Table 1.

Descriptive statistics for the composition and handwriting fluency variables and effect sizes and significance tests associated with developmental differences between the first- and fourth-grade samples

	1st Grade M (SD)	4th Grade M (SD)	Cohen’s
			D	t
Macro-organization
1. Topic	0.78 (0.41)	0.97 (0.18)	0.56	3.78***
2. Logical ordering of ideas	2.81 (0.94)	3.44 (0.62)	0.80	5.42***
3. Number of key elements	2.00 (0.61)	2.37 (0.55)	0.67	4.46***
Complexity
4. Mean length of T-units	7.07 (2.03)	9.84 (2.10)	0.94	6.36***
5. Clause density	1.25 (0.27)	1.51 (0.29)	0.91	6.24***
Productivity
6. Total number of words	43.77 (18.00)	112.32 (41.09)	2.17	15.04***
7. Number of different words	28.06 (9.71)	62.76 (17.30)	2.48	17.14***
Spelling and punctuation
8. Number of spelling errors	5.99 (5.10)	5.14 (5.08)	0.16	1.09
9. Number of capitalization errors	2.23 (2.23)	1.57 (2.10)	0.28	1.96
10. Number of period errors	1.32 (1.80)	1.05 (1.50)	0.16	1.07
Handwriting fluency
11. Alphabet printing fluency	8.39 (5.02)	22.19 (11.47)	1.65	11.12***
12. Sentence copying fluency	6.98 (3.25)	20.64 (5.73)	2.69	17.08***

^***p < .001