The psychometric qualities of measurement instruments in diary studies: An illustration on the basis of the work engagement scale

Despite the emerging popularity of diary studies, until now little attention has been paid to the psychometric properties of measures used in diary studies. When the time frame of questionnaires in diary studies is adapted, it is important to examine whether the factor structure remains the same. The aim of this article is to introduce a method to examine the factor structure of daily variables. This method will be illustrated by performing a multilevel confirmative factor analysis on the questionnaire used to measure daily work engagement. The results showed that daily work engagement can be measured by adapting the time frame of the questionnaire to measure enduring work engagement, although it is eligible to replace one of the nine items.