1. Psychological Testing
Characteristics of Psychological Testing 13.1

2. Characteristics of Psychological Tests
Must exhibit reliability, validity, and standardization to be useful
Fairness and usefulness of a test depend on
Reliability
Test’s consistency
Same results under variety of differing circumstances
Three basic ways to determine reliability
Test-retest
Interscorer-scorer
Interscorer- different test graders
Scorer- same test grader
Split-half
Dividing test items in half and scored separately

3. Validity Standardization
Ability of a test to measure what it is intended to measure
Chief method for measuring validity is to find out how well a test predicts performance- predictive validity
A test designed for measuring management ability
Will the people who score high make good managers?
Standardization
Administered and scored same way every time
Refers to establishing the norm, or average score, for a large group

4. Why must raw scores be transformed into percentiles?
Percentile system
Ranking of test scores that indicate the ratio of scores lower and higher than a given score
Scores actually achieved are ranked in order from highest to lowest
Each score is compared with list and assigned percentile according to the percentage of scores that fall above or below this point
Child scores 32/50 on a vocabulary test
How does this relate to other children that were tested
If most children scored 45/50, then score is low; 20/50, then score is high
If 32 were the top score, then it would be in the 100th percentile
If half the children scored 32 or below, then 32 is in 50th percentile
Therefore, a raw score must be transformed into percentiles because it does not indicate where the student ranks among the students who took the same test