“…There are a lot of IRT specific software packages available, in particular in the programming language R (R Core Team, 2019), for example, mirt (Chalmers, 2012), sirt (Robitzsch, 2019), or TAM (Robitzsch et al, 2019; see Bürkner, 2019 for a detailed comparison). In addition to these more specialized packages, general purpose probabilistic programming languages can be used to specify and fit Bayesian IRT models, for example, BUGS (Lunn, Spiegelhalter, Thomas, & Best, 2009; see also Curtis & others, 2010), JAGS (Plummer, 2013; see also Depaoli, Clifton, & Cobb, 2016;Zhan, Jiao, Man, & Wang, 2019), or Stan (Carpenter et al, 2017; see also Ames & Au, 2018;Luo & Jiao, 2018). In this paper, I will use the brms package (Bürkner, 2017(Bürkner, , 2018, a higher level interface to Stan, which is not focussed specifically on IRT models but more generally on (Bayesian) regression models.…”