Psychology 2e Chapter 2: Psychological Research

Theory

A well-developed set of ideas that propose an explanation for observed phenomena

Hypothesis

A scientific, informed, and testable prediction of the outcome of a particular set of conditions in a research design.

Reliability

The consistency and reproductivity of a given result.

Validity

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

Replication

The repetition of a study to confirm the results; essential to the scientific process.

Population

The entire group a researcher is interested in, Ex. all humans, all adolescents, etc.

Samples

Subsets of a larger population studied in a research project.

Case Study

A study design in which a psychologist observes one person or a few people over a long period of time.

Naturalistic observation

A study in which the researcher unobtrusively observes and records behavior in the real world.

Correlation

Relationship between 2 or more variables; one variable changes as the other does, can be either negative or positive.

Correlation coefficient

Number that ranges from -1.0 to +1.0 and assess the strength and direction of association between two variables, usually represented by the letter “r”.

Independent variable

A property that is manipulated by the experimenter under controlled conditions to determine whether it causes the predicted outcome of an experiment

Dependent variable

In an experiment, the outcome or response to the experimental manipulation; caused by the independent variable.

Random assignment

The method used to assign participants to different research conditions, so that all participants have the same change of being in any specific group.

Experimental group

A group consisting of those participants who will receive the treatment or whatever is predicted to change behavior.

Control group

A group of research participants who are treated in exactly the same manner as the experimental group, except that they do not receive the independent variable or treatment.

Placebo

A substance or treatment that appears identical to the actual treatment but lacks the active substance.

Confounding variable

Unanticipated outside factor that affects both variables, often communicating false information about causation.

Single-blind studies

Studies in which the participants do not know the experimental condition (group) to which they have been assigned to.

Double-blind studies

Studies in which neither the participants nor the researchers administering the treatment know who has been assigned to the experimental or control group.

Experimenter bias

Researcher’s expectations skew the results of the study.

Longitudinal research

Make observations of the same people over time, ranging from months to decades.

Ethics

The rules governing the conduct of a person or group in general or in a specific situation- or more simply, the standards of right and wrong.

Falsifiable

Able to be disproven by experimental results.

Debriefing

The explanation of the purpose of a study following data collection (when an experiment involved deception).

Institutional Review Boards (IRBs)

Organizations that evaluate research proposals to make sure research involving humans does not cause undue harm or distress.

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

Confirmation bias

The tendency to ignore evidence that disproves one’s ideas or beliefs

Cross-sectional research

Compares multiple segments of a population at a single time

Deductive reasoning

Logical approach based on a general premise that leads to more specific conclusions: hypothesis —> this vocab —> empirical observations

Inductive reasoning

Logical approach that draws conclusions from observations: empirical observations —> this vocab —> hypothesis/general premise

Negative Correlation

Two variables change in different directions, with one becoming larger as the other becomes smaller: inverse.

Positive Correlation

Two variables change in the same direction, both becoming either larger or smaller at the same time.

Inter-rater reliability

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

Statistical analysis

Determines how likely any difference between experimental groups is due to chance: determines if something is statistically significant or not