儿童数字估计的表征模式与发展

探讨中国儿童数字估计的表征模式与发展趋势。包括两个实验,均采用数字线估计任务,实验一以92名幼儿园、一年级及二年级儿童为被试,考察其在0~100范围的数字估计,结果显示,幼儿园儿童在数字估计更多地采用对数表征,而一二年级的儿童在数字估计中更多地采用线性表征;实验二以86名一、三、五年级儿童为被试,考察其在0~1000范围的数字估计,结果显示,一年级儿童有一半采用对数表征,另一半采用线性表征,而三五年级儿童大多采用线性表征。中国儿童的数字估计表现出与美国儿童相同的发展模式,都是由不精确的对数表征逐步向精确的线性表征发展;人的数表征有多种形式,即使在同一年龄阶段,也会因任务难度的不同而选择不同的表征模式。中国儿童精确数字估计能力的出现要早于美国儿童。

Representational Patterns of Numerical Estimation and its Development in Children

Two experiments examined the development of children's numerical estimation and representations that gave rise to their estimates.In experiment 1,92 children from kindergarten,grade one and grade two were asked to estimate the locations of numbers on number lines with 0 at one end and 100 at the other and no markings in between.The result of experiment 1 indicated that most kindergarteners produced estimates consistent with a logarithmic function;most first and second graders produced estimates consistent with a linear function.In experiment 2,86 children from grade one, grade three and grade five were asked to estimate the locations of numbers on number lines with 0 at one end and 1000 at the other and no markings in between.There are 26 numbers selected in each experiment.The result of experiment-indicated that about half of first graders produced estimates that were best fit by linear function and half by logarithmic function,the large majority of third and fifth graders produced estimates consistent with a linear function.Both the results were against the view that people rely on any single representation of numbers,but for the Siegler's multiple-representations perspective.Compared with the children in the United States,the Chinese children showed the same development trend as the children in the United States,that is,with increasing age and numerical experience,they rely on appropriate representations increasingly often,but they showed better accuracy in numerical estimation task than their age peers in the United States.