This book provides an introductory view to a Bayesian approach for assessing effort in the context of neuropsychological evaluation. Within psychology, Bayesian models have been widely used in data analysis for functional neuroimaging research on different cognitive functions, human inductive learning and memory. Given the complexity of malingering and effort determination, the present work aims at contributing to the improvement of the existing effort assessment techniques. The present book includes a theoretical background about malingering, a brief description of Symptom Validity Testing (SVT) and an overview of Bayesian methods applied to the field of effort assessment. It also includes some preliminary findings of the utility of a Bayesian latent group model in malingering research, stating its clinical relevance, limitations and further directions.