This study aimed to describe 1-year changes in students' vocabulary in written narratives. Secondary aims included examination of accuracy and the relationship between lexical diversity and achievement. Participants included 749 students in first through eighth grades. Within-subjects 1-year change in diversity, productivity, and accuracy was…

In an intelligent tutoring system (ITS), it can be useful to know when a student has disengaged from a task and might benefit from a particular intervention. However, predicting disengagement on a trial-by-trial basis is a challenging problem, particularly in complex cognitive domains. In the present work, data-driven methods were used to address…