| Abstract: | This study sought a scientific way to examine whether item response curves are influenced systematically by the cognitive processes underlying solution of the items in a procedural domain (addition of fractions). Starting from an expert teacher's logical task analysis and prediction of various erroneous rules and sources of misconceptions, an error diagnostic program was developed. This program was used to carry out an error analysis of test performance by three samples of students. After the cognitive structure of the subtasks was validated by a majority of the students, the items were characterized by their underlying subtask patterns. It was found that item response curves for items in the same categories were significantly more homogeneous than those in different categories. In other words, underlying cognitive subtasks appeared to systematically influence the slopes and difficulties of item response curves. |
