·Sixty-four years old with a history of congestive heart failure·Deciding to do everything medically possible to extend his life·Availability of around-the-clock medical services and a full range of treatmentchoices, tests, and other medical care·Relaxed visiting hours, and personal items from home3、Availability of around-the-clock medical resources, including doctors, nurses, andfacility.4、·Taking on a job which is big physically, emotionally, and financially·Hiring a home nurse for additional help·Arranging for services (such as visiting nurses) and special equipment (like ahospital bed or bedside commode)5、·Health insurance·Planning by a professional, such as a hospital discharge plaimer or a social worker·Help from local governmental agencies·Doctor's supervision at home6、·Traditionally, it is only about symptom care.·Recently, it is a comprehensive approach to improving the quality of life for people who are living with potentially fatal diseases.7、·Stopping treatment specifically aimed at curing an illness equals discontinuing all treatment.·Choosing a hospice is a permanent decision.Unit71、·A dying patient·Decision whether to withdraw life-support machines and medication and startcomfort measures·The family's refusal to make any decision or withdraw any treatments2、·The doctor as exclusive decision-maker·The patient as participant with little say in the final choice3、·Respect for the patient, especially the patient s autonomy·Patient-centered care·The patient as decision-maker based on the information provided by the doctor4、·Patients are forced to make decisions they never want to.·Patients, at least a large majority of them, prefer their doctors to make final decisions.·Shifting responsibility of decision-making to patients will bring about more stress to patients and their families, especially when the best option for the patient is uncertain.5、Doctors are very much cautious about committing some kind of ethicaltransgression.6、·Shouldering responsibility together with the patient may be better than havingthe patient make decisions on their own.·Balancing between paternalism and respect for patients autonomy constitutes alarge part of medical practice.Unit81、·Research:An activity to test hypothesis, to permit conclusions to be drawn, and thereby to develop or contribute to generalizable knowledge·Practice:Interventions solely to enhance the well-being of an individual patient or client and that have a reasonable expectation of success·Blurred distinction:? Cooccurrence of research and practice like in research designed to evaluate a therapy? Notable departures from standard practice being called “experimental” withl”and “research” carelessly definedthe terms “experimenta2、·Autonomy：Individuals treated as autonomous agents .·Protection:Persons with diminished autonomy entitled to protection·A case in point:Prisoners involved in research3·“Do no harm” as the primary principle·Maximization of possible benefits and minimization of possible harms .·Balance between benefits and potential risks involved in every step of seedingthe benefits4、·“Do no harm” as a fundamental principle of medical ethics·Extension of it to the realm of research by Claude Bernard·Benefits and risks as a set “duet” in both medical practice and research 5、·Unreasonable denial of entitled benefit and unduly imposed burden：Enrolment of patients in new drug trial: Who should be enrolled and who should not?·Equal treatment of equals:Determining factors of equality: age, sex, severity of the condition, financial status, social status6、·Definition:The opportunity to choose what shall or shall not happen to them·Application:? A process rather than signing a written form? Adequate information as the premise? A well-informed decision as the expected result7、·Requirements for consent as entailed by the principle of respect for persons ·Risk/benefit assessment as entailed by the principle of beneficence ·More requirements of fairness as entailed by the principle of justice: ? At the individual level: fairness? At the social level: distinction between classes。

第八章：实验设计的例子(Experimental Design Examples)黄炽森引言在前几章我们介绍了关于测量工具的信度、效度及建立可接受的测量工具的步骤和所需的证据。

本章的目的是介绍与实验设计(Experimental Designs)相关的研究方法，我们会先重复实验设计的定义，然后简介实验设计要注意的几个重点，及针对实验设计的常用的统计分析工具，最后我们会讨论几个实验设计的研究例子。

实验设计的定义及要注意的重点在第三章中，我们曾指出实验(Experiment)和准实验(Quasi-Experiment)设计的定义：「真的实验，要符合两个条件。

第一个是可控制我们要研究的原因(即X；自变项；Independent variable)，或称为实验的情景(Experimental conditions)，例如我们在研究某一新报酬制度(X)对员工生产力(Y；即依变项；Dependent variable)的影响时，如果我们可以设计新的报酬制度及保留原来的报酬制度以作比较，这便是可控制要研究的原因。

第二个是能随机分派实验的对象(Random assignment)，在管理学的研究中，研究对象一般是个人，小组或整个机构。

用同一个例子，即某一新报酬制度(X)对员工生产力(Y)的影响，我们的研究对象便是员工(个人)，如果我们可以把员工完全随机地分派到新旧两个报酬制度之中，然后观察﹑测量及比较他们的生产力，这样才是真正的实验。

」「不过，在进行研究中，我们不一定能随机分派实验的对象，例如虽然我们可以设计新的报酬制度来与旧的比较，企业不一定容许我们把他的员工随机分派。

这种祗有控制实验情景，而没有随机分派实验对象的研究设计，我们称为准实验(Quasi-Experiment)，它提供了X与Y的共变及X先Y后的次序，但却不能完全排除其它也可能影响Y的因素，因此，在准实验的设计中，我们很多时会尽量考虑或甚至是测量了其它可能影响Y的因素(例如在进行研究前员工的生产力及他们的聪明才智)，以逻辑推理或统计分析的方法来排除这些因素的可能性。

a quasi-experimental study 概述及解释说明1. 引言1.1 概述本研究旨在探讨和解释一个准实验研究，即“a quasi-experimental study”。

准实验设计是一种研究方法，其允许研究者在没有完全随机分配的情况下进行干预和比较。

与纯实验设计相比，准实验设计更具可行性和实际意义，并被广泛应用于社会科学、心理学和教育领域等。

本文将提供对准实验研究的概述，解释其核心概念和方法，并介绍该领域的最新发展。

通过展示一个具体案例的细节和结果，我们将深入探讨这一研究方法在特定领域中的应用及其相关意义。

1.2 文章结构本文分为五个主要部分：引言、正文、结果与讨论、局限性与未来研究方向以及结论。

在引言部分，将介绍准实验研究的背景和意义，并说明文章结构、目的以及各部分内容。

紧接着，在正文中将详细介绍该准实验研究的设计、参与者选择以及数据收集和分析方法。

结果与讨论部分将对实验结果进行分析，并解释和讨论研究的发现。

随后，我们将探讨研究的局限性，并提出改进方向和未来的研究方向。

最后，在结论中总结主要发现，并展望该准实验研究对实践和理论的意义以及其应用前景。

1.3 目的本文旨在全面介绍准实验研究的概念、设计和方法，并通过一个具体案例来说明其应用。

我们希望读者能够了解准实验设计在社会科学领域中的重要性，以及如何运用该方法来得出有价值且可靠的研究结果。

同时，通过详细解释和分析该案例研究的结果，我们旨在引发读者对于准实验研究及其相关领域更深入思考和讨论。

最终，我们期待本文能为未来准实验设计的改进提供一些有益的指导和建议，并为进一步探索这一领域提供新的研究方向。

2. 正文:2.1 实验设计:本研究采用准实验设计，旨在探究某一特定变量对另一变量的影响。

通过准实验设计，我们可以观察到因果关系的存在与否，并提供初步证据支持该关系。

在本研究中，我们将引入一个介入或处理群体，并与控制群体进行比较，以评估介入对被观察指标的影响。

学术英语医学课后问题答案集团文件发布号：（9816-UATWW-MWUB-WUNN-INNUL-DQQTY-Unit11、Some factors that may lead to the complaint:·Neuron overload·Patients* high expectations·Mistrust and misunderstanding between the patient and the doctor 2、Mrs. Osorio’s condition:·A 56-year-old woman·Somewhat overweight·Reasonably well-controlled diabetes and hypertension·Cholesterol on the high side without any medications for it·Not enough exercises she should take·Her bones a little thin on her last DEXA scan3、 Good things:·Blood tests done·Glucose a little better·Her blood pressure a little better but not so great Bad things:·Cholesterol not so great·Her weight a little up·Her bones a little thin on her last DEXA scan44、The situation:·The author was in a moderate state of panic: juggling so many thoughts about Mrs. Osorio’s conditions and trying to resolve them all before the clock ran down.·Mrs. Osorio made a trivial request, not so important as compared to her conditions.·Mrs. Osorio seemed to care only about her “innocent —and completely justified —request”： the form signed by her doctor.·The doctor tried to or at least pretended to pay attention to the patient while completing documentation.5、Similarities:·In computer multitasking, a microprocessor actually performs only one task at a time. Like microprocessors, we human beings carft actually concentrate on two thoughts at the same exact time.Multitasking is just an illusion both in computers and human beings.Differences:·The concept of multitasking originated in computer science.·At best, human beings can juggle only a handful of thoughts in amultitasking manner, but computers can do much better.·The more thoughts human beings juggle, the less human beings are able to attune fully to any given thought, but computers can do much better.6、·7 medical issues to consider·5 separate thoughts, at least, for each issue·7 x 5 = 35 thoughts·10 patients that afternoon·35 x 10 = 350 thoughts·5 residents under the authors supervision·4 patients seen by each resident·10 thoughts, at least, generated from each patient·5 x 4 x 10 = anther 200 thoughts·350 + 200 = 550 thoughts to be handled in total·If the doctor does a good job juggling 98% of the time, thatstill leaves about 10 thoughts that might get lost in the process.7、Possible solutions:·Computer-generated reminders·Case managers·Ancillary services·The simplest solution: timeUnit21、The author implies:Peoples inadequate consciousness about the consequence of neglecting the re- emerging infectious diseases·Unjustifiability of peoples complacency about the prevention and control of the infectious diseases·Unfinished war against infectious diseases2、Victory declarations:·Surgeon General William Stewart's hyperbolic statement of closing “the book on infectious disease”.·A string of impressive victories incurred by antibiotics and vaccines·The thought that the war against infectious diseases was almost over What followed ever since:·Appearance of new diseases such as AIDS and Ebola·Comeback of the old afflictions:Diphtheria in the former Soviet UnionTB in urban centers like New York CityRising Group A streptococcal conditions like scarlet fever·The fear of a powerful new flu strain sweeping the world3、Elaborate on the joined battle:·WHO established a new division devoted to worldwide surveillance and control of emerging disease in October 1995.·CDC launched a prevention strategy in 1994.·Congress raised fund from $6.7 million in 1995 to $26 million in 1997.4、The borders are meaningless to pathogenic microbes, which cantravel from one country to another remote country in a very short time.5、TB:·Prisons and homeless shelters as ideal places for TB spread ·Emerging of drug-resistant strain or even multi-drug-resistant strain· A ride on the HIV w^on by attacking the immunocompromisedGroup A strep:·A change in virulence·Mutation in the exterior of the bacteriumFlu:Constant changes in its coat (surface antigens) and resultant changes in its level of virulence6、Examples:·Experiment in England is seeing the waning immunity because of no vaccination.·D u e to poor vaccination efforts, the diphtheria situation in the former Soviet Union is serious. 'The vaccination rates are dropping in some American cities, and it will lead to more diphtheria and whooping cough.7、The four areas of focus:·The need for surveillance·Updated science capable of dealing with discoveries in the field ·Appropriate prevention and control·Strong public health infrastructure8、The infectious diseases such as TB, flu, diphtheria and scarlet fever will never really go away, and the war against them will never end.Unit31、Terry's life before·She loved practicing Tae Kwon Do·She loved the surge of adrenaline that came with the controlled combat of tournaments.·She competed nationally, even won bronze medal in the trials for the Pan American Games.·She attended medical school, practiced as an internal medicine resident, and became an academic general internist.·She got married and got a son and a daughter.2、The symptoms of MS and autoimmune disease:·Loss of stamina and strength·Problems with balance·Bouts of horrific facial pain·Dips in visual acuity3、Terry did the following before she self-experimented:·She started injections.·She adopted many pharmacotherapies.·She began her own study of literature:She read articles on websites such as PubMed.She searched for articles testing new MS drugs in animal models.She turned to articles concerning neurodegeneration of all types —dementia， Parkinson's disease, Huntington's disease, and Lou Gehrig's disease.She relearned basic sciences such as cellular physiology, biochemistry, and neurophysiology.4、Approaches Terry mainly used:·Self-experimentation with various nutrients to slow neurodegeneration based on literature reports on animal models ·Self-experimentation with neuromuscular electrical stimulation which is not an approved treatment for MS·Online search to identify the sources of micronutrients and having a new diet·Reduction of food allergies and toxic load5、Cases mentioned in the text:·Increased mercury stores in the brains of people with dental fillings·High levels of the herbicide atrazine in private wells in Iowa ·The strong association between pesticide exposure and neurodegeneration·The association of single nucleotide polymorphisms involving metabolism of sulfur and/or B vitamins·Inefficient clearing of toxins6、With 70% to 90% of the risk for diabetes, heart disease, cancer,and autoimmunity being due to environmental factors other than the genes, we can take many health problems and the health care crisis under our control, for example, optimizing our nutrition and reducing our toxic load.Unit41、Two concepts:·Complementary medicine refers to the use of conventional therapies together with alternative treatments such as using acupuncture in addition to usual care to help lessen pain.Complementary and alternative medicine is shortened as CAM.·Alternative medicine refers to healing treatments that are not part of conventional therapies —like acupuncture, massage therapy, or herbal medicine. They are called so because people used to consider practices like these outside the mainstream.2·TCM does not require advanced, complicated, and in most cases, expensive facilities.·TCM employs needles, cups, coins, to mention but a few.·Most procedures and operations of TCM are noninvasive.·The substances used as medicine are raw herbs or abstracts from them, and they are indeed all natural, from nature.·TCM has been practiced as long as the Chinese history, so the proven and ensured.efficiency is·Ongoing research around the world on acupuncture, herbs, massage and Tai Chi have shed light on some of the theories and practices of TCM3、It may be used as an adjunct treatment, an alternative, or part of a comprehensive management program for a number of conditions: post-operative and chemotherapy induced nausea and vomiting, post-operative dental pain, addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma.4、A well-justified NO:·More intense research to uncover additional areas for the use of acupuncture·Higher adoption of acupuncture as a common therapeutic modality not only in treatment but also in prevention of disease and promotion of wellness·Exploration and perfection of innovative methods of acupuncture point stimulation with technological advancement·Improved understanding of neuroscience and other aspects of human physiology and function by basic research on acupuncture·Greater interest by stakeholders·An increasing number of physician acupuncturists5、·Appropriate uses of herbs depend on proper guidance:Proper TCM diagnosis of the zheng of the patientCorrect selection of the corresponding therapeutic strategies and principles that guide the choice of herbs and herbal formulas·Digression from either of the above guidence will lead to misuses of herbs, and will result in complications in patient6、·Randomized controlled trialsAdvantages:Elimination of the potential bias in the allocation of participants to the intervention group or control groupTendency to produce comparable groupsGuaranteed validity of statistical tests of significance Limitations:Difficulty in generalizing the results obtained from the selected sampling to the population as a wholeA poor choice for research where temporal factorsare an issueExtremely heavy resources, requiring very largesample groupsQuasi-experimentsAdvantages:Control group comparisons possibleReduced threats to external validity as naturalenvironments do not suffer the same problems ofartificiality as compared to a well-controlled laboratorysetting.Generalizations of the findings to be made about population since quasiexperiments are natural experiments Limitations：Potential for non-equivalent groups as quasi-experimentaldesigns do not use random sampling in constructingexperimental and control groups.Potential for low internal validity as a result of not using random sampling methods to construct the experimental and control groupsCohort studiesAdvantages:Clear indication of the temporal sequence between exposure and outcomeParticular use for evaluating the effects of rare or unusual exposureAbility to examine multiple outcomes of a single risk factorLimitations:Larger, longer, and more expensiveProne to certain types of biasNot practical for rare outcomesCase-control studiesAdvantages:The only feasible method in the case of rare diseases and those with long periods between exposure and outcomeTime and cost effective with relatively fewer subjects as compared to other observational methodsLimitations：Unable to provide the same level of evidence as randomized controlled trials as it is observational in natureDifficult to establish the timeline of exposure to disease outcome“N=1” trialsAdvantagesEasy to manageInexpensiveLimitations：Findings difficult to be generalized to the wholepopulationWeakest evidence due to the number of the subject7、Synthesis of evidence is completely dependent on:The completeness of the literature search (unavailable for foreign studies)The accuracy of evaluation·There are situations in which no answer can be found for the questions of interest in RCTs and database analyses.·There's the requirement of using less stringent information rather than “hard data”8、·Assessment of the intrinsic value of traditional medicine insociety·Research and education·Political, economic, and social factorsUnit51、·Dis-ease refers to the imbalance arising from：Continuous stressPainHardships·Disease is a health crisis ascribable to various dis-eases.·Prompting elimination of dis-eases can alleviate some diseases.2、·Wellness is a state involving every aspect of our being: body, mind and spirit.·Manifestations of a healthy person:Energy and vitalityA certain zip in gaitA warm feeling of peace of heart seen through behavior3、·Constant messages, positive and negative，are sent to our mind about the health of our body.·Physical symptoms are suppressed by people who go through life on automatic pilot.·Being well equals to being disease- or illness-free in the minds of them.·They confused wellness with an absence of symptoms.4、·People's minds are infected by spin:Half-truthFearful fictionsBlatant deceit: some as a form of self-deceit·Spin is a result of unconscious living.·The kind of falseness is pandemic.5·Our body intelligence is suppressed or dormant from a lack of use.·There are tremendous amount of stress on a daily basis.·Our bodies are easily ignored for years because of a lack of recreation time.·Limiting, self-defeating and even self-destructive behaviors undermine our wellbeing and keep them from achieving our full potential.6·We grow more reluctant to take risks.·We lose the ability to feel and acknowledge our deepest feelings and the courage to speak our truth.·We continue to deny and repress our feelings to protect ourselves.·Fear, denial and disconnection from our bodies and feelings become anunconscious, self-protective habit, a kind of default response to life.7·A multi-faceted process:Looking for roots of and resolutions for the issues in different dimensionsBuilding our wellness toolbox slowlyPicturing our whole state of being·Attention to the little stuff:Examining our lives honestly and setting clear intentions to changeStriving to maintain a balance of our mind, body and spiritTaking small steps in the way to perceive and resolve conflict8·Try to awaken and evolve in order to live more consciously.·Get in touch with our genuine feelings and emotions.·Come to terms with the toxic emotionsUnit61、In the past, most people died at home. But now, more and morepeople are cared in hospitals and nursing homes at their end of life, which of course brings a new set of questions to consider.2、·Sixty-four years old with a history of congestive heart failure ·Deciding to do everything medically possible to extend his life ·Availability of around-the-clock medical services and a full range of treatment choices, tests, and other medical care·Relaxed visiting hours, and personal items from home3、Availability of around-the-clock medical resources, includingdoctors, nurses, and facility.4、·Taking on a job which is big physically, emotionally, and financially·Hiring a home nurse for additional help·Arranging for services (such as visiting nurses) and special equipment (like a hospital bed or bedside commode)5、·Health insurance·Planning by a professional, such as a hospital discharge plaimer or a social worker·Help from local governmental agencies·Doctor's supervision at home6、·Traditionally, it is only about symptom care.·Recently, it is a comprehensive approach to improving the quality of life for people who are living with potentially fatal diseases.7、·Stopping treatment specifically aimed at curing an illness equals discontinuing all treatment.·Choosing a hospice is a permanent decision.Unit71、·A dying patient·Decision whether to withdraw life-support machines and medication and start comfort measures·The family's refusal to make any decision or withdraw any treatments2、·The doctor as exclusive decision-maker·The patient as participant with little say in the final choice3、·Respect for the patient, especially the patient s autonomy·Patient-centered care·The patient as decision-maker based on the information provided by the doctor4、·Patients are forced to make decisions they never want to.·Patients, at least a large majority of them, prefer their doctors to make final decisions.·Shifting responsibility of decision-making to patients will bring about more stress to patients and their families, especially when the best option for the patient is uncertain.5、Doctors are very much cautious about committing some kind ofethical transgression.6、·Shouldering responsibility together with the patient may be better than having the patient make decisions on their own.·Balancing between paternalism and respect for patients autonomy constitutes a large part of medical practice.Unit81、·Research:An activity to test hypothesis, to permit conclusions to be drawn, and thereby to develop or contribute to generalizable knowledge·Practice:Interventions solely to enhance the well-being of an individual patient or client and that have a reasonable expectation of success·Blurred distinction:Cooccurrence of research and practice like in research designed to evaluate a therapyNotable departures from standard practice being called “experimental” with the terms “experimenta l”and “research”carelessly defined2、·Autonomy：Individuals treated as autonomous agents .·Protection:Persons with diminished autonomy entitled to protection·A case in point:Prisoners involved in research3·“Do no harm” as the primary principle·Maximization of possible benefits and minimization of possible harms .·Balance between benefits and potential risks involved in every step of seeding the benefits4、·“Do no harm” as a fundamental principle of medical ethics ·Extension of it to the realm of research by Claude Bernard ·Benefits and risks as a set “duet” in both medical practice and research5、·Unreasonable denial of entitled benefit and unduly imposed burden：Enrolment of patients in new drug trial: Who should be enrolled and who should not·Equal treatment of equals:Determining factors of equality: age, sex, severity of the condition, financial status, social status6、·Definition:The opportunity to choose what shall or shall not happen to them ·Application:A process rather than signing a written formAdequate information as the premiseA well-informed decision as the expected result7、·Requirements for consent as entailed by the principle of respect for persons·Risk/benefit assessment as entailed by the principle of beneficence·More requirements of fairness as entailed by the principle of justice:At the individual level: fairnessAt the social level: distinction between classes。

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randomly.Instead, quasi-experiments use a combination of design features,practical logic,and statistical analysis to show that the presumed cause is likely to be responsible for the observed effect,and other causes are not.The term nonrandomized experiment is synonymous with quasi-experiment;and the terms observational study and nonexperimental design often include quasi-experiments as a subset.This article discusses the need for quasi-experimentation,describes the kinds of designs that fall into this class of methods,reviews the intellectual and practical history of these designs,and notes important current developments.1.The Need for Quasi-experimentationGiven the desirable properties of randomized experi-ments,one might question why quasi-experiments are needed.When properly implemented,randomized experiments yield unbiased estimates of treatment effects,accompanied by known probabilities of error in identifying effect size.Quasi-experimental designs do not have these properties.Yet quasi-experiments are necessary in the arsenal of science because it is not always possible to randomize.Ethical constraints may preclude withholding treatment from needy people based on chance,those who administer treatment may refuse to honor randomization,or questions about program effects may arise after a treatment was already implemented so that randomization is im-possible.Consequently,the use of quasi-experimental designs is frequent and inevitable in practice.2.Kinds of Quasi-experimental DesignsThe range of quasi-experimental designs is large, including but not limited to:(a)Nonequivalent control group designs in which the outcomes of two or more treatment or comparison conditions are studied but the experimenter does not control assignment to conditions;(b)Interrupted time series designs in which many consecutive observations over time(proto-typically100)are available on an outcome,and treatment is introduced in the midst of those observa-tions to demonstrate its impact on the outcome through a discontinuity in the time series after treat-ment;(c)Regression discontinuity designs in which the experimenter uses a cutoffscore on a measured variable to determine eligibility for treatment,and12655Quasi-Experimental Designsan effect is observed if the regression line(of the assignment variable on outcome)for the treatment group is discontinuous from that of the comparison group at the cutoffscore;(d)Single-case designs in which one participant is repeatedly observed over time (usually on fewer occasions than in time series)while the scheduling and dose of treatment are manipulated to demonstrate that treatment controls outcome.In the preceding designs,treatment is manipulated, and outcome is then observed.Two other classes of designs are sometimes included as quasi-experiments, even though the presumed cause is not manipulated (and often not even manipulable)prior to observing the outcome.In(e)case–control designs,a group with an outcome of interest is compared to a group without that outcome to see if they differ retrospectively in exposure to possible causes in the past;and in(f) correlational designs,observations on possible treat-ments and outcomes are observed simultaneously, often with a survey,to see if they are related.Because these designs do not ensure that cause precedes effect, as it must logically do,they usually yield more equivocal causal inferences.3.The History of Quasi-experimental Designs Quasi-experimental designs have an even longer his-tory than randomized experiments.For example, around1,850epidemiologists used case–control meth-ods to identify contaminated water supplies as the cause of cholera in London(Schlesselman1982),and in1898,Triplett used a nonequivalent control group design to show that the presence of audience and competitors improved the performance of bicyclists. In fact,nearly all experiments conducted prior to Fisher’s work were quasi-experiments.However,it was not until1963that the term quasi-experiment was coined by Campbell and Stanley (1963)to describe this class of designs.Campbell and his colleagues(Cook and Campbell1979,Shadish et al.in press)extended the theory and practice of these designs in three ways.First,they described a large number of these designs,including variations of the designs described above.For example,some quasi-experimental designs are inherently longitudinal(e.g., time series,single case designs),observing participants over time,but other designs can be made longitudinal by adding more observations before or after treatment. Similarly,more than one treatment or control group can be used,and the designs can be combined,as when adding a nonequivalent control group to a time series. Second,Campbell developed a method to evaluate the quality of causal inferences resulting from quasi-experimental designs—a validity typology that was elaborated in Cook and Campbell(1979).The ty-pology includes four validity types and threats to validity for each type.Threats are common reasons why researchers may be wrong about the causal inferences they draw.Statistical conclusion validity concerns inferences about whether and how much presumed cause and effect co-vary;examples of threats to statistical conclusion validity include low statistical power,violated assumptions of statistical tests,and inaccurate effect size estimates.Internal validity con-cerns inferences that observed co-variation is due to the presumed treatment causing the presumed out-come;examples include history(extraneous events that could also cause the effect),maturation(natural growth processes that could cause an observed change),and selection(differences between groups before treatment that may cause differences after treatment).Construct validity concerns inferences about higher-order constructs that research operations represent;threats include experimenter expectancy effects whereby participants react to what they believe the experimenter wants to observe rather than to the intended treatment,and mono-operation bias in which researchers use only one measure that reflects a construct imperfectly or incorrectly.External validity concerns inferences about generalizing a causal relationship over variations in units,treatments, observations,settings,and times;threats include interactions of the treatment with other features of the design that produce unique effects that would not otherwise be observed.Third,Campbell’s theory emphasized addressing threats to validity using design features—things that a researcher can manipulate to prevent a threat from occurring or to diagnose its presence and potential impact on study results(see Table1).For example, suppose maturation(normal development)is an an-ticipated threat to validity because it could cause a pretest–post-test change like that attributed to the treatment.The inclusion of several consecutive pre-tests before treatment can indicate whether the rate of maturation before treatment is similar to the rate of change from during and after treatment.If it is similar, maturation is a threat.All quasi-experiments are combinations of these design features,thoughtfully chosen to diagnose or rule out threats to validity in a particular context.Conversely,Campbell was skep-tical about the more difficult task of trying to adjust threats statistically after they have already occurred. The reason is that statistical adjustments require making assumptions,the validity of which are usually impossible to test,and some of which are dubious (e.g.,that the selection model is known fully,or that the functional form of errors is known).Other scholars during this time were also interested in causal inferences in quasi-experiments,such as Cochran(1965)in statistics,Heckman(1979)in economics,and Hill(1953)in epidemiology.However, Campbell’s work was unique for its extensive emphasis on design rather than statistical analysis,for its theory of how to evaluate causal inferences,and for its sustained development of quasi-experimental theory12656Quasi-Experimental DesignsTable1Design elements used in constructing quasi-experimentsAssignment(Control of assignment strategies to increase group comparability)Cutoff-based assignment.Controlled assignment to conditions based solely on one or more fully measured covariates.This can yield an unbiased effect estimateOther nonrandom assignment.Various forms of‘haphazard’assignment that sometimes approximate randomization(e.g.,alternating assignment in a two condition quasi-experiment whereby every other unit is assigned to one condition,etc.)Matching and stratifying.Efforts to create groups equivalent on observed covariates in ways that are stable,do not lead to regression artifacts,and are correlated with the outcome.Preference is for pretreatment measures of the outcome itselfMeasurement(Use of measures to learn whether threats to causal inference actually operate)Post-test observationsNonequi alent dependent ariables.Measures that are not sensitive to the causal forces of the treatment,but are sensitive to all or most of the confounding causal forces that might lead to false conclusions about treatment effects(if such measures show no effect,but the outcome measures do show an effect,the causal inference is bolstered because it is less likely due to the confounds)Multiple substanti e ed to assess whether the treatment affects a complex pattern of theoretically predicted outcomesPretest observationsSingle pretest.A pretreatment measure on the outcome variable,useful to help diagnose selection biasRetrospecti e pretest.Reconstructed pretests when actual pretests are not feasible—by itself,a very weak design feature,but sometimes better than nothingProxy pretest.When a true pretest is not feasible,a pretest on a variable correlated with the outcome—also often weak by itselfMultiple pretest time points on the outcome.Helps reveal pretreatment trends or regression artifacts that might complicate causal inferencePretests on independent samples.When a pretest is not feasible on the treated sample,one is obtained from a randomly equivalent sampleComplex predictions such as predicted interactions.Successfully predicted interactions lend support to causal inference because alternative explanations become less plausibleMeasurement of threats to internal alidity.Help diagnose the presence of specific threats to the inference that A caused B such as whether units actively sought out additional treatments outside the experimentComparison groups(Selecting comparisons that are‘less nonequivalent’or that bracket the treatment group at the pretest(s))Single nonequi alent pared to studies without control groups,using a nonequivalent control group helps identify many plausible threats to validityMultiple nonequi alent groups.Serve several functions.For instance,groups are selected that are as similar as possible to the treated group but at least one outperforms it initially and at least one underperforms it,thus bracketing the treated groupparison groups chosen from the same institution in a different cycle(e.g.,sibling controls in families or last year’s students in schools)Internal( s.external)controls.Plausibly chosen from within the same population(e.g.,within the same school rather than from a different school)Treatment(Manipulations of the treatment to demonstrate that treatment variability affects outcome variability) Remo ed treatments.Showing an effect diminishes if treatment is removedRepeated treatments.Reintroduces treatments after they have been removed from some group—common in laboratory sciences or where treatments have short-term effectsSwitching replications.Reverses treatment and control group roles so that one group is the control while the other receives treatment,but the controls receive treatment later while the original treatment group receives no further treatment or has treatment removedRe ersed treatments.Provides a conceptually similar treatment that reverses an effect—e.g.,reducing access to a computer for some students but increasing access for othersDosage ariation.Demonstrates that outcome responds systematically to different levels of treatmentand method over four decades.Both the theory and the methods he outlined were widely adopted in practice during the last half of the twentieth century,and his terms like internal and external validity became so much a part of the scientific lexicon that today they are often used without reference to Campbell.12657Quasi-Experimental Designs4.Contemporary Research aboutQuasi-experimental Design4.1Statistics and Quasi-experimental Design Although work on the statistical analysis of quasi-experimental designs deserves separate treatment, several contemporary developments deserve mention here.One is the work of statisticians such as Paul Holland,Paul Rosenbaum,and Donald Rubin on statistical models for quasi-experimental designs(e.g., Rosenbaum1995).They emphasize the need to measure what would have happened to treatment participants without treatment(the counterfactual), and focus on statistics that can improve estimates of the counterfactual without randomization.A central method uses propensity scores,a predicted probability of group membership obtained from logistic regres-sion of actual group membership on predictors of outcome or of how participants got into treatment. Matching,stratifying,or co-varying on the propensity score can balance nonequivalent groups on those predictors,but they cannot balance groups for un-observed variables,so hidden bias may remain.Hence these statisticians have developed sensitivity analyses to measure how much hidden bias would be necessary to change an effect in important ways.Both propensity scores and sensitivity analysis are promising develop-ments warranting wider exploration in quasi-experi-mental designs.A second statistical development has been pursued mostly by economists,especially James Heckman and his colleagues,called selection bias modeling(Winship and Mare1992).The aim is to remove hidden bias in effect estimates from quasi-experiments by modeling the selection process.In principle the statistical models are exciting,but in practice they have been less successful.A series of studies in the1980s and1990s found that effect estimates from selection bias models did not match results from randomized experiments. Economists responded with various adjustments to these models,and proposed tests for their appropriate application,but so far results remain discouraging. Most recently,some economists have improved results by combining selection bias models with propensity scores.Although selection bias models cannot yet be recommended for widespread adoption,this topic continues to develop rapidly and serious scholars must attend to it.For example,other economists have developed useful econometrically based sensitivity analyses.Along with the incorporation of propensity scores,this may promise a future convergence in statistical and econometric literatures.A third development is the use of structural equation modeling(SEM)to study causal relationships in quasi-experiments,but this effort has also been only partly successful(Bollen1989).The capacity of SEM to model latent variables can sometimes reduce problems of bias caused by unreliability of measurement,but its capacity to generate unbiased effect estimates is hamstrung by the same lack of knowledge of selection that thwarts selection bias models.4.2The Empirical Program of Quasi-experimental DesignMany features of quasi-experimentation pertain to matters of empirical fact that cannot be resolved by statistical theory or logical analysis.For these features, a theory of quasi-experimental design benefits from empirical research about these facts.Shadish(2000) has presented an extended discussion of what such an empirical program of quasi-experimentation might look like,including studies of questions like the following:(a)Can quasi-experiments yield accurate effect estimates,and if so,under what conditions?(b)Which threats to validity actually occur in practice(e.g.,pretest sensitization,experimenter ex-pectancy effects),and if so,under what conditions?(c)Do the design features in Table1improve causal inference when applied to quasi-experimental design, and if so,under what conditions?Some of this empirical research has already been conducted(see Shadish2000,for examples).The methodologies used to investigate such questions are eclectic,including case studies,surveys,literature reviews(quantitative and qualitative),and experi-ments themselves.Until very recently,however,these studies have generally not been systematically used to critique and improve quasi-experimental theory.5.ConclusionThree important factors have converged at the end of the twentieth century to create the conditions under which the development of better quasi-experimen-tation may be possible.First,over30years of practical experience with quasi-experimental designs have pro-vided a database from which we can conduct empirical studies of the theory.Second,after decades of focus on randomized designs,statisticians and economists have turned their attention to improving quasi-experimen-tal designs.Third,the computer revolution provided both theorists and practitioners with increased ca-pacity to invent and use more sophisticated and computationally intense methods for improving quasi-experiments.Each in their own way,these three factors have taken us several steps closer to answering that great unanswered question with which this article began.See also:Campbell,Donald Thomas(1916–96); Comparative Studies:Method and Design;Exper-imental Design:Overview;Experimental Design:12658Quasi-Experimental DesignsRandomization and Social Experiments;Experi-mentation in Psychology,History of;Panel Surveys: Uses and ApplicationsBibliographyBollen K A1989Structural Equations with Latent Variables. 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Annual Re iew of Sociology18:327–50W.R.ShadishQueer Theory‘Queer theory’is a notoriously unstable phrase,and one much in contention.As a new theoretical move-ment with equally new political counterparts,it is in constantflux and development,and is charac-terized more by what it challenges and contests than by what it offers in the shape of a unified social theory. Drawing on the work of theorists such as Eve Sedgwick and Judith Butler,queer theory‘describes those gestures or analytical models which dramatise incoherencies in the allegedly stable relations between chromosomal sex,gender and sexual desire(Jagose 1996).In this sense,queer theory is a challenge to the ‘obvious categories(man,woman,latina,jew,butch, femme),oppositions(man vs.woman,heterosexual vs. homosexual),or equations(gender l sex)upon which conventional notions of sexuality and identity rely’(Hennessy1993).Queer theory argues instead that sexual desire and sexual practices are not reducible or explicable solely in terms of identity categories,such as gender,race,class,or sexual orientation.It is radically anti-essentialist,in that it challenges a notion of homosexuality as intrinsic,fixed,innate,and univer-sally present across time and space.Queer theorists reject any mode of thought that relies on a conception of identity as unified and self-evident(e.g.,I have sex with people of the opposite sex,therefore I must be heterosexual),and instead demonstrate that desires,sexual practices,and gen-dered identities are performances and enactments, rather than expressions of‘true’subjectivity.Hetero-sexuality is therefore challenged by queer theory not simply as a‘hegemonic’mode of identity,but as a false claim to unity and coherence that is constantly undermined by the incoherencies of sex and gender, incoherencies that the queer analytic hopes to expose and celebrate.1.Intellectual OriginsIn the broadest sense,queer theory emerged in what might be called the postmodern moment,when in-tellectual unease with unitary and cohesive frame-works of knowing reached a fever pitch.While impossible to summarize here,queer theory’s alle-giance to postmodern and\or poststructural modes of thought can be traced in its challenge to the notion of unitary identity(as in‘gay’or‘straight’),its refusal to understand sexuality through a singular and unified lens(homosexual desire,feminist theory,gender),a rejection of binary models(gay\straight,man\ woman,biological\social,real\constructed),and a more generic critique of identity-based theories and politics that,according to poststructuralist accounts, invariably reproduce the very conditions of repression they desire to challenge.For example,the term‘gay’or ‘homosexual’might be critiqued as a(fictional)cat-egory that shores up the binary opposition between ‘gay’and‘straight’that is itself part of the repressive logic of identity.To claim‘gayness’is therefore not simply or solely an act of self-revelation but is also a way of corralling sexuality within the framework of a category that only appears coherent but that,when opened up,reveals its instability(e.g.,Am I still gay if I sleep with a person of the opposite sex?Or if I sleep with those of the same sex but only in certain conditions and in certain ways?Or if my self-under-standing is of myself as‘straight?’).Queer theory,in that sense,has developed within and through the deconstructive impulse of poststructuralism,chal-lenging assertions of unitary identity and necessary linkages(between,say,sexual desire and gender orientation)and arguing instead for a more pro-visional,contingent,andfluid conception of the‘queer’in contemporary culture.While queer theory emerges as coterminous with postmodern impulses,it also traces its intellectual origins in lesbian\gay studies and feminist theory even12659Queer TheoryCopyright#2001Elsevier Science Ltd.All rights reserved.International Encyclopedia of the Social&Behavioral Sciences ISBN:0-08-043076-7。