Depression, Anxiety and Stress (DASS-21)
In addition to investigating the general health of the learner, it is also necessary to understand the emotional state of the learner and to investigate the emotional state and stress of the learner. Borrowing the Depression Anxiety Stress Scale (DASS) measurement tool, developed and designed by Lovibond & Lovibond (1995), to investigate the impact of the pandemic on the emotional state and stress of learners. DASS-21 involves 3 dimensions and contains 21 items. It has a wide range of applications in the field of mental illness measurement. It is mainly used to diagnose depression, anxiety, and stress. At present, DASS-21 has been translated into 42 versions of different countries. The reliability and validity of the questionnaire are relatively high and the reliability is high. The internal consistency is about 0.89~0.93 (Lovibond & Lovibond, 1995; Henry & Crawford, 2005 ), the internal consistency in the study of Bibi, Lin, Zhang & Margraf (2020) is 0.70 to 0.90. In other language versions of DASS-21, such as the Latin American version of DASS-21, the internal consistency is between 0.88 and 0.90 (González-Rivera, Pagán-Torres & Pérez-Torres, 2020), and in the Hispanic version of DASS The internal consistency of -21 is 0.96 and high construct validity (Daza, Novy, Stanley & Averill, 2002). It can be seen that the DASS-21 scale has high reliability and validity, and has been widely used and verified in a multicultural context. As a result, the study used the DASS-21 scale to investigate the emotional state of online learners during the pandemic and its interaction with web-based learning tool evaluation, self-efficacy, mental health, and family life quality, its reliability is 0.959.