In this ITEMS module, we introduce the generalized deterministic inputs, noisy "and" gate (G-DINA) model, which is a general framework for specifying, estimating, and evaluating a wide variety of cognitive diagnosis models. The module contains a nontechnical introduction to diagnostic measurement, an introductory overview of the G-DINA model, as well as common special cases, and a review of model-data fit evaluation practices within this framework. We use the flexible GDINA R package, which is available for free within the R environment and provides a user-friendly graphical interface in addition to the code-driven layer. The digital module also contains videos of worked examples, solutions to data activity questions, curated resources, a glossary, and quizzes with diagnostic feedback.