TreeBUGS

User-friendly analysis of hierarchical multinomial processing tree (MPT) models that are often used in cognitive psychology. Implements the latent-trait MPT approach (Klauer, 2010) doi:10.1007/s11336-009-9141-0 and the beta-MPT approach (Smith & Batchelder, 2010) doi:10.1016/j.jmp.2009.06.007 to model heterogeneity of participants. MPT models are conveniently specified by an .eqn-file as used by other MPT software and data are provided by a .csv-file or directly in R. Models are either fitted by calling JAGS or by an MPT-tailored Gibbs sampler in C++ (only for nonhierarchical and beta MPT models). Provides tests of heterogeneity and MPT-tailored summaries and plotting functions. A detailed documentation is available in Heck, Arnold, & Arnold (2018) doi:10.3758/s13428-017-0869-7 and a tutorial on MPT modeling can be found in Schmidt, Erdfelder, & Heck (2022) doi:10.31234/osf.io/gh8md.