Table 4 .
Breadth of coverage for variable length CAT, fixed length CAT, 8-item short form, and full item bank
| Mode | N | T score |
Standard error |
||||
|---|---|---|---|---|---|---|---|
| Mean ± SD | Range | % Ceiling | % Floor | Mean ± SD | Range | ||
| Variable-length CAT (min 4) | 716 | 50.45 ± 9.57 | 18.86–70.07 | 5.03% | 0.14% | 0.307 ± 0.067 | 0.248–0.529 |
| Variable-length CAT (min 8) | 716 | 50.45 ± 9.58 | 18.86–70.07 | 5.03% | 0.14% | 0.275 ± 0.083 | 0.190–0.529 |
| 8-Item fixed-length CAT | 716 | 50.48 ± 9.58 | 20.16–68.90 | 6.42% | 0.56% | 0.286 ± 0.096 | 0.190–0.543 |
| 8-Item short form | 716 | 50.25 ± 9.05 | 21.30–63.90 | 14.94% | 0.28% | 0.327 ± 0.116 | 0.21–0.57 |
| Full bank | 716 | 50.36 ± 9.65 | 18.50–70.80 | 4.33% | 0.14% | 0.216 ± 0.089 | 0.140–0.510 |