Key Terms

archival research

Method of research using past records or data sets to answer various research questions, or to search for interesting patterns or relationships.

attrition

Reduction in number of research participants as some drop out of the study over time.

cause-and-effect relationship

Changes in one variable cause the changes in the other variable; can be determined only through an experimental research design.

clinical or case study

Observational research study focusing on one or a few people.

confirmation bias

Tendency to ignore evidence that disproves ideas or beliefs.

confounding variable

Unanticipated outside factor that affects both variables of interest, often giving the false impression that changes in one variable causes changes in the other variable.

control group

Serves as a basis for comparison and controls for chance factors that might influence the study results.

correlation

Relationship between two or more variables; when two variables are correlated, one variable changes as the other does.

correlation coefficient

Number from -1 to +1, indicating the strength and direction of the relationship between variables.

cross-sectional research

Compares multiple segments of a population at a single time.

debriefing

Participants are told complete and truthful information about the experiment at its conclusion when deception is involved.

deception

Purposely misleading experiment participants to maintain the integrity of the experiment.

deductive reasoning

Results are predicted based on a general premise.

dependent variable

Variable that the researcher measures to see how much effect the independent variable had.

double-blind study

Experiment in which both the researchers and the participants are blind to group assignments.

empirical

Grounded in objective, tangible evidence that can be observed consistently.

experimental group

Group designed to answer the research question; experimental manipulation is the only difference from the control group.

experimenter bias

Researcher expectations skew the results of the study.

fact

Objective and verifiable observation, established using empirical research evidence.

falsifiable

Able to be disproven by experimental results.

generalize

Inferring that the results for a sample apply to the larger population.

hypothesis

A testable prediction about phenomena, often in an if-then statement.

illusory correlation

Seeing relationships between two things when no such relationship exists.

independent variable

Variable influenced or controlled by the experimenter; the only important difference between groups in a sound study.

inductive reasoning

Conclusions are drawn from observations.

informed consent

Process of informing research participants about what to expect during an experiment and obtaining consent.

Institutional Animal Care and Use Committee (IACUC)

Committee that reviews proposals for research involving non-human animals.

Institutional Review Board (IRB)

Committee that reviews proposals for research involving human participants.

inter-rater reliability

Measure of agreement among observers on how they record and classify a particular event.

longitudinal research

Studies where the same group of individuals is surveyed or measured repeatedly over time.

naturalistic observation

Observation of behavior in its natural setting.

negative correlation

Two variables change in different directions; not the same as no correlation.

observer bias

Observations may be skewed to align with observer expectations.

operational definition

Description of what actions will be used to measure and manipulate variables.

opinion

Personal judgments or conclusions that may or may not be accurate.

participants

Subjects of psychological research.

peer-reviewed journal article

Article reviewed by experts whose feedback determines its quality before publication.

placebo effect

Influence of people's expectations or beliefs on their experiences.

population

Overall group of individuals that researchers are interested in.

positive correlation

Two variables change in the same direction.

random assignment

Method of assigning participants to groups where each has an equal chance of being chosen.

random sample

Subset of a larger population where all members have an equal chance of selection.

reliability

Consistency and reproducibility of results.

replicate

Repeating an experiment to determine reliability.

sample

Subset of individuals selected from a larger population.

single-blind study

Experiment where the researcher knows group assignments but participants do not.

statistical analysis

Determines likelihood that differences between experimental groups are due to chance.

survey

List of questions answered by research participants to collect data from a large group.

theory

Well-developed set of ideas proposing explanations for observed phenomena.

validity

Accuracy of a result in measuring what it is designed to measure.