. Author manuscript; available in PMC: 2014 Jan 4.

Published in final edited form as: Cognition. 2007 Jan 8;105(2):10.1016/j.cognition.2006.10.005. doi: 10.1016/j.cognition.2006.10.005

Table 2.

Mean coefficients of variation (COVs) for “four” -knowers, CP non-mappers, and CP mappers.

Knower-level	Set size
	1	2	3	4	6	8	10
“Four”-knowers	0 (0)	0 (0)	0.41 (.16)	0.40 (.14)	---	---	---
CP non-mappers	0 (0)	0.02 (.02)	0.14 (.05)	0.25 (.04)	---	---	---
CP mappers	0 (0)	0 (0)	0.01 (.01)	0.12 (.03)	0.22 (.03)	0.24 (.03)	0.18 (.02)

Note: The coefficients of variation (COVs) in this table were computed as the ratio of the standard deviation of estimates over the mean of estimates for each given set size. The standard error for each COV is indicated in parentheses. “Four”-knowers’ and CP non-mappers’ COVs for large numerals were not computed because these children could not estimate the numerical size of large sets.