ISSN 0439-755X
CN 11-1911/B
主办:中国心理学会
   中国科学院心理研究所
出版:科学出版社

心理学报 ›› 2010, Vol. 42 ›› Issue (05): 569-580.

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儿童数字估计中的心理长度

莫 雷;周广东;温红博   

  1. (1华南师范大学心理应用研究中心, 广州 510631) (2北京师范大学教育学部, 北京 100875)
  • 收稿日期:2009-03-30 修回日期:1900-01-01 出版日期:2010-05-30 发布日期:2010-05-30
  • 通讯作者: 莫雷

Mental Distance in Children’s Numerical Estimation

MO Lei;ZHOU Guang-Dong;WEN Hong-Bo   

  1. (1 Center for studies of Psychological Application, South China Normal University, Guangzhou 510631, China)
    (2 Division of Education, Beijing Normal University, Beijing 100875, China)
  • Received:2009-03-30 Revised:1900-01-01 Published:2010-05-30 Online:2010-05-30
  • Contact: MO Lei

摘要: 从儿童对数字属性的认识角度探讨一年级儿童在不同数字范围中采用不同表征形式的根本原因。两个实验均采用数字线估计任务, 实验一测量一年级儿童在15cm数字线长度下0~100与0~1000两种范围上的数字估计; 实验二测量一年级儿童对0~1000范围10cm和20cm数字线长度的估计。结果显示, 无论在不同的数字范围还是在不同的数字线长度下, 儿童对低端数字的估计均存在心理长度, 即儿童倾向于将低端数字与固定的线段长度对应起来, 且这种对应关系不随数字范围与数字线长度的变化而变化。心理长度的存在是儿童在不同数字范围和不同数字线长度中采用不同数字表征形式的根本原因, 也是儿童对数概念的认识发展到等距水平时出现的一种独特特点。

关键词: 心理长度, 数字估计, 对数表征, 线性表征

Abstract: Numerical estimation is a pervasive process, both in school and in everyday life. Because of the ease of use and good ecological validity, the number line estimation task becomes of the most popular paradigms in the researches on number estimation. In this task, participants are required to estimate the placement of numbers on number lines. Some of the lines start at 0 and end at 100, whereas others have start point of 0 and endpoint of 1000. In both conditions, the lines were unmarked between the start point and endpoint. The second-year primary school students of America and the first-year students of China manifested the same behavioral patterns in the number line estimation tasks: they both depended on linear representations on 0-100 context while depended on log representations on 0-1000 context. In the current study, we aimed at investigating why the junior year primary school students use different types of number representation for different context. We hypothesized that the reason behind is that they trend to map low end number with fixed distance during number estimation, which is defined as mental distance.
Two experiments were correspondingly designed to examine whether mental distance exists in children’s number estimation. In experiment 1, we examined whether the children used fixed distance to represent low end numbers when the actual length of the number lines were the same while the scale of the numbers varied. Twenty-six first-year primary school students were randomly selected. They were asked to estimate the placement of numbers on 15cm number lines with two contexts: 0-100 or 0-1000. By contrast in experiment 2, we examined whether the children used fixed distance to represent low end numbers when the scale of the numbers were the same while the actual length of the number lines varied. Thirty new first-year students were selected. They were asked to estimate the placement of numbers 0-1000 on number lines with two line lengths: 10cm or 20cm. The low end numbers were oversampled to maximize discriminability of logarithmic and linear functions, and to examine whether mental distance exists.
Paired t-tests of low end numbers showed that there was no significant difference for nine of the ten comparisons on different contexts in experiment 1 and all ten comparisons on different number line lengths in experiment 2. These results suggested that first-year students mapped the low end numbers with fixed distance. Although the context varied from 0-100 to 0-1000, and the lengths of the number lines varied from 10cm to 20cm in the two experiments, the mental distances that low end numbers were mapped to remained constant. Mental distance thus exists in children’s number estimation, and it determines the selection of number representations for different number contexts and number line lengths.
The two experiments came to the same conclusion: mental distance in children’s number estimation is the possible reason why children depend on different representations on different number contexts. Mental distance is a special characteristic emerging when the development of numerical concept in children has reached the interval level.

Key words: mental distance, numerical estimation, linear representation, logarithmic representation