Validity and reliability evidence for the scale of distance education satisfaction of medical students based on item response theory (IRT).

The least informative items were item 23, 24 and 25 in Factor 1, item 3 in Factor 2, and items 13 and 18 in Factor 3. The most informative items of DESS were those that had adaptive, useful expressions that had meaningful content and were able to provide educator support, which are the properties emphasized in the literature with respect to satisfaction with distance education. A measurement invariance test made based on gender revealed that DESS satisfied measurement invariance by meeting the compliance indexes required for configural, metric, scalar and strict invariance as recommended in the literature. The results showed that it is possible to make comparisons on the basis of gender using DESS.