Table 1.
Descriptive Statistics
| M | SD | Range | |
|---|---|---|---|
| Down syndrome | |||
| Chronological age | 15.29 | 3.21 | 10.25–21.92 |
| Nonverbal IQ | 44.66 | 8.83 | 36–71 |
| Nonverbal ability (GSV) | 467.46 | 9.94 | 453–492 |
| MCST (learning efficiency score) | 12.00 | 7.10 | 0–30 |
| Concept Formation test (raw score) | 5.12 | 4.15 | 0–16 |
| Intellectual disability | |||
| Chronological age | 15.85 | 2.54 | 10.25–20.67 |
| Nonverbal IQ | 54.20 | 10.18 | 36–77 |
| Nonverbal ability (GSV) | 476.92 | 8.93 | 458–487 |
| MCST (learning efficiency score) | 18.56 | 14.61 | 0–44 |
| Concept Formation test (raw score) | 11.16 | 6.74 | 2–24 |
| Typically developing | |||
| Chronological age | 7.41 | 2.67 | 4.25–13.50 |
| Nonverbal IQ | 97.39 | 13.30 | 76–129 |
| Nonverbal ability (GSV) | 477.18 | 13.18 | 459–498 |
| MCST (learning efficiency score) | 26.11 | 12.25 | 12–45 |
| Concept Formation test (raw score) | 13.64 | 9.37 | 1–34 |
Note. GSV = growth score value; MCST = Modified Card Sort Task.