Influences of presentation format and task instruction on children’s number line estimation

Abstract

There is an ongoing debate on how to interpret estimation patterns in the number line (NL) estimation task. One account proposes that children use start-, mid- and endpoints of the NL as references to apply proportion-based strategies for solving the task.In the current study we evaluated the impact of explicitly instructing the midpoint of the NL and varying target placement (middle vs. left end of the NL) on second-grader’s NL estimation performance in a familiar number range (0–100).Our findings indicated that target placement above the middle of the NL not only led to better NL estimation accuracy but also promoted children’s application of proportion-based strategies. In contrast, we did not observe a reliable effect of explicit midpoint instruction.Taken together, our findings add to previous evidence on factors influencing NL estimation performance by revealing the importance of aspects of task presentation.