Identification of behavioral variables for efficient representation of difficulty in vocabulary learning systems

Abstract

This study focuses on foreign language vocabulary learning in computerized medium and seeks behavioral variables that best reflect the difficulty level of learning material. In this respect, we employ a spaced repetition flashcard software and display English vocabulary belonging to various word classes as well as difficulty levels to a set of participants and determine the most efficient variables in representation of task difficulty and estimation of required effort. Based on an analysis of activity logs, we propose a set of behavioral variables, which have a potential relation to task difficulty. Subsequently, we examine the correlation between these behavioral variables and task difficulty levels. Our results indicate that variables at deck level have a stronger relation to difficulty than those at card level. In addition, when the correlation of the proposed variables with the difficulty level is contrasted to users' self assessment of difficulty, the proposed variables are found to be more reliable indicators of difficulty. Such variables are promising for improving the performance in user-adaptation, scheduling of learning tasks, and estimation of learning effort, motivation and engagement among others.