Psych 2e Chapter 2

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

Theory

A testable prediction about how the world will behave if a theory is correct.

Hypothesis

An in-depth study of one or a few individuals, often with rare conditions.

Clinical or Case Study

Observing behavior in its natural setting without intervention or control.

Naturalistic Observation

When a researcher’s expectations affect their observations and interpretations.

Observer Bias

The level of agreement among different observers of the same event.

Inter-rater Reliability

A method for gathering large amounts of self-reported data from many people.

Survey

Research using existing records to answer questions or conduct comparisons.

Archival Research

A research design that follows the same group of individuals over time.

Longitudinal Research

A research design that compares different population groups at a single time point.

Cross-sectional Research

A relationship between two or more variables.

Correlation

A number from –1 to +1 that indicates the strength and direction of a relationship.

Correlation Coefficient (r)

Variables move in the same direction; as one increases, so does the other.

Positive Correlation

Variables move in opposite directions; as one increases, the other decreases.

Negative Correlation

The false perception of a relationship between variables when none exists.

Illusory Correlation

Tendency to focus on information that confirms existing beliefs.

Confirmation Bias

The ability to demonstrate that one variable directly influences another, possible only in experiments.

Cause-and-Effect

The group in an experiment that receives the treatment or manipulation.

Experimental Group

The group that does not receive the treatment; used for comparison.

Control Group

A subset of a population chosen so every member has an equal chance of inclusion.

Random Sample

The overall group that researchers are interested in studying.

Population

Assigning participants to groups in a way that every participant has an equal chance.

Random Assignment

The variable that is manipulated in an experiment.

Independent Variable

The variable that is measured in an experiment.

Dependent Variable

A description of how variables are measured or defined in a study.

Operational Definition

Participants do not know whether they are in the control or experimental group.

Single-blind Study

Neither participants nor researchers know who is in which group.

Double-blind Study

When expectations of participants cause changes in behavior or symptoms.

Placebo Effect

When a researcher’s expectations skew the study’s results.

Experimenter Bias

The extent to which an experiment measures what it intends to measure.

Validity

The consistency of a measure or test over time.

Reliability

Determines if results are due to chance or reflect true differences.

Statistical Analysis

An article reviewed by experts before being published.

Peer-reviewed Journal Article

A committee that reviews research to ensure ethical standards are met.

Institutional Review Board (IRB)

The process of providing participants with full disclosure before they agree to participate.

Informed Consent

Deliberately misleading participants, which must be justified and followed by debriefing.

Deception

Participants are informed of the true nature and purpose of the study after it ends.

Debriefing

Individuals who take part in a study.

Participants

The subset of individuals selected from a population to participate in a study.

Sample

The process of repeating a study to confirm the results.

Replication

Personal beliefs or judgments that may not be based on evidence.

Opinion