Calibrating items with time use diaries: A refined method

The aim of the article is to refine a calibration method already presented and used to improve the information provided by the scales of frequency in questionnaires by combining it with data from time use diaries. In other words, this study proposes improvements to an existing calibration method aiming at “adjusting” the data gathered through items — which is useful for the analysis of phenomena with relatively long time cycles, but also notoriously subject to bias — with the data gathered through daily diaries — which are less subject to distortion, but generally only suitable for analysing phenomena with short or very short time cycles. In some cases, in fact, the calibration model already proposed may be problematic since, as we shall see, it could introduce another possible cause of bias. Such distortion could become relevant in certain situations and can be remedied by the proposed refinement with the new calibration model under consideration here. Finally, to highlight the advantages of the proposed method, we will develop with practical applications, comparisons by applying the presented models on data on religious practice collected in a large survey conducted in Italy in 2008. It should be specified, however, that the applicability of the proposed model is not limited to this example and can be extended to other contexts and types of data.