Chapter 2

Applied science

science concerned with solving some real-world problem of importance.

Basic science

science concerned with trying to understand some phenomenon in its own right, with a view toward using that understanding to build valid theories about the nature of some aspect of the world.

Control condition

condition comparable to the experimental condition in every way except that it lacks the one ingredient hypothesized to produce the expected effect on the dependent variable.

Convenience sample

taken from some available subgroup in the population

Correlational research

research that does not involve random assignment to different situations, or conditions, and that psychologists conduct just to see whether there is a relationship between the variables.

Debriefing

in preliminary versions of an experiment, asking participants straightforwardly if they understood the instructions, found the setup to be reasonable, and so forth. In later versions, debriefings are used to educate participants about the questions being

Deception research

research in which the participants are misled about the purpose of the research or the meaning of something that is done to them

Dependent variable

in experimental research, the variable that is measured (as opposed to manipulated); it is hypothesized to be affected by manipulation of the independent variable.

Experimental research

in social psychology, research that randomly assigns people to different conditions or situations and that enables researchers to make strong inferences about how these different conditions affect people's behavior.

External validity

an experimental setup that closely resembles real-life situations so that results can safely be generalized to such situations.

Field experiment

an experiment set up in the real world, usually with participants who are not aware that they are in a study of any kind.

Hindsight bias

people's tendency to be overconfident about whether they could have predicted a given outcome

Hypothesis

prediction about what will happen under particular circumstances.

Independent variable

in experimental research, the variable that is manipulated; it is hypothesized to be the cause of a particular outcome.

Informed consent:

participant's willingness to participate in a procedure or research study after learning all relevant aspects about the procedure or study.

Institutional review board (IRB)

university committee that examines research proposals and makes judgments about the ethical appropriateness of the research.

Internal validity

in experimental research, confidence that only the manipulated variable can have produced the results

Intervention

an effort to change people's behavior.

Longitudinal study

study conducted over a long period of time with the same population, which is periodically assessed regarding a particular behavior

Measurement validity

correlation between some measure and some outcome that the measure is supposed to predict

Natural experiments

naturally occurring events r phenomena having somewhat different conditions that can be compared with almost as much rigor as in experiments where the investigator manipulates the conditions.

Population

group you want to know about

Random assignment

assigning participants in experimental research to different groups randomly, such that they are as likely to be assigned to one condition as the other.

Random sampling

taken at random from population; everyone has an equal chance to be in the sample.

Reliability

degree to which the particular way that researchers measure a given variable is likely to yield consistent results.

Reverse causation

when variable 1 is assumed to cause variable 2, yet the opposite direction of causation may be the case.

Self-selection

problem that arises when the participant, rather than the investigator, selects his or her level on each variable, bringing with this value unknown other properties that make causal interpretation of a relationship difficult.

Statistical significance

measure of the probability that a given result could have occurred by chance

Theory

body of related propositions intended to describe some aspect of the world.

Third variable

when variable 1 does not cause variable 2 and variable 2 does not cause variable 1, but rather some other variable exerts a causal influence on both.