Abstract | Roughly a decade ago appeared the Additive Factor Model (AFM), a cognitive diagnostic model that was subsequently implemented by PSLC-Datashop and successfully used by researchers since then. While powerful, this model is not always simple to apprehend for a novice user. This paper aims at addressing this concern, by sharing our understanding of the model and the way we implemented it while conducting research on Q-matrices evaluation. Situating AFM as a member of the multidimensional Item Response Theory models, this paper provides readers with several considerations regarding the behavior of the model and the meaning of its parameters, as well as details on the technical implementation. Finally a use case is presented showing how the model can be used to monitor, understand and improve learning. |
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