Simple behavioral memory tests are widely used in clinical settings, as a way of measuring and understanding memory impairment caused by Alzheimer's disease and related disorders. A standard test of episodic memory uses immediate and delayed free recall tasks, in which people have to recall lists of words presented to them. A standard test of semantic memory involves the triadic comparisons of animal names, in which people have to judge the similarities between them. Lee uses an extensive real-world data set of clinical assessments based on these tasks, and develops and applies new cognitive models that measure the underlying psychological properties of episodic and semantic memory for individuals and clinical sub-populations. The theoretical goal is to use real-world data to develop a better understanding of human memory and the effects of impairment. The applied goal is to develop model-based methods for improving the early detection and diagnosis of Alzheimer's disease and related disorders. This is joint work with Holly Westfall (UCI) and Jason R. Bock (Medical Care Corporation).