Table 1.

Each line of the table reports the results of a separate multiple regression analysis.

	Full model		a (scaling parameter)		b (scaling parameter)		c (exponent)
	R 2	F	beta	t	beta	t	beta	t
Cases in which a correlation is predicted
Reading
Orthographic Decision	0.107	4.84 **	0.17	2.00 *	0.25	2.73 **	0.13	1.42
Spelling
DDO-2: Words with unpredictable mapping	0.093	4.13 **	−0.22	−2.44 *	−0.18	−1.94 *	0.04	0.39
Maths
Arithmetic Facts	0.107	4.85 **	0.21	2.44 *	0.21	2.35 *	−0.03	−0.31
Times Table in Series	0.086	3.80 *	−0.14	−1.63	−0.23	−2.47 **	0.03	0.37
Multiplications	0.131	6.08 ***	−0.25	−2.9 **	−0.23	−2.58 **	−0.04	−0.41
Additions and Subtractions within “10”	0.071	3.08 *	−0.10	−1.11	−0.24	−2.57 **	−0.09	−0.94
Cases in which a correlation is NOT predicted
Spelling
DDO-2: Pseudo-words	0.032	1.31	−0.12	−1.37	−0.11	−1.17	−0.01	−0.08
Maths
Judgment of Number	0.036	1.52	0.08	0.92	−0.19	−1.99*	−0.09	−1.02
Transformation into Digits	0.042	1.77	0.07	0.75	0.05	0.56	−0.17	−1.88
Number Order	0.021	0.85	−0.08	−0.84	−0.10	−1.06	−0.07	−0.79
Dictation of Numbers	0.006	0.15	−0.06	−0.51	0.00	0.01	−0.04	−0.38
Computation Strategies test	0.064	1.75	−0.20	−1.78	−0.13	−1.11	−0.03	−0.28
Cases in which prediction is uncertain
Reading
MT accuracy	0.056	2.37	0.13	1.42	0.14	1.53	−0.09	−0.99
MT speed	0.132	6.13 ***	−0.21	−2.44 *	−0.25	−2.86 **	−0.15	−1.68
One-Minute test	0.090	3.51 *	−0.24	−2.59 **	−0.10	−1.07	0.10	1.02
Spelling
“Nonna Concetta” dictation task	0.125	5.74 ***	−0.17	−2.02 *	−0.23	−2.63 **	0.12	1.35
DDO-2: Regular words	0.056	2.39	0.00	0.03	−0.23	−2.45*	−0.15	−1.60
DDO-2: Words with context-sensitive rules	0.024	0.99	−0.14	−1.50	−0.04	−0.46	−0.04	−0.44
DDO-2: Total accuracy	0.090	4.01 **	−0.19	−2.12 *	−0.21	−2.33 *	−0.03	−0.35
Maths
Written Arithmetic Calculations	0.026	1.09	−0.02	−0.23	−0.16	−1.72	−0.03	−0.33
Arabic Number Reading (total correct)	0.070	3.04 *	−0.19	−2.11 *	−0.10	−1.12	0.12	1.32
Arabic Number Reading (tot. seconds)	0.018	0.74	0.13	1.41	−0.03	−0.34	0.03	0.28
Control tests
Raven Matrices	0.015	0.62	−0.01	−0.06	−0.12	−1.23	0.02	0.21
Digit Span forward	0.005	0.09	0.07	0.48	−0.04	−0.30	−0.03	−0.19
Digit Span back	0.092	1.82	−0.01	−0.07	−0.25	−1.83	−0.21	−1.53

In all cases, the dependent measure is the task in the left column and the predictors entered in the analysis were the parameters of the individuals power fits. For each model, the overall value for R² (and the related F value), the betas connected to the scaling parameter a (asymptotic performance), b (the difference between initial and asymptotic performance), and c (the exponent of the power function) as well as the related Student t values are reported. Significance of F and Student’s t values are indicated by asterisks. Results indicating overall significant predictions are presented in bold. For the organization of the table as a function of the hypotheses of the study see main text.

^* p<0.05.;

^** p<0.01 and

^*** p<0.001