An organized set of concepts that explains a phenomenon or set of phenomena.
The doctrine that all events--physical, behavioral, and mental-- are determined by specific causal factors that are potentially knowable.
A tentative and testable explanation of the relationship between two (or more) events or variables; often stated as a prediction that a certain outcome will result from specific conditions.
The distortion of evidence because of the personal motives and expectations of the viewer.
A set of uniform procedures for treating each participant in a test, interview, or experiment, or for recording data.
A definition of a variable or condition in terms of the specific operation or procedure used to determine its presence.
In an experimental setting, a factor that varies in amount and kind.
In an experimental setting, a variable that the researcher manipulates with the expectation of having an impact on values of the dependent variable.
In an experimental setting, a variable that the researcher measures to assess the impact of a variation in an independent variable.
Research methodology that involves the manipulation of independent variables to determine their effects on the dependent variables.
A stimulus other than the variable an experimenter explicitly introduces into a research setting that affects a participant's behavior.
Result that occurs when a researcher or observer subtly communicates to participants the kind of behavior he or she expects to find, thereby creating that expected reaction.
A change in behavior in the absence of an experimental manipulation.
Consistent procedure for giving instructions, scoring responses, and holding all other variables constant except those being systematically varied.
An experimental technique in which biased expectations of experimenters are eliminated by keeping both participants and experimental assistants unaware of which participants have received which treatment.
An experimental condition in which treatment is not administered; it is used in cases where a placebo effect might occur.
A research design in which different groups of participants are randomly assigned to experimental conditions or to control conditions.
A procedure by which participants have an equal likelihood of being assigned to any condition within an experiment.
A group in an experiment that is exposed to a treatment or experiences a manipulation of the independent variable.
A group in an experiment that is not exposed to a treatment or does not experience a manipulation of the independent variable.
The entire set of individuals to which generalizations will be made based on an experimental sample.
A subset of a population selected as participants in an experiment.
A subset of a population that closely matches the overall characteristics of the population with respects to the distribution of males and females, racial and ethnic groups, and so on.
A procedure that ensures that every member of a population has an equal likelihood of participating in an experiment.
A research design that uses each participant as his or her own control; for example, the behavior of an experimental participant before receiving treatment might be compared to his or her behavior after receiving treatment.
Research methodology that determines to what extent two variables, traits, or attributes are related.
A statistic that indicates the degree of relationship between two variables.
The degree to which a test produces similar scores each time it is used; stability or consistency of the scores produced by an instrument.
The extent to which a test measures what it was intended to measure.
A self-behavior that is identified through a participants's own observations and reports.
Overt actions or reaction that is observed and recorded, exclusive or self-reported behavior.
A research technique in which unobtrusive observations are made of behaviors that occur in natural environments.
Intensive observation of a particular individual or small group of individuals.
The process through which individuals are informed about experimental procedures, risks and benefits before they provide formal consent to become research participants.
A procedure conducted at the end of an experiment in which the researcher provides the participant with as much information about the study as possible and makes sure that no participant leaves feeling confused, upset, or embarrassed.