Quantitative Estimation: One, Two, or Three Abilities?

Abstract

The mathematics education literature refers to 3 types of quantitative estimation skill: numerosity, measurement, and computational estimation. The psychometric literature includes a confusing array of tests intended to define quantitative estimation. This study examined relations among tests for numerosity, measurement, and computational estimation, and recognized tests for numerical facility and quantitative reasoning using principal components analysis. 2 components were identified. The first component aligned computational estimation with numerical facility and general quantitative reasoning. The second component included the tests of numerosity and measurement estimation. It was suggested that this second component might be related to spatial ability. Implications for mathematics education and assessment are discussed.