Contents

Glossary 449demand characteristics Cues and other information used by participants to guide theirbehavior in a psychological study, often leading participants to do what they believethe observer (experimenter) expects them to do.dependent variable Measure of behavior used by the researcher to assess the effect(if any) of the independent variable.differential transfer Potential problem in repeated measures designs when performancein one condition differs depending on the condition preceding it.double-blind procedure Both the participant and the observer are kept unaware(blind) of what treatment is being administered.effect size Index of the strength of the relationship between the independent variableand dependent variable that is independent of sample size.empirical approach Approach to acquiring knowledge that emphasizes direct observationand experimentation as a way of answering questions.estimated standard error of the mean An estimate of the true standard errorobtained by dividing the sample standard deviation by the square root of the samplesize.eta squared ( 2 ) A measure of the strength of association (or effect size) based on theproportion of variance accounted for by the effect of the independent variable on thedependent variable.ethnocentrism An attempt to understand the behavior of individuals in different culturesbased solely on experiences in one’s own culture.experiment A controlled research situation in which scientists manipulate one or morefactors and observe the effects of this manipulation on behavior.experimenter effects Experimenters’ expectations that may lead them to treat subjectsdifferently in different groups or to record data in a biased manner.external validity The extent to which the results of a research study can be generalizedto different populations, settings, and conditions.factorial design See complex design.field experiment Procedure in which one or more independent variables is manipulatedby an observer in a natural setting to determine the effect on behavior.floor effect See ceiling effect.F-test In the analysis of variance, or ANOVA, the ratio of between-group variation andwithin-group or error variation.getting to know the data In this first stage of data analysis the researcher inspects thedata for errors and outliers and generally becomes familiar with the general featuresof the data.Hawthorne effect See novelty effects.history The occurrence of an event other than the treatment that can threaten internalvalidity if it produces changes in the research participants’ behavior.hypothesis A tentative explanation for a phenomenon.idiographic approach Intensive study of an individual, with an emphasis on bothindividual uniqueness and lawfulness.independent groups design Each separate group of subjects in the experimentrepre sents a different condition as defined by the level of the independent variable.independent variable Factor for which the researcher manipulates at least two levelsin order to determine its effect on behavior.individual differences variable A characteristic or trait that varies consistently acrossindividuals, such as level of depression, age, intelligence, gender. Because this variableis formed from preexisting groups (i.e., it occurs “naturally”) an individual differencesvariable is sometimes called a natural groups variable. Another term sometimes usedsynonymously with individual differences variable is subject variable.