INSTd: A Computer-Adaptive Assessment of Definition-Based Comprehension Skills

Abstract

This paper introduces INSTd, a computer-adaptive test designed to assess learners’ ability to interpret dictionary-style definitions and apply them in appropriate contexts. Unlike conventional vocabulary tests that measure already-acquired word knowledge, this test presents definitions and evaluates learners’ ability to acquire new words based on those definitions. We analyzed the correlation of the estimated abilities of INSTd with their vocabulary sizes among 1,221 sixth-grade students. Results show a moderate correlation with vocabulary size (r = 0.343, p < .001), indicating that the test, although related to vocabulary, captures a distinct aspect of reading ability