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Hindsight bias

Tendency to believe, after learning an outcome, that one would have foreseen it.

Critical thinking

Thinking that doesn't blindly accept arguments and conclusions, but rather examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions

Theory

Explanation using integrated set of principles that organizes and predicts observations.

Hypothesis

Testable prediction, often implied by theory

Operational definition

Statement of procedures used to define research variables

Replication

Repeating essence of a research study to see whether basic findings extend to other participants and circumstances

Case study

Observation technique where one person is studied in depth in hope of revealing universal principles

Survey

Technique for ascertaining self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them

False consensus effect

Tendency to overestimate the extent to which others share our beliefs and behaviors

Population

All the cases in a group, from which samples may be drawn for a study

Random sample

Sample that fairly represents population because each member has equal chance of inclusion

Naturalistic observation

Observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation

Correlation

Measure of the extent to which two factors vary together, and thus how well each factor predicts the other

Scatterplot

Graphed cluster of dots, each of which represented values of two variables. Slope of points suggest direction of relationship between two variables. Amount of scatter suggests strength of correlation

Illusory correlation

Perception of a relationship when none exists

Experiment

Research method in which investigator manipulates one or more factors go observe the effect on some behavior or mental process.

Double-blind procedure

Experimental procedure in which both research participants and research staff are ignorant about whether research participants have received the treatment or placebo

Placebo effect

Experimental results caused by expectations alone; any effect on behavior caused by administration of inert substance or condition, which is assumed to be an active agent

Experimental condition

Condition of experiment that exposes participants to treatment, that is, to one version of independent variable

Control condition

Condition of experiment that contrasts with experimental condition and serves as comparison for evaluating effect of treatment

Random assignment

Assigning participants to experimental and control conditions by chance, thus minimizing preexisting differences between those assigned to different groups

Independent variable

Experimental factor that is manipulated; variable whose effect is being studied

Dependent variable

Outcome factor, variable that may change in response to manipulations of independent variable

Mode

Most frequently occurring score in a distribution

Mean

Arithmetic average of a distribution, obtained by adding scores and dividing by the number of scores

Median

Middle score in distribution, half the scores are above it and half are below it

Range

Difference between highest and lowest scores in distribution

Standard deviation

Computed measure of how much scores may vary around the mean score

Statistical significance

Statistical statement of how likely it is that an obtained result occurred by chance

Culture

Enduring behaviors, ideas, attitudes, and traditions shared by a large group of people and transmitted from one generation to the next