Kirkwood, M. W. (Ed.) (2015). Validity Testing in Child and Adolescent Assessment: Evaluating Exaggeration, Feigning, and Noncredible Effort. … See the original post: Kirkwood, M. W. (Ed.) (2015). Validity Testing in Child and Adolescent Assessment: Evaluating Exaggeration, Feigning, and Noncredible Effort.