In this study, we analyzed usages behaviors of 53,825 active users from 12 countries in a mobile app called "English Practice." The data indicated that the app was used most often in the evening from 8 p.m. to 9 p.m., and especially midweek, with less use at weekends and on Mondays. Learners used the app for about 5 minutes each session…

Nine indices of response pattern appropriateness were compared, based on item response theory, with respect to their relation to the total test score and their effectiveness in detecting unusual response patterns. The ability to differentiate between three groups was compared: cooperative examinees, uncooperative examinees, and randomly generated…