CDM Notations

The response vector of examinee i will be denoted by
Yi,i=1,2,...,N
The response vector contains J items, as in,
Yi=(Yi1,…,Yij,…,YiJ)
The attribute profile of examinee i will be denoted by
αi=(αi1,…,αiK)
Each attribute vector or profile defines a unique latent class. For
latent class c, we have
αc=(αc1,…,αcK)
Thus, K attributes define 2K latent classes