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.
analgesic rebound headache
Headache, more severe than the original one, that occurs after the medication used to treat headache pain has
Approach to research that employs subjects who are similar to clinical clients, allowing replication of a clinical problem under controlled conditions.
Research strategies for comparing genetic markers in groups of people with and without a particular disorder.
Measured rate of a behavior before introduction of an intervention that allows comparison and assessment of the effects of the intervention.
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).
Degree to which research findings have useful and meaningful applications to real problems.
Participants in each age group of a study with a cross-sectional design.
Observation that people of different age groups differ in their values and experiences.
comparative treatment research
Outcome research that contrasts two or more treatment methods to determine which is most effective.
Any factor occurring in a study that makes the results uninterpretable because its effects cannot be separated from those of the variables being studied.
Variable in a research study that was not part of the intended design and that may contribute to changes in the dependent variable.
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.
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.
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.
Research procedure in which variables are measured and compared to detect any association but are not manipulated. Conclusions about cause-and-effect relationships are not permissible.
Limit on the generalizability of longitudinal research because the group under study may differ from others in culture and experience.
Methodology to examine a characteristic by comparing individuals of different ages (contrast with longitudinal design).
In an experimental study, the phenomenon that is measured and expected to be influenced (compare with independent variable).
Possibility that when two variables, A and B, are correlated variable A causes variable B or variable B causes variable A.
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.
Genetic mechanisms that contribute to the underlying problems causing the symptoms and difficulties experienced by people with psychological disorders.
Psychopathology research method examining the prevalence, distribution, and consequences of disorders in populations.
Cause or source of a disorder.
Research method that can establish causation by manipulating the variables in question and controlling for alternative explanations of any observed effects.
Extent to which research findings generalize, or apply, to people and settings not involved in the study.
Genetic studies that examine patterns of traits and behaviors among relatives.
functional communication training
Teaching of speech or nonspeech communication skills to replace undesired behavior. The new skills are useful to the person and will be maintained because of the effects they have on others.
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.
Inherited characteristic for which the chromosomal location of the responsible gene is known.
All of the hereditary information of an organism that is encoded in DNA.
Specific genetic makeup of an individual.
human genome project
Ongoing scientific attempt to develop a comprehensive map of all human genes.
Educated guess or statement to be tested by research.
Number of new cases of a disorder appearing during a specific period (compare with prevalence).
Phenomenon manipulated by the experimenter in a study and expected to influence the dependent variable.
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.
Extent to which the results of a study can be attributed to the independent variable after confounding alternative explanations have been ruled out.
Degree of behavior change with different interventions (for example, high or low).
Systematic study of changes in the same individual or group examined over time (contrast with cross-sectional design).
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.
Association between two variables in which one increases as the other decreases.
Studies examining the effectiveness and results, positive or negative, of treatment procedures.
patient uniformity myth
Tendency to consider all members of a category as more similar than they are, ignoring their individual differences.
Observable characteristics or behaviors of an individual.
A nonactive treatment that is successful due to suggestion.
placebo control group
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.
Behavior change resulting from the person''s expectation of change rather than from the experimental manipulation itself.
Association between two variables in which one increases as the other increases.
Number of people displaying a disorder in the total population at any given time (compare with incidence).
In genetics research, the individual displaying the trait or characteristic being studied.
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.
When responses are measured on more than two occasions (not just before and after intervention) to assess trends.
Confirming the results of a study by repeating it, often by a separate, independent researcher.
Plan of experimentation used to test a hypothesis.
Research that uses retrospective information and shares its limitations.
See withdrawal design.
Combination of the cross-sectional and longitudinal designs involving repeated study of different cohorts over time.
single-case experimental design
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).
Probability that obtaining the observed research findings merely by chance is small.
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.
treatment outcome research
Studies of the effectiveness of clinical interventions, including the comparison of competing treatments.
Direction of change of a behavior or behaviors (for example, increasing or decreasing).
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.
Degree of change in a phenomenon over time.
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.