Table 4.
T values for planned comparisons between experimental conditions
| Percentage of correct responses | Response speed | |
|---|---|---|
| The three of the four easiest conditionsa | ||
| Dots-Congruent vs. two-Abstract-Shapes | ||
| All subjects (d.f. = 1,313) | 13.52 | −19.78 |
| Younger subjects (4–6 years; d.f. = 1,89) | 12.54 | −26.91 |
| Older subjects (6–26 years; d.f. = 1,223) | 5.72 | −6.29 |
| Dots-Congruent vs. Pictures | ||
| All subjects (d.f. = 1,313) | 13.20 | −24.00 |
| Younger subjects (4–6 years; d.f. = 1,89) | 13.91 | −27.84 |
| Older subjects (6–26 years; d.f. = 1,223) | 4.23 | −10.31 |
| The three hardest conditionsb | ||
| Dots-Mixed vs. six-Abstract-Shapes | ||
| All subjects (d.f. = 1,313) | −6.24 | 2.46 (p < 0.01) |
| Younger subjects (4–6 years; d.f. = 1,89) | −4.22 | 1.30 NS |
| Older subjects (6–26 years; d.f. = 1,223) | −4.78 | 2.24 |
All significant at p < 0.0001, unless otherwise noted.
Dots-Incongruent was the other very easy condition. For performance on Dots-Congruent vs. Dots-Incongruent, see Table 3. Accuracy on two-Abstract-Shapes, Pictures, and Dots-Incongruent was fully comparable. Response speed was faster on two-Abstracts-Shapes than on Pictures (all three comparisons significant at p < 0.0001) and on Dots-Incongruent than Pictures (for all subjects and older subjects, p < 0.0001; for younger subjects, p = 0.06). Younger children were faster on Dots-Incongruent than two-Abstract-Shapes (t[89] = 3.54, p < 0.001), while our older subjects were faster on two-Abstract-Shapes than on Dots-Incongruent (t[223] = −2.46, p < 0.02).
Arrows was the other relatively difficult task. For Dots-Mixed vs. Arrows, see the section comparing performance in the three Mixed conditions. There were no significant differences in either speed or accuracy on six-Abstract-Shapes and Arrows.