Cognitive development of duration and distance in moving stimuli.

为什么儿童很难比较两个移动物体的持续时间或距离？这三年来的研究结果表明：1.对于学龄前儿童和小学低年级儿童来说，当空间点“不同”时，很难正确识别时间起点或时间终点的“相同”或“不同”。他们中的大多数人无法学会操作知识“持续时间=时间停止点-时间开始点”（知识α）来解决这类问题。远处，结果也差不多。2.对于大多数小学高年级的学生来说，最大的问题是他们虽然能够学会使用知识，但却无法意识到使用知识，似乎“持续时间/距离/速度”（知识beta）比知识alpha更容易激活。在远处，结果几乎是一样的。3.初中生能根据任务类型使用足够的知识（知识α或知识β）的人数很少。他们中的大多数人似乎更有可能使用不完整版本的知识测试版，也就是“持续时间=距离”，而不是知识alpha。4.大部分大学生更倾向于使用知识alpha而不是知识beta。只有20%的学生能够根据任务类型正确使用这两种知识。这些发现表明，持续时间和距离的记忆在儿童时期逐渐发展，从青少年早期到青少年末期可能会发生剧烈变化。

Why is it difficult for children to compare lengths of duration or distance for two moving objects? Findings of our studies for these three years show the following. 1. For preschoolers and lower graders in elementary schools, it was not easy to recognize correctly "the same" or "different" of the temporal starting points or the temporal stopping points, when the spatial points were "different". Most of them could not learn to operate the knowledge "duration = temporal stopping point - temporal starting point" (Knowledge alpha) to solve these kinds of problems. In the distance, the results were almost the same. 2. For most of higher graders in elementary schools, the largest problem was that they could not be aware of using the knowledge, though they could learn to use it. It seemed that the knowledge "duration distance/speed" (Knowledge beta ) was more easily activated than Knowledge alpha. In the distance the results were nearly the same. 3. There were few junior high school students who can use the adequate knowledge (Knowledge alpha or Knowledge beta) according to the types of tasks. Most of them seemed to be more likely to use an incomplete version of Knowledge beta, that is "duration = distance" than Knowledge alpha. 4. Most of undergraduates were more likely to use Knowledge alpha than Knowledge beta. Only 20% of them could properly use the two kinds of knowledge according to the type of tasks. These findings suggest that recognitions of duration and distance develop gradually through childhood and there may be a drastic change from the early teen to the end of teen.