As a function of
A way to describe a relationship using the format “changes in Y as a function of changes in X
condition
An amount or category of the independent variable that creates the specific situation under which subjects’ scores on the dependent variable are measured.
continuous scale
A measurement scale that allows for fractional amounts of the variable being measured.
correlational study
A procedure in which participants’ scores on two variables are measured, without manipulation of either variable, to determine whether they form a relationship.
dependent variable
In an experiment, the variable that is measured under each condition of the independent variable.
descriptive statistics
Procedures for organizing and summarizing data so that the important characteristics can be described and communicated.
design
The way in which a study is laid out so as to demonstrate a relationship.
dichotomous variable
A discrete variable that has only two possible amounts or categories.
discrete scale
A measurement scale that allows for measurement only in whole amounts.
experiment
A research procedure in which one variable is actively changed or manipulated, the scores on another variable are measured, and all other variables are kept constant, to determine whether a relationship exists.
independent variable
In an experiment, a variable that is changed or manipulated by the experimenter; a variable hypothesized to cause a change in the dependent variable.
individual differences
Variations in individuals’ traits, backgrounds, genetic makeup, etc., that influence their behavior in a given situation and thus the strength of a relationship.
inferential statistics
Procedures for determining whether sample data represent a particular relationship in the population.
interval scale
A measurement scale in which each score indicates an actual amount and there is an equal unit of measurement between consecutive scores, but in which zero is simply another point on the scale (not zero amount).
level
In ANOVA, each condition of the factor (independent variable); also called treatment.
nominal scale
A measurement scale in which each score is used simply for identification and does not indicate an amount.
ordinal scale
A measurement scale in which scores indicate rank order.
parameter
A number that describes a characteristic of a population of scores, symbolized by a letter from the Greek alphabet; also called a parameter.
participants
The individuals who are measured in a sample; also called subjects.
population
The infinitely large group of all possible scores that would be obtained if the behavior of every individual of interest in a particular situation could be measured.
ratio scale
A measurement scale in which each score indicates an actual amount, there is an equal unit of measurement, and there is a true zero.
relationship
A correlation between two variables whereby a change in one variable is accompanied by a consistent change in the other.
sample
A relatively small subset of a population, intended to represent the population; a subset of the complete group of scores found in any particular situation.
statistic
A number that describes a characteristic of a sample of scores, symbolized by a letter from the English alphabet; also called a statistic.
