Reliability
This reliability indicator shows that the same individuals may be measured at two separate points in time.
Test-retest
Does the measurement accurately measure the variable it is intended to measure? Good! It has this.
Face Validity
This potential problem when measuring behavior occurs when the awareness of being measured changes the individual's behavior.
Reactivity
You'll need a computer to calculate this indicator of reliability, which is based on internal consistency and provides the average of all possible split-half reliability coefficients.
Cronbach's alpha
This is the assessment of reliability using responses at only one point in time. Because all items measure the same variable, they should yield similar or consistent results.
Internal consistency
A measure has this if research shows that scores on the measure do in fact predict the behavior or outcome it is intended to predict.
Predictive validity
This form of measurement includes variables with no numerical or quantitative value; they are instead categorical.
Nominal scales
This is the number that assesses the statistical stability of a measure by indicating how strongly two variables are related.
Correlation coefficient
The extent to which two people's ratings of a behavior agree on their observations. Commonly measured using Cohen's kappa.
Interrater reliability
This type of validity would be demonstrated in a study of whether two or more groups of people differ on the measure in expected ways, or by studying how people who score either low or high on the measure behave in different situations.
Concurrent
The letter grading system is an example of one of these measurements, where categories are ranked, though we do not know the distance between categories.
Ordinal scale
This represents a reliable measurement, free of measurement error, though it may not be known since it cannot be measured effectively.
True score
This occurs when there is a discrepancy between the true score and the measured score, making the measurement unreliable.
Measurement error
This is the extent to which scores on the measure in question are related to scores on other measures of the same construct or similar constructs.
Convergent Validity
In this measurement, the distances between numbers on the scale are meaningful and equally distanced.
Interval scale
The difference between a true score and an observed and measured score.
Measurement error
This reliability indicator helps avoid artificially high correlations by administering two different forms of the same test to the same individuals at two points in time, though it requires more time and effort.
Alternate forms reliability
This is demonstrated when scores on the measure are not related to other measures that are theoretically different.
Discriminant validity
In these scales, zero indicates a lack of measurement. Examples of these measurements include: age, reaction time, and frequency of behaviors.
Ratio
The correlation between scores on individual items with the total score on all items of a measure.
Item total correlation