Lechner, Clemens M., Nivedita Bhaktha, Katharina Groskurth, and Matthias Bluemke. 2021. “Why Ability Point Estimates Can Be Pointless: A Primer on Using Skill Measures From Large-Scale Assessments in Secondary Analyses”. Measurement Instruments for the Social Sciences 3 (1), Article e11033. https://doi.org/10.1186/s42409-020-00020-5.