The formula [image omitted] is closely related to combinatorics through an elementary geometric exercise. This approach can be expanded to the formulas [image omitted], [image omitted] and [image omitted]. These formulas are also nice examples of showing two approaches, one algebraic and one combinatoric, to a problem of counting. (Contains 6…

In practice, the sum of the item scores is often used as a basis for comparing subjects. For items that have more than two ordered score categories, only the partial credit model (PCM) and special cases of this model imply that the subjects are stochastically ordered on the common latent variable. However, the PCM is very restrictive with respect…

J. S. Bowers, M. F. Damian, and C. J. Davis (2009) critiqued the computational model of serial order memory put forth in M. Botvinick and D. C. Plaut (2006), purporting to show that the model does not generalize in a way that people do. They attributed this supposed failure to the model's dependence on context-dependent representations,…