The discrimination index measures how effectively a test item distinguishes between high- and low-performing individuals.
| LIST I (Theory) | LIST II (Proposed By) | ||
|---|---|---|---|
| A | ‘g’ Factor Theory | I | Guilford |
| B | Hierarchical Theory | II | Spearman |
| C | Multifactor Theory | III | Vernon |
| D | Cubical Model | IV | Thurstone |