Chapter Five Measurement Concepts

Terms Reliability True Score Measurement Error

How Can we assess Reliability Test-Retest Reliability Internal Consistency Reliability –Split half reliability –Cronbach’s alpha Inter-rater reliability

Reliability vs. Validity Reliability-consistency of the measure Validity-truth---does the study measure what it says it will measure…is it valid ****A measure can be reliable and not valid, but it canno be valid unless it is reliable.

Construct validity  the adequacy of the operational definitions of variables Criterion-Oriented Validity- examining the relationship between scores on a measure and some criterion.

Indicators of Validity Face validity  tells whether the measure appears to measure what it is suppose to.. Four types of Criterion-related research approaches

Types of Criterion-oriented research approaches Predictive Validity Concurrent Validity Convergent Validity Discriminant Validity

Predictor Validity- research measuring the extent to which the measure allows you to predict future behaviors. (SAT) Concurrent Validity-examines the relationship between the measure and a criterion at the same time. –research whether two or more groups of people differ on a measure in expected ways. Convergent validity  when a measure relates to other scores of the same or similar constructs in a meaningful and predicted way. –Shy Q scores and Fear of Negative Evaluation Scale Discriminant validity  the measure should discriminate between the construct being measured and other non-related constructs. –Shy Q and Zuckerman’s Sensation seeking Scale.

Variables & Measurement Scales Nominal scales  have no numerical or quantitative properties, they are naming scales, and their only property is identity. Ordinal scales  tell us about the relative order of magnitude, but they do not give us info about the differences b/t categories or ranks. Interval scale  the measurement conveys info about the order and the distance b/t the values Ratio scales  have all the properties of the previous scales and a true zero point that indicates the absence of the variable being measured