. Author manuscript; available in PMC: 2020 Apr 1.

Published in final edited form as: J Exp Psychol Gen. 2019 Apr;148(4):739–762. doi: 10.1037/xge0000581

Table 7.

Experiment 2 Descriptive Statistics for all Measures

	Measures	n	M	SD	Range	Skew	SE_Skew	Z_Skew	Kurtosis	SE_Kurtosis	Z_Kurtosis
Self-Derivation	Open-ended	57	1.49	1.50	0–4	.48	.32	1.51	−1.30	.62	−2.08^*
Self-Derivation	Forced-choice	57	3.05	1.04	1–4	−.79	.32	−2.51^*	−.57	.62	−.92
Cognitive Measures	Verbal Comprehension	57	52.77	6.54	39–68	.08	.32	.24	−.47	.62	−.76
	TONI₄	57	24.67	5.31	15–38	−.04	.32	−.13	−.16	.62	−.25
	Backward Corsi	57	25.65	15.63	0–72	.63	.32	1.99^*	.34	.62	.55
Academic Measures	RI -Concurrent	56	606.68	250.24	0–1180	−.44	.32	−1.38	.35	.63	.56
	RI- Longitudinal	43	906.16	222.13	554–1369	.12	.36	.34	−.82	.71	−1.16
	EOG math - Concurrent	55	446.15	9.30	428–469	.05	.32	.17	−.70	.63	−1.11
	EOG math - Longitudinal	43	450.12	8.53	434–469	.00	.36	.00	−.54	.71	−.76

Note:

denotes p < .05. TONI₄ = relational reasoning; Backward Corsi = working memory. Reading comprehension as measured by Reading Inventory (RI), range 0–2000 across grades K-12, expected range for Grade 3 is 415–760 and Grade 5 is 770–1080. Mathematics as measured by NC end-of-grade test (EOG), range 425–470 within grade.