Transcript Chapter Five

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