. Author manuscript; available in PMC: 2024 Jan 26.

Published in final edited form as: Dev Psychol. 2012 Mar 5;48(5):1229–1241. doi: 10.1037/a0027433

Table 2.

Correlations Between Tasks in Study 1 (N = 152)

Assessment point and task	1	2	3	4
Beginning-of-year scores
1. Number line knowledge (0–1,000 number line linear R²)^a	—
2. Spatial skill (Thurstone mental rotation; items correct of eight)	.25^**	—
3. Math achievement (WJ-III Applied Problems W score)	.23^**	.20^*	—
4. Reading achievement (WJ-III Letter-Word Identification W score)	.24^**	.17^*	.63^***	—
End-of-year score
5. Number line knowledge (0–1,000 number line linear R²)^a	.32^***	.27^**	.38^***	.22^**

Note. WJ-III = Woodcock-Johnson III Tests of Achievement.

These variables have been transformed using an arcsine transformation {2 × asin[sqrt(x)]}.

p < .05.

^**

p < .01.

^***

p < .001.