P
the tendency to believe, after learning an outcome, that one would have foreseen it.
Hindsight Bias
thinking that does not blindly accept arguments and conclusions. Rather, it examines assumptions, assesses the source, discerns hidden values, evaluates evidence, and assesses conclusions
Critical thinking
an explanation using an integrated set of principles that organizes observations and predicts behaviors or events
Theory
a testable prediction often implied by a theory
Hypothesis
a carefully worded statement of the exact procedures (operations) used in a research study. For example, human intelligence may be operationally defined as what an intelligence test measures
Operational Definition
repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances
Replication
a descriptive technique in which one individual or group is studied in depth in the hope of revealing universal principles
Case Study
observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation
Naturalistic Observation
a technique for ascertaining the self-reported attitudes or behaviors of a particular group, usually by questioning a representative, random sample of the group
Survey
a flawed sampling process that produces an unrepresentative sample
Sampling Bias
all those in a group being studied, from which samples may be drawn (except for national studies, does not apply to a country's entire population)
Population
a sample that fairly represents a population because each member has an equal chance of inclusion
Random Sample
a measure of the extent to which two variables change together, and thus of how well either variable predicts the other
Correlation
a statistical index of the relationship between two variables
Correlation Coefficient
the perception of a relationship where none exists
Illusory Correlation
a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter = high correlation).
Scatterplot
a research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable). By random assignment of participants, the experimenter aims to control other relevant variables.
Experiment
in an experiment, the group exposed to the treatment, that is, to one version of the independent variable.
Experimental Group
in an experiment, the group not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.
Control Group
assigning participants to experimental and control groups by chance, thus minimizing preexisting differences between the different groups
Random Assignment
an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.
Double-blind Procedure
experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes in an active agent.
Placebo Effect
the experimental factor that is manipulated; the variable whose effect is being studied
Independent Variable
a factor other than the independent variable that might produce an effect in an experiment
Confounding Variable
the outcome factor; the variable that may change in response to manipulations of the independent variable
Dependent Variable