  Recent surge of interests in cognitive assessment has led to the developments
of novel statistical models for diagnostic classification. Central to many such
models is the well-known Q-matrix, which specifies the item-attribute
relationship. This paper proposes a principled estimation procedure for the
Q-matrix and related model parameters. Desirable theoretic properties are
established through large sample analysis. The proposed method also provides a
platform under which important statistical issues, such as hypothesis testing
and model selection, can be addressed.
