. Author manuscript; available in PMC: 2013 Feb 1.

Published in final edited form as: J Exp Child Psychol. 2011 Sep 25;111(2):212–229. doi: 10.1016/j.jecp.2011.08.012

Table 5.

Growth in Fraction Skills Explained by Fourth Grade Predictors (standard errors in parentheses).

	Word Problem		Estimation
Step and predictor	B(SE)	Total R²	B(SE)	Total R²
1a. Autoregressor	.73(.07)***		.44(.05)***
1b. Word reading	.06(.02)**		.18(.06)***
1c. Estimated IQ	.04(.02)*	.61***	.13(.06)*	.32***
2a. Dummy1	−2.31(.70)***		−3.06(.59)***
2b. Dummy2	−1.83(.66)		−1.35(.60)***
2c. Dummy3	−1.39(.42)***	.65***	−.81(.63)	.39***

Note: Autoregressor refers to the same variable as the criterion measured in fourth grade. B refers to regression coefficient. Our procedural knowledge variable used in the cluster analysis was fraction computation. Dummy1 represents the contrast between lower concepts and the higher concepts/higher procedures cluster. Dummy2 represents the contrast between lower concepts/higher procedures and the higher concepts/higher procedures cluster. Dummy3 represents the contrast between higher concepts/lower procedures and the higher concepts/higher procedures profile cluster.