PSYCH 312: Chapter 4

operational definition

a definition of the variable in terms of precisely how it is to be measured

convergent validity

a form of criterion validity whereby new measures are correlated with existing established measures of the same construct

concurrent validity

a form of criterion validity, where the criterion is measured at the same time (concurrently) as the construct

predictive validity

a form of validity whereby the criterion is measured at some point in the future (after the construct has been measured), to determine that the construct "predicts" the criterion

ratio level

a measurement that involves assigning scores in such a way that there is a true zero point that represents the complete absence of the quantity

ordinal level

a measurement that involves assigning scores so that they represent the rank order of the individuals

interval level

a measurement that involves assigning scores using numerical scales in which intervals have the same interpretation throughout

nominal level

a measurement used for categorical variables and involves assigning scores that are category labels

split-half correlation

a score that is derived by splitting the items into two sets and examining the relationship between the two sets of scores in order to assess the internal consistency of a measure

Cronbach's α

a statistic that measures internal consistency among items in a measure

psychometrics

a subfield of psychology concerned with the theories and techniques of psychological measurement

criterion (pl. criteria)

a variable that theoretically should be correlated with the construct being measured

conceptual definition

describes the behaviors and internal processes that make up a psychological construct, along with how it relates to other variables

levels of measurement

four categories, or scales, of measurement (i.e., nominal, ordinal, interval, and ratio) that specify the types of information that a set of scores can have, and the types of statistical procedures that can be used with the scores

self-report measures

measures in which participants report on their own thoughts, feelings, and actions

behavioral measures

measures in which some other aspect of participants' behavior is observed and recorded

physiological measures

measures that involve recording any of a wide variety of physiological processes, including heart rate and blood pressure, galvanic skin response, hormone levels, and electrical activity and blood flow in the brain

constructs

psychological variables that represent an individual's mental state or experience, often not directly observable, such as personality traits, emotional states, attitudes, and abilities

reliability

refers to the consistency of a measure

demand characteristics

subtle cues that reveal to participants how the researcher expects them to respond in the experiment

measurement

the assignment of scores to individuals so that the scores represent some characteristic of the individuals

internal consistency

the consistency of people's responses across the items on a multiple-item measure

content validity

the extent to which a measure reflects all aspects of the construct of interest

face validity

the extent to which a measurement method appears, on superficial examination, to measure the construct of interest

inter-rater reliability

the extent to which different observers are consistent in their judgments

criterion validity

the extent to which people's scores on a measure are correlated with other variables (known as criteria) that one would expect them to be correlated with

discriminant validity

the extent to which scores on a measure of a construct are not correlated with measures of other, conceptually distinct, constructs and thus discriminate between them

validity

the extent to which the scores from a measure represent the variable they are intended to

socially desirable responding

when participants respond in ways that they think are socially acceptable

converging operations

when psychologists use multiple operational definitions of the same construct—either within a study or across studies

test-retest reliability

when researchers measure a construct that they assume to be consistent across time, then the scores they obtain should also be consistent across time