Ch 4: Research Methods

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

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

correlation

Degree to which two variables are associated.

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.

Scientific process …kinda…. very simplified

A → B + what/who you are measuring

Hypothesis ; research design

“?? create in the controlled conditions of the laboratory aspects that are comparable (analogous) to the phenomenon under study…”

Analogue models

“In psychological research, ?? typically means that the probability of obtaining the observed effect by chance is small.”

statistical significance

“The difficulty is in the distinction between ?A? (a mathematical calculation about the difference between groups) and ?B? (whether or not the difference was meaningful for those affected).”

statistical significance ; clinical significance

A?: “…, the number of people with a disorder at any one time…”

B?: “…of a disorder, the estimated number of new cases during a specific period…”

prevalence ; incidence

what are case studies good for?

studying one specific individual or case

Group Experimental Designs

researchers change IV to see changes in groups

change/manipulation in IV may not occur naturally

“A ??? is an experiment used to determine the effectiveness and safety of a treatment or treatments. The term ??? implies a level of formality with regard to how it is conducted. As a result, a ??? is not a design by itself but rather a method of evaluation that follows a number of generally accepted rules.”

clinical trial

“…???, which are experiments that employ randomization of participants into each experimental group.”

randomized clinical trials

“Another subset of clinical trials is ???, which are used to describe experiments that rely on control conditions to be used for comparison purposes.”

controlled clinical trials

trial which “…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

“…a ?? is nearly identical to the treatment group in such factors as age, gender, socioeconomic backgrounds, and the problems they are reporting.”

control group

“?? focuses on the mechanisms responsible for behavior change…”

Process research

“…?? involves finding out why or how your treatment works.”

treatment process

“…?? involves finding out what changes occur after treatment.”

treatment outcome

??: measure behavior multiple times before changing IV to see any changes/trends

Repeated Measurements

What are Withdrawal Designs

stop treatment (IV) and see what happens

3 parts of Withdrawal Designs

identify baseline, then change IV and see what happens, then remove IV and see what happens (“return to baseline“)

“?? are periods when the medication is withdrawn so that clinicians can determine whether it is responsible for the treatment effects.”

Drug holidays

??: “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.”

Multiple Baseline

?? : “…the genetic mechanisms that ultimately contribute to the underlying problems causing the symptoms and difficulties experienced by people with psychological disorders…”

endophenotyopes

what relatives are more likely to have genes

direct (first-degree)

“…?? twins … have identical genes.”

identical (monozygotic)

“??? 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.”

Fraternal (dizygotic)

“Whereas ?A? compare markers in a large group of people with a particular disorder, ?B? 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.”

linkage studies ; association studies

A? “…(which record changes over time as they occur)…”

B? “… (which ask people to remember what happened in the past…).”

Prospective studies ; retrospective studies

“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

“??? involve efforts to blanket entire populations of people—even those who may not be at risk—to prevent later problems and promote protective behaviors.”

Health promotion or positive development 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.”

Universal prevention strategies

“… 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.”

selective 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.”

indicated prevention

“True informed consent is at times elusive. The basic components are …”

competence, voluntarism, full information, and comprehension on the part of the participant

“…research in university and medical settings must be approved by …”

an institutional review board (IRB)

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 ?A?, whereas good generalizability of the results would be called good ?B?.

internal validity ; external validity

which would be most appropriate in each of the following situations. (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

which would be most appropriate in each of the following situations. (case study, correlation, randomized clinical trials, epidemiology, experiment, and single-case experimental design)

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

which would be most appropriate in each of the following situations. (case study, correlation, randomized clinical trials, epidemiology, experiment, and single-case experimental design)

A researcher wants to investigate the hypothesis that as children go through adolescence they listen to louder music.

correlation

which would be most appropriate in each of the following situations. (case study, correlation, randomized clinical trials, epidemiology, experiment, and single-case experimental design)

A researcher is interested in studying a woman who had no contact with civilization and created her own language.

case study

which would be most appropriate in each of the following situations. (case study, correlation, randomized clinical trials, epidemiology, experiment, and single-case experimental design)

A researcher wants to know how different kinds of music will affect a 5-year-old who has never spoken.

single-case experimental design