PAR author David J. Schretlen, PhD, will be giving a workshop at the annual conference of the American Academy of Clinical Neuropsychology (AACN) in Washington, D.C., on June 9, 2011. Dr Schretlen’s workshop, entitled “Threats to the Validity of Inference in Neuropsychology and Novel Methods of Practice to Help Overcome Them,” will encourage participants to consider fundamental questions about inference in clinical psychology: How do we decide when a neuropsychological examination is abnormal? What constitutes “impaired” test performance? When does a set of abnormal test scores represent a clinically meaningful pattern? Dr. Schretlen will describe three basic approaches to clinical inference (pathological signs, deficit measurement, and pattern analysis) and examine the underlying logical assumptions, implementation, strengths, and threats to the validity of each inferential method. Participants will examine the conceptualization and assessment of pathognomonic signs and cognitive deficits and will discuss the risky practice of sysgiving additional tests to clarify ambiguous findings. Dr. Schretlen will describe what it means to “calibrate” test performance for demographic characteristics and estimated premorbid ability, and how this fundamentally alters the meaning of high and low test scores. Participants will learn about the circumstances under which raw scores can be more informative than demographically calibrated scores. Finally, Dr. Schretlen will argue that symptom validity testing differs from effort testing, and he will present findings from an experiment designed to assess cognitive effort among adults with no incentive to feign impairment and no evidence of symptom exaggeration. Dr. Schretlen is Associate Professor of Medical Psychology in the Departments of Psychiatry and Radiology at Johns Hopkins University School of Medicine. He is the author of the Calibrated Neuropsychological Normative System™ (CNNS™) and the companion Software Portfolio (CNNS™-SP), which are designed to assist clinicians and researchers in their interpretation of the tests that make up the normative system. To learn more about how to improve the precision of neuropsychological test interpretation with the CNNS and to see a list of tests calibrated by the CNNS, visit www.parinc.com .