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Changes in the root mean squared difference (RMSD) of ability using estimated ability across Time 1 and Time 2.
| Condition | RMSD | |
|---|---|---|
| Two-class 2PL mixture IRT | Unidimensional 2PL IRT | |
| 1 | 0.003 | 0.002 |
| 2 | 0.015 | 0.008 |
| 3 | 0.014 | 0.007 |
| 4 | 0.003 | 0.006 |
| 5 | 0.012 | 0.021 |
Simulated with 100 replications using posterior mode estimation. Values in parenthesis represent standard errors.
