Why count stuff? Young preschoolers do not use number for measurement in continuous dimensions

Abstract

Adults routinely use numbers to make precise references to amounts of substance (e.g. 5 liters of water), but the ontogenesis of this capability is poorly understood. We developed a new method for addressing this issue. This report focuses on children's ability to conceive of measuring substances by drawing on numerical information. Three-to 5-yearolds are unable to use even small differences of number to facilitate the quantitative comparison of small portions of sand. It is argued that children are biased to enumerate objects and to measure substances without counting.

Quantitative competencies in infancy

“…Such results suggest that numerical discriminations are actually relatively easier than discriminations of continuous extent for the infant. These findings are also consistent with findings that preschoolers have greater difficulty discriminating the amount of continuous substance than the number of items (Huntley‐Fenner, 2001).…”

Child proportional scaling: Is 1/3=2/6=3/9=4/12?

“…On the majority of trials, participants produced responses that fell on the wrong line rather than on the correct line, resulting in increased proportional error relative to the continuous condition. This tendency may be related to children's difficulty in unitizing continuous quantities (Huntley-Fenner, 2001;Sophian, 2007). This is also particularly interesting because adults presumably would exploit the additional precision that the demarcating lines afford and would be even more likely to produce responses with minimal proportional error in the discrete condition than in the continuous condition.…”

Tracking and quantifying objects and non‐cohesive substances

“…These few studies represent virtually all of the work investigating infants’ ability to quantify substances (see Huntley‐Fenner, 2001, for related work with preschoolers). One possible explanation for the discrepant findings is that the ratio between the ‘expected change’ and ‘no change’ outcomes was more discriminable (1:3) in the Gao et al .…”