Strategy for Offering Test Questions Based on the Relationship between the Representation of Calculation Questions and their Difficulty

The authors have been developing a calculation question training system that aims to improve university and college students' calculation abilities. The difficulty of calculation questions seems to depend mainly on the complexity of the calculation formula and its solution. However, we have confirmed that the representations of calculation questions can affect the rate of correctness of answers, even when the solutions use the same calculation formula. Against this background, our question training system extracts questions adapted to the students' ability from a question database and offers them to the student. The question database stores many questions with different representations, even though they are solved using the same or similar formulas. In this paper, we discuss some experiments executed at our university, the relationship between the representation of calculation questions and their difficulty, and the strategy for offering questions for the calculation question training system. (C) 2016 The Authors. Published by Elsevier B.V.