hindsight bias
the tendency to believe, after learning an outcome, that one would have forseen it (knew-it-all-along phenomenon)
critical thinking
examines assumptions, discerns hidden values, evaluates evidence, and assesses conclusions (smart thinking)
theory
explains through an integrated set of principles that organizes observations and predicts behaviors or events (explanation)
hypothesis
a testable prediction, often implied by a theory (testable prediction)
operational definition
a statement of the procedures used to define research variables (statement defining research)
replication
repeating the essence of a research study, usually with different participants in different situations, to see whether the baic finding extends to other participants and circumstances (re-creating a study)
case study
an observation technique in which one person is studied in depth in the hope of revealing universal principles (individually studied in depth)
survey
a technique for ascertaining the self-reported attitudes or behaviors of people, usually by questioning a representative, random sample of them (reported attitudes and behaviors)
population
all the cases in a group, from which samples may be drawn for a study (cases in a group)
random sample
a sample that fairly represents a population because each member has an equal chance of inclusion (represents population)
naturalistic observation
observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation (naturally occurring behaviors)
correlation
a measure of the extent to which two factors vary together, and thus of how well either factor predicts the other (two facors vary together)
correlation coefficient
the mathematical expression of the relationship (statistical measure)
scatterplot
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 (graphed cluster
illusory correlation
the perception of a relationship where none exists (nonexistent correlation)
experiment
a research method in which an investigator manipulates one or more factors to observe the effect on some behavior or mental process (cause and effect method)
random assignment
assigning participants to experiment and control conditions by chance, thus minimizing preexisting differences between those assigned to the different groups (assigning by control and chance)
double-blind procedure
an experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo (treatment's actual effect)
placebo effect
experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent (results caused by expectations)
experimental group/condition
the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable (exposes participant to treatment)
control group/condition
the condition of an experiment that contrasts with the experimental condition and serves as a comparison for evaluating the effect of the treatment (without treatment)
independent variable
the experimental factor that is manipulated; the variable whose effect is being studied (manipulated factor)
dependent variable
the outcome factor; the variable that may change in response to manipulations of the independent variable (outcome factor)
mode
most frequently occurring score(s) in a distribution (most often)
mean
the arithmetic average of a distribution, adding scores then dividing by the number of scores (average)
median
the middle score in a distribution (middle)
range
the difference between the highest and lowest scores in a distribution (difference)
standard deviation
a computed measure of how much scores vary around the mean score (how much scores vary)
normal curve
the symmetrical bell-shaped curve that describes the distribution of many physical and psychological attributes. most scores fall near the average, and fewer and fewer scores lie near the extremes (bell-shaped pattern)
statistical significance
a statistical statement of how likely it is that an obtained result occurred by chance (likelihood of occurring by chance)
culture
the enduring behaviors, ideas, attitudes and traditions shard by a large group of people and transmitted from one generation to the next (shared ideas and behaviors)