Background: Internet psychology services are rapidly increasing and that implies online assessment. To guarantee the results of these new online evaluation procedures, it is necessary to have reliable and valid assessment tools.
Objective: In this work we analyzed the online versions of two popular psychopathology screening questionnaires: the General Health Questionnaire-28 (GHQ-28) and the Symptoms Check-List-90-Revised (SCL-90-R).
Methods: A total of 185 psychology students were recruited from two universities in Madrid, Spain. All of them had Internet access at home. A test-retest situation and factorial analysis were used to generate reliability and validity data. Both paper-and-pencil questionnaires (test) and their online versions (retest) were completed by 100 participants (median gap = 17 days).
Results: Results suggest that both online questionnaires were fairly equivalent to their paper-and-pencil versions, with higher reliability values for the SCL-90-R. Factorial analysis tended to reproduce the structure shown in former investigations of both questionnaires, replicating the four-factor structure of the GHQ-28 but failing to do so with the nine-factor structure of the SCL-90-R. Instead, a large unrotated factor appeared.
Conclusions: Further research should be carried out to confirm these data, but our work supports the online use of both assessment tools. The psychometric properties of the online version of GHQ-28 is similar to the paper-and-pencil and we can recommend its utilization in a Web environment. In contrast, SCL-90-R can only be recommended as a global index for psychological distress, using the Global Severity Index (GSI), not necessarily its subscales; and it should be considered that the online scores were lower than the ones with the paper-and-pencil version.