Challenges in measuring religiosity in longitudinal surveys
This article will attempt to present the difficulties to assess religiousness in international research. From the methodological perspective this issue needs to be considered in a few aspects. First of all – accuracy, the indicators used to assess religiousness traditionally refer for the most part to the external manifestations of commitment, which in the context of the changes undergoing in the religious sphere in our times seem to be insufficient. For they generally grasp the institutional dimension of religiousness, while referring to a smaller extent to individual, private or subjective religiousness as well as spirituality. Secondly, the issue of the reliability of the survey needs to be considered. The queries constituting the indicators of the assessment of religiousness belong to a sensitive sphere. The question is whether the data collected on sensitive topics and the results depend on the administration mode. Thirdly, there is still a relative lack of clear evidence in literature on how valid comparison can be made when we use different data collection modes. In this article, on the basis of religion module data the effects of applying different modes were examined. The results of analysis lead to the conclusion that the variation between countries partly comes from selection effects and partly from mode effects.