Ch 4: Research Methods
Key Terms
hypothesis: “…Educated guess or statement to be tested by research.”
research design: “…Plan of experimentation used to test a hypothesis.”
dependent variable: “…In an experimental study, the phenomenon that is measured and expected to be influenced (compare with independent variable).”
independent variable: “…Phenomenon manipulated by the experimenter in a study and expected to influence the dependent variable.”
internal validity: “…Extent to which the results of a study can be attributed to the independent variable after confounding alternative explanations have been ruled out.”
external validity: “…Extent to which research findings generalize, or apply, to people and settings not involved in the study.”
testability: “…Ability of a hypothesis, for example, to be subjected to scientific scrutiny and to be accepted or rejected, a necessary condition for the hypothesis to be useful.”
confound: “…Any factor occurring in a study that makes the results uninterpretable because its effects cannot be separated from those of the variables being studied.”
confounding variable: “…Variable in a research study that was not part of the intended design and that may contribute to changes in the dependent variable.”
control group: “…Group of individuals in a study who are similar to the experimental subjects in every way but are not exposed to the treatment received by the experimental group. Their presence allows for a comparison of the differential effects of the treatment.”
randomization: “…Method for placing individuals into research groups that assures each an equal chance of being assigned to any group, thus eliminating any systematic differences across groups.”
analogue models: “…Approach to research that employs subjects who are similar to clinical clients, allowing replication of a clinical problem under controlled conditions.”
generalizability: “…Extent to which research results apply to a range of individuals not included in the study.”
statistical significance: “…Probability that obtaining the observed research findings merely by chance is small.”
clinical significance: “…Degree to which research findings have useful and meaningful applications to real problems.”
effect size: “…Statistical measure that shows the amount of difference among the members of a group in a clinical study.”
patient uniformity myth: “…Tendency to consider all members of a category as more similar than they are, ignoring their individual differences.”
case study method: “…Research procedure in which a single person or small group is studied in detail. The method does not allow conclusions about cause-and-effect relationships, and findings can be generalized only with great caution (contrast with single-case experimental design).”
correlation: “…Degree to which two variables are associated. In a positive correlation, the two variables increase or decrease together. In a negative correlation, one variable decreases as the other increases.”
positive correlation: “…Association between two variables in which one increases as the other increases.”
correlation coefficient: “…Computed statistic reflecting the strength and direction of any association between two variables. It can range from −1.00 through 0.00 (indicating no association) to +1.00, with the absolute value indicating the strength and the sign reflecting the direction.”
negative correlation: “…Association between two variables in which one increases as the other decreases.”
directionality: “…Possibility that when two variables, A and B, are correlated variable A causes variable B or variable B causes variable A.”
epidemiology: “…A psychopathology research method examining the prevalence, distribution, and consequences of disorders in populations.”
experiment: “…Research method that can establish causation by manipulating the variables in question and controlling for alternative explanations of any observed effects.”
placebo effect: “…Behavior change resulting from the person’s expectation of change rather than from the experimental manipulation itself.”
placebo control groups: “…In an outcome experiment, a control group that does not receive the experimental manipulation but is given a similar procedure with an identical expectation of change, allowing the researcher to assess any placebo effect.”
double-blind control: “…Procedure in outcome studies that prevents bias by ensuring that neither the subjects nor the providers of the experimental treatment know who is receiving treatment and who is receiving placebo.”
comparative treatment research: “…Outcome research that contrasts two or more treatment methods to determine which is most effective.”
single-case experimental designs: “…Research tactic in which an independent variable is manipulated for a single individual, allowing cause-and-effect conclusions but with limited generalizability (contrast with case study method).”
repeated measurement: “…When responses are measured on more than two occasions (not just before and after intervention) to assess trends.”
variability: “…Degree of change in a phenomenon over time.”
trend: “…Direction of change of a behavior or behaviors (for example, increasing or decreasing).”
level: “…Degree of behavior change with different interventions (for example, high or low).”
withdrawal design: “…Removing a treatment to note whether it has been effective. In single-case experimental designs, a behavior is measured (baseline), an independent variable is introduced (intervention), and then the intervention is withdrawn. Because the behavior continues to be measured throughout (repeated measurement), any effects of the intervention can be noted. Also called reversal design.”
baseline: “…Measured rate of a behavior before introduction of an intervention that allows comparison and assessment of the effects of the intervention.”
multiple baseline: “…A single-case experimental design in which measures are taken on two or more behaviors or on a single behavior in two or more situations. A particular intervention is introduced for each at different times. If behavior change is coincident with each introduction, this is strong evidence the intervention caused the change.”
phenotypes: “…Observable characteristics or behaviors of an individual.”
genotypes: “…Specific genetic makeup of an individual.”
human genome project: “…Ongoing scientific attempt to develop a comprehensive map of all human genes.”
endophenotypes: “…Genetic mechanisms that contribute to the underlying problems causing the symptoms and difficulties experienced by people with psychological disorders.”
family studies: “…Genetic studies that examine patterns of traits and behaviors among relatives.”
proband: “…In genetics research, the individual displaying the trait or characteristic being studied.”
adoption studies: “…In genetics research, the study of first-degree relatives reared in different families and environments. If they share common characteristics, such as a disorder, this finding suggests that those characteristics have a genetic component.”
twin studies: “…In genetics research, the comparison of twins with unrelated or less closely related individuals. If twins, particularly monozygotic twins who share identical genotypes, share common characteristics such as a disorder, even if they were reared in different environments, this is strong evidence of genetic involvement in those characteristics.”
genetic linkage analysis: “…Study that seeks to match the inheritance pattern of a disorder to that of a genetic marker. This helps researchers establish the location of the gene responsible for the disorder.”
genetic markers: “…Inherited characteristic for which the chromosomal location of the responsible gene is known.”
association studies: “…Research strategies for comparing genetic markers in groups of people with and without a particular disorder.”
cross-sectional design: “…Methodology to examine a characteristic by comparing individuals of different ages (contrast with longitudinal design).”
cohorts: “…Participants in each age group of a study with a cross-sectional design.”
cohort effect: “…Observation that people of different age groups differ in their values and experiences.”
retrospective information: “…Literally “the view back”; data collected by examining records or recollections of the past. It is limited by the accuracy, validity, and thoroughness of the sources.”
longitudinal designs: “…Systematic study of changes in the same individual or group examined over time (contrast with cross-sectional design).”
cross-generational effect: “…Limit on the generalizability of longitudinal research because the group under study may differ from others in culture and experience.”
sequential design: “…Combination of the cross-sectional and longitudinal designs involving repeated study of different cohorts over time.”
informed consent: “…Ethical requirement whereby research subjects agree to participate in a study only after they receive full disclosure about the nature of the study and their own role in it.”
Notes from Text
4-1 Examining Psychopathology
use scientific method
complex because biological and psychological
mind/brain hard to study
4-1a: Important Concepts
What causes the problem? Why do people behave abnormally (etiology)? How do we help them
4-1b: Basic Components of a Research Study
Science!!
Hypothesis → research design + what/who you are measuring
need internal validity and external validity
most of us seem to want to ask “why?” and to make sense/understand the world around us
make educated guess
“Once a scientist decides what to study, the next step is to put it in words that are unambiguous and in a form that is testable.”
testability is very important
also need to specify dependent and independent variables
need to look out for confounds that affect results, especially between groups
“Scientists use many strategies to ensure internal validity in their studies, three of which we discuss here: control groups, randomization, and analogue models.”
self-selection can affect study results
“Analogue models create in the controlled conditions of the laboratory aspects that are comparable (analogous) to the phenomenon under study…”
internal and external validity fight
want control, but also want genralized
4-1c: Statistical versus Clinical Significance
“In psychological research, statistical significance typically means that the probability of obtaining the observed effect by chance is small.”
“The difficulty is in the distinction between statistical significance (a mathematical calculation about the difference between groups) and clinical significance (whether or not the difference was meaningful for those affected).”
effect size helps
“The late behavioral scientist Montrose Wolf (1978) advocated the assessment of what he called social validity. This technique involves obtaining input from the person being treated, as well as from significant others, about the importance of the changes that have occurred.”
4-1d: The “Average” Client
see the individual, don’t make broad inaccurate generalizations
“on average” people get better … but there were people who didn’t
4-2: Types of Research Methods
4-2a: Studying Individual Cases
how does one explore a possible new disorder? case study method is a good option
look at one or more individuals/cases
does not use the scientific method
relies on clinical observations
little focus on internal validity or confounds
coincidences may confound
“Researchers in cognitive psychology point out that the public and researchers themselves are often, unfortunately, more highly influenced by dramatic accounts than by scientific evidence…”
4-2b: Research by Correlation
do variables relate?
“Unlike experimental designs, which involve manipulating or changing conditions, correlational designs are used to study phenomena just as they occur. The result of a correlational study—whether variables occur together—is important to the ongoing search for knowledge about psychopathology.”
correlation does not imply causation
A → B? B → A? Other variables?
Epidemiological Research
tracking a disorder in a population to better understand it
“…prevalence, the number of people with a disorder at any one time…”
“…incidence of a disorder, the estimated number of new cases during a specific period…”
“Like other types of correlational research, epidemiological research can’t tell us conclusively what causes a particular phenomenon.”
4-2c: Research by Experiment
manipulate variables to identify causality
“However, because we are never 100% confident that our experiments are internally valid—that no other explanations are possible—we must be cautious about interpreting our results.”
Group Experimental Designs
researchers change IV to see changes in groups
change/manipulation in IV may not occur naturally
“A clinical trial is an experiment used to determine the effectiveness and safety of a treatment or treatments. The term clinical trial implies a level of formality with regard to how it is conducted. As a result, a clinical trial is not a design by itself but rather a method of evaluation that follows a number of generally accepted rules.”
“…randomized clinical trials, which are experiments that employ randomization of participants into each experimental group. Another subset of clinical trials is controlled clinical trials, which are used to describe experiments that rely on control conditions to be used for comparison purposes.”
“…uses both randomization and one or more control conditions, is referred to as a randomized controlled trial.”
Control Groups
same as experimental groups EXCEPT no IV
“Using a control group allows the researchers to see that their treatment did help the treated participants keep their sleep time from decreasing further. Ideally, a control group is nearly identical to the treatment group in such factors as age, gender, socioeconomic backgrounds, and the problems they are reporting.”
control groups often experience placebo effect or nocebo effect
placebo control groups thing they get treatment
placebo + treatment = results
double-blind control “…eliminates the possibility that an investigator might bias the outcome.”
Comparative Treatment Research
compare different treatments
“Process research focuses on the mechanisms responsible for behavior change…”
what is causing the changes? why?
target helpful elements and get rid of not helpful ones
“…treatment process involves finding out why or how your treatment works. In contrast, treatment outcome involves finding out what changes occur after treatment.”
4-2d: Single-Case Experimental Designs
B. F. Skinner
study people in various controlled conditions
know a lot about 1 > > know a little about many
individual psychopathoplogy
Repeated Measurements: measure behavior multiple times before changing IV to see any changes/trends
identify variability day to day changes; identify trends
Withdrawal Designs
stop treatment (IV) and see what happens
3 parts: identify baseline, then change IV and see what happens, then remove IV and see what happens (“return to baseline“)
“How is this design different from a case study? An important difference is that the change in treatment is designed specifically to show whether treatment caused the changes in behavior.”
removing IV not always good idea/ethical/possible
“Drug holidays are periods when the medication is withdrawn so that clinicians can determine whether it is responsible for the treatment effects.”
Multiple Baseline : “Rather than stopping the intervention to see whether it is effective, the researcher starts treatment at different times across settings (home versus school), behaviors (yelling at spouse/partner or boss), or people.”
helps with internal validity
one beh, diff settings … or … two beh, one setting
Single case has external validity concerns bc it can’t be generalized
4-3: Genetics and Behavior across Time and Cultures
take into account genetics, behavior, and change over time due to culture
Studying Genetics
how do genes play a role?
phenotypes and genotypes
we know more about phenotypes for psychological disorders
now also looking at endophenotyopes: “…the genetic mechanisms that ultimately contribute to the underlying problems causing the symptoms and difficulties experienced by people with psychological disorders…”
basic genetic epidemiology, advanced genetic epidemiology, gene finding, and molecular genetics
Family Studies
look at family context
direct (first-degree) relatives are more likely to have genes
problem: people live together and emotions are “contagious”
Adoption Studies
separate nature vs. nurture
find people who were adopted that have disorder and find their first-degree relatives
Twin Studies
“…identical (monozygotic) twins (…). These twins not only look a lot alike but also have identical genes. Some changes do occur in chemical markers (called epigenetic markers) in the womb, which explains the subtle differences even in identical twins…”
“Fraternal (dizygotic) twins, on the other hand, come from different eggs and have only about 50% of their genes in common, as do all first-degree relatives.”
can infer how genes relate to different things vs how people were raised
Genetic Linkage Analysis and Association Studies
study disorder and other inherited traits at the same time
locate genetic markers that are close together
GLAs hard to replicate
“Whereas linkage studies compare markers in a large group of people with a particular disorder, association studies compare such people to people without the disorder. If certain markers occur significantly more often in the people with the disorder, it is assumed the markers are close to the genes involved with the disorder.”
4-3a: Studying Behavior over Time
helps to know how thing will change to determine treatment options
understanding developmental changes provide insight; changes may develop over time
“Prospective studies (which record changes over time as they occur)…”
“retrospective studies (which ask people to remember what happened in the past…).”
Prevention Research
prevent problems or slow onset
“These different methods can be viewed in four broad categories: positive development strategies (health promotion), universal prevention strategies, selective prevention strategies, and indicated prevention strategies…”
“Health promotion or positive development strategies involve efforts to blanket entire populations of people—even those who may not be at risk—to prevent later problems and promote protective behaviors.”
“Universal prevention strategies focus on entire populations and target certain specific risk factors (for example, behavior problems in classrooms in low-income communities) without focusing on specific individuals.”
“The third approach to prevention intervention—selective prevention—specifically targets whole groups at risk (for example, children who have parents who have died) and designs specific interventions aimed at helping them avoid future problems.”
“Finally, indicated prevention is a strategy for those individuals who are beginning to show signs of problems (for example, depressive symptoms) but do not yet have a psychological disorder.”
Cross-Sectional Designs
compare different age groups (cohorts)
members of each cohort may have different life experiences as well as being in different developmental phases (cohort effect)
preferred for studying things over time that are unlikely to be influenced by cultural life experiences
doesn’t look at individuals
Longitudinal Designs
pick a group of people and follow/assess them over time
no cohort effect problems
Studying Behavior across Cultures
miss things when we only study one culture
Rn we have a very ethnocentric Western POV
sometimes researchers treat the culture as the treatment/IV
different cultures may describe the same illness differently, or view different things as abnormal/normal, or even have different views on treatments
4-3b: Power of a Program of Research
research studies don’t always one study that can answer it. instead multiple studies can be done (program of research)
often one study → findings → new questions → new study etc….
4-3c: Replication
scientists never really believe something is true. show us multiple times
replicate replicate replicate
replicating results multiple times → increased confidence in results
4-3d: Research Ethics
ethical considerations have to be made when providing, delaying, or withdrawing treatments
informed consent from participants
“In studies using some form of treatment delay or withdrawal, the participant is told why it will occur and the risks and benefits, and permission to proceed is then obtained. In placebo control studies, participants are told they may not receive an active treatment (all participants are blind to or unaware of which group they are placed in), but they are usually given the option of receiving treatment after the study ends.”
“True informed consent is at times elusive. The basic components are competence, voluntarism, full information, and comprehension on the part of the participant…”
must consent
must not be coerced (or volunteer)
must have all the info
must understand what will be asked of them
can be difficult with children or people with cognitive impairments
“…research in university and medical settings must be approved by an institutional review board (IRB)…”
“…the American Psychological Association has published Ethical Principles of Psychologists and Code of Conduct, which includes general guidelines for conducting research…”
no harm
private data
if deception is necessary, must debrief
4-4: Chapter Review
Examining Psychopathology
Research involves establishing a hypothesis that is then tested. In psychopathology, research focuses on hypotheses meant to explain the nature, the causes, or the treatment of a disorder.
Types of Research Methods
The individual case study is used to study one or more individuals in depth. Although case studies have an important role in the theoretical development of psychology, they are not subject to experimental control and must necessarily be suspect in terms of both internal and external validity.
Research by correlation can tell us whether a relationship exists between two variables, but it does not tell us if that relationship is a causal one. Epidemiological research is a type of correlational research that reveals the incidence, distribution, and consequences of a particular problem in one or more populations.
Research by experiment can follow one of two designs: group or single case. In both designs, a variable (or variables) is manipulated, and the effects are observed to determine the nature of a causal relationship.
Genetics and Behavior across Time and Cultures
Genetic research focuses on the role of genetics in behavior. These research strategies include family studies, adoption studies, twin studies, genetic linkage analyses, and association studies.
Research strategies that examine psychopathology across time include cross-sectional and longitudinal designs. Both focus on differences in behavior or attitudes at different ages, but the former does so by looking at different individuals at different ages, and the latter looks at the same individuals at different ages.
Prevention research can be viewed in four broad categories: health promotion or positive development strategies, universal prevention strategies, selective prevention strategies, and indicated prevention strategies.
The clinical picture, causal factors, and treatment process and outcome can all be influenced by cultural factors.
The more the findings of a research program are replicated, the more they gain in credibility.
Ethics are important to the research process, and ethical guidelines are spelled out by many professional organizations in an effort to ensure the well-being of research participants.
Ethical concerns are being addressed through informed consent and through the inclusion of consumers in research design, implementation, and interpretation.
Notes from module
Practice Questions
In each of the statements provided, fill in the blanks with one of the following: hypothesis, dependent variable, independent variable, internal validity, external validity, or confound.
In a treatment study, the introduction of the treatment to the participants is referred to as the …
independent variable.
After the treatment study has been completed, you find that many people in the control group received treatment outside of the study. This is called a …
confound.
A researcher’s guess about what a study might find is labeled the …
hypothesis.
Scores on a depression scale improved for a treatment group after therapy. The change in these scores would be referred to as a change in the …
dependent variable.
A relative lack of confounds in a study would indicate good ???, whereas good generalizability of the results would be called good ???.
internal validity ; external validity
Check your understanding of research methods by indicating which would be most appropriate in each of the following situations. Choose from case study, correlation, randomized clinical trials, epidemiology, experiment, and single-case experimental design.
A researcher changes the level of noise several times to see how it affects concentration in a group of people.
experiment
A group of researchers uses chance assignment to include participants in one of two treatment groups and uses published protocols to make sure treatment is applied uniformly.
randomized clinical trials
A researcher wants to investigate the hypothesis that as children go through adolescence they listen to louder music.
correlation
A researcher is interested in studying a woman who had no contact with civilization and created her own language.
case study
A researcher wants to know how different kinds of music will affect a 5-year-old who has never spoken.
single-case experimental design
The following are some advantages and limitations of methods used in research across time. Sort them out by marking CS for cross-sectional designs and L for longitudinal designs.
Benefits:
Shows individual development
L
Easier
CS
No cohort effects
L
Limitations:
Cohort effects
CS
Cross-generational effect
L
No individual development data
CS
Indicate whether the following statements are true (T) or false (F).
After participants are told the nature of the experiment and their role in it, they must be allowed to refuse or agree to sign an informed consent form.
T
If the participant is in the control group or taking a placebo, informed consent is not needed.
F
Research in universities or medical settings must be approved by the institution’s review board regarding whether the participants lack the cognitive skills to protect themselves from harm.
T
Participants have a right to concealment of their identity on all data collected and reported.
T
When deception is essential to the research, participants do not have to be debriefed regarding the true pose of the study
F
educated guess or statement to be supported by data
hypothesis
observation that people of different age groups also differ in their values and experiences
cohort effect
participants in each age group of a cross-sectional research study
cohorts
degree to which two variables are associated
correlation
limit to the generalizability of longitudinal research because the group under study may differ from others in culture and experience
cross-generational effect
statistical measure that shows the amount of difference among the members of a group in a clinical study
effect size
ongoing scientific attempt to develop a comprehensive map of all human genes
human genome project
number of new cases of a disorder appearing during a specific time period
incidence
in genetics research, the individual displaying the trait or characteristic being studied
proband
when responses are measured on more than two occasions (not just before and after intervention) to assess trends
repeated measurement
literally “the view back,” data collected by examining records or recollections of the past. It is limited by the accuracy, validity, and thoroughness of the sources
retrospective information
combination of the cross-sectional and longitudinal research methods involving repeated study of different cohorts over time
sequential design
ability of a hypothesis, for example, to be subjected to scientific scrutiny and to be accepted or rejected, a necessary condition for the hypothesis to be useful
testability
studies of the effectiveness of clinical interventions, including the comparison of competing treatments
treatment outcome research
direction of change of a behaviour or behaviours (e.g., increasing, decreasing)
trend
degree of change in a phenomenon over time
variability
tendency to consider all members of a category as more similar than they are, ignoring their individual differences
patient uniformity myth
in outcome experiments, control groups that do not receive the experimental manipulation but are given a similar procedure with an identical expectation of change, allowing the researcher to assess any placebo effect
placebo control groups
number of people displaying a disorder in the total population at any given time
prevalence
plan of experimentation used to test a hypothesis
research design
in an experimental research study, the phenomenon that is measured and expected to be influenced
dependent variable
phenomenon that is manipulated by the experimenter in a research study and expected to influence the dependent variable
independent variable
extent to which the results of a research study can be attributed to the independent variable after confounding alternative explanations have been ruled out
internal validity
extent to which research study findings generalize, or apply, to people and settings not involved in the study
external validity
any factor occurring in a research study that makes the results uninterpretable because its effects cannot be separated from those of the variables being studied
confound (confounding variable)
group of individuals in a research study who are similar to the experimental subjects in every way but are not exposed to the treatment received by the experimental group
control group
method for placing individuals into research groups that assures each one of an equal chance of being assigned to any group, to eliminate any systematic differences across groups
randomization
approaches to research that use subjects who are similar to clinical clients, allowing replication of a clinical problem under controlled conditions
analogue models
extent to which research results apply to a range of individuals not in the study
generalizability
probability that obtaining the observed research findings merely by chance is small
statistical significance
degree to which research findings have useful and meaningful applications to real problems
clinical significance
research procedure in which a single person or small group is examined in detail
case study method
computed statistic reflecting the strength and direction of any association between two variables
correlation coefficient
association between two variables in which one increases as the other decreases
negative correlation
psychopathology research method examining the prevalence, distribution, and consequences of disorders in populations
epidemiology
research method that can establish causation by manipulating the variables in question and controlling for other alternative explanations of any observed effects
experiment
behavior change resulting from the person's expectation of change rather than from experimental manipulation
placebo effect
procedure in outcome studies that prevents bias by ensuring that neither the subjects nor the providers of the experimental treatment know who is receiving treatment and who is receiving placebo
double-blind control
outcome research that contrasts two or more treatment methods to determine which is most effective
comparative treatment research
research tactic in which an independent variable is manipulated for a single individual, allowing cause-and-effect conclusions, but with limited generalizability
single-case experimental design
removal of a treatment to note whether it has been effective
withdrawal design
measured rate of a behaviour before introduction of an intervention that allows comparison and assessment of the effects of the intervention
baseline
psychoanalytic therapy method in which dream contents are examined as symbolic of id impulses and intrapsychic conflicts
dream analysis
ethical requirement whereby research subjects agree to participate in a research study only after they receive full disclosure about the nature of the study and their own role in it
informed consent
single-case experimental design in which measures are taken on two or more behaviours, or on a single behaviour in two or more situations
multiple baseline
observable characteristics or behaviours of an individual
phenotypes
specific genetic makeup of individuals
genotypes
genetic mechanisms that contribute to the underlying problems causing the symptoms and difficulties experienced by people with psychological disorders
endophenotypes
genetic studies that examine patterns of traits and behaviours among relatives
family studies
in genetics research, the study of first-degree relatives reared in different families and environments
adoption studies
comparison of two offspring produced by the same pregnancy with unrelated or less closely related individuals
twin studies
studies that seek to match the inheritance pattern of a disorder to that of a genetic marker
genetic linkage analysis
inherited characteristic for which the chromosomal location of the responsible gene is known
genetic marker
research strategies for comparing genetic markers in groups of people with and without a particular disorder
association studies
methodology to examine a characteristic by comparing individuals of different ages
cross-sectional designs
systematic study of changes in the same individual or group examined over time
longitudinal design
Which of these plays an important role in ruling out the possibility that the results of a particular study were due to coincidence?
d. Replication
A researcher is studying how anxiety tends to be experienced by people of different ages. The researcher interviews depressed adolescents, young adults, individuals in their 30s and 50s, and those over 70. Everyone is assessed only once, during the same period. What design is the researcher employing?
Cross-sectional
What is one reason that longitudinal studies can be more difficult than cross-sectional studies to conduct?
Longitudinal studies can take many years to complete.
Dr. Claussen conducts research on early intervention programs for children and adolescents who are at risk of substance use disorders. All of this research has been conducted in a university setting under tightly controlled conditions with highly trained and well-supervised staff. Dr. Claussen is concerned about how well the research will generalize to the community and whether the intervention will be as successful in more diverse populations. What is Dr. Claussen concerned about?
External validity
Which of the following is intended to make sure that each person has an equal chance of being placed into the experimental or control group?
Randomization
Coincidences that lead to false conclusions are particularly problematic for which type of research?
Case study
One important difference between a typical case study and the single-case experiment is that the single-case experiment attempts to improve internal validity. How does it do so?
By making systematic observations of the same individuals under a variety of experimental conditions
Which term refers to the question of whether or not any observed differences or effects are meaningful for those impacted?
Clinical significance
What are the components of informed consent?
Competence, voluntarism, full information, and comprehension
Researchers who are enthused about a new treatment approach sometimes forget that their conclusions are based on group averages, like finding greater improvement in an experimental treatment group as compared to the improvement in a control group. In doing so, researchers may fail to consider that not everyone in the experimental group experienced improvement. What is this phenomenon called?
The patient uniformity myth
What is an individual's unique genetic makeup called?
Genotype
In experimental research, which group does not receive the independent variable and is used to determine whether the independent variable actually influenced change in the dependent variable?
Control
A researcher finds that the more time research participants spend on a treadmill, the more weight they lose. What does this relationship represent?
A positive correlation
The basis of which approach is manipulation of an independent variable and examining its effect on a dependent variable?
An experiment
In a family study, scientists examine a behavioral pattern or emotional trait in the context of the family. What do we call the family member with the trait of interest that has been singled out?
The proband
What is an educated guess about the results that will be found in research called?
A hypothesis
When a researcher is concerned about the extent to which the outcomes of their experiment are the result of the manipulation of the independent variable, what is the researcher is concerned about?
Internal validity
During the early months of the COVID-19 pandemic, some clinicians touted the use of certain medications for the treatment of COVID based on their clinical experiences with the drugs. Subsequent controlled research typically found the medications had no effect on outcomes or, in some cases, worsened the outcomes. Researchers speculated that the clinicians who found such encouraging results may have so strongly believed in those medications that they unconsciously treated the patients who took them more aggressively. What does this example illustrate?
An allegiance effect
What would an epidemiologist be most likely to study?
The prevalence of psychological disorders among veterans
In research, how are dependent variables treated?
They are measured or observed by the researcher.