Administration
Assessment of Learning
Basic Testing Definitions
Robert B. Supernaw 2001
MEASURES OF CENTRAL TENDENCY
- Mean - the average value of a set of results
- Median - the midpoint in the distribution of a set of results at which 50% of the results lie above, and 50% lie below
- Mode - the most frequently occurring value in a set of results
- If the M, M, and M coincide, we have a normal distribution of scores
MEASURES OF VARIABILITY
- Range - the distribution of a set of results, including the lowest and highest results
- Deviation - the measure of the deviation of a result from the mean
- Variance - the average squared deviation score
- Standard Deviation - the square root of the variance (68% w/in 1s, 95% w/in 2s)
- What does this mean if we curve the class?
MEASURES OF INDIVIDUAL PERFORMANCE
Z-Scores - the measure of the deviation divided by the standard deviation; that is, the number of standard deviations from the mean
Report Card #1 for John Smith
| Category | Score | Mean |
|---|---|---|
| Pathophysiology of ASHD | 56 | 50 |
| Pharmacology of hypolipemic drugs | 62 | 49 |
| Pharmacotherapy for ASHD | 52 | 55 |
Report Card #2 for John Smith
| Category | Score | Mean | Z-Score |
|---|---|---|---|
| Pathophysiology of ASHD | 56 | 50 | +2.2 |
| Pharmacology of hypolipemic drugs | 62 | 49 | +0.8 |
| Pharmacotherapy for ASHD | 52 | 55 | -1.3 |
- True scores vs. observed scores
- True score - average observed scores for an individual for an infinite number of tests
- Error of Measurement - Difference between an individual's true score and observed score
- Standard Error of Measurement - error standard deviation mean for true scores for a group (68% likelihood of TS in 1 SEM; 95% likelihood in 1.96 SEM)
TEST CONSTRUCTION
- Norm-referenced measurement - score comparisons with others taking the test
- Criterion-referenced measurement - scores on an absolute measure of performance
- Cut-score - point at which a student has demonstrated minimal mastery, below which the student has demonstrated lack of mastery