Table 3.
Average Relative Biases and RMSEs of Item Parameter Estimates and Standard Errors (SE) in Simulated Data
| No. of traits | Est. method | Keyed direction | Estimate intertrait correlations | Est. time (min) | Discrimination | Intercept | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Estimate | SE | Estimate | SE | |||||||||||||
| Rel. bias | RMSE | Percent inestimable (%) | Rel. bias | RMSE | Rel. bias | RMSE | Percent inestimable (%) | Rel. bias | RMSE | |||||||
| 5 | QMCEM | Same | Y | 34 | .00 | .24 | 0 | .03 | .05 | −.01 | .14 | 0 | .13 | .06 | ||
| N | 29 | .00 | .26 | 0 | .08 | .06 | −.01 | .14 | 0 | .12 | .05 | |||||
| Mixed | Y | 37 | .00 | .22 | 0 | .03 | .06 | −.01 | .15 | 0 | .11 | .07 | ||||
| N | 31 | .00 | .28 | 0 | .07 | .06 | −.01 | .16 | 0 | .10 | .07 | |||||
| MHRM | Same | Y | 52 | .00 | .14 | 11 | −.09 | .07 | .00 | .14 | 6 | −.08 | .07 | |||
| N | 51 | .00 | .14 | 9 | .00 | .07 | .00 | .14 | 6 | −.03 | .07 | |||||
| Mixed | Y | 54 | .00 | .14 | 13 | .19 | .10 | .01 | .15 | 8 | .08 | .09 | ||||
| N | 54 | .00 | .14 | 9 | .05 | .08 | .01 | .15 | 6 | .01 | .08 | |||||
| 15a | QMCEM | Same | N | 354 | −.02 | .55 | — | — | — | .02 | .33 | — | — | — | ||
| Mixed | N | 370 | −.01 | .56 | — | — | — | .03 | .36 | — | — | — | ||||
| MHRM | Same | N | 1270 | .00 | .17 | 10 | −.11 | .10 | −.01 | .16 | 5 | −.08 | .11 | |||
| Mixed | N | 890 | .00 | .19 | 4 | −.09 | .11 | .01 | .17 | 2 | −.04 | .12 | ||||
Note. — = Standard errors of item parameters were not estimated in this condition due to extremely long run time.
a
Intertrait correlations were fixed in this condition due to estimation difficulty.