A focus on issues related to clinical assessment has led Dr. Kamphaus to pursue research in classification methods, differential diagnosis, test development and learning disability and ADHD assessment. He has served as principal investigator, coinvestigator, or consultant on several federally funded research projects dealing with early intervention and prevention, child classification methods, prevalence of ADHD and Conduct Disorder in Latin America, and violence prevention in schools.

As a licensed psychologist and a Fellow of the American Psychological Association (APA), he has contributed extensively to his profession, and he is Past-President of the Division of School Psychology for APA. Dr. Kamphaus has also authored or coauthored 5 books, 2 psychological tests, more than 40 scientific journal articles, and more than 20 book chapters. He also participates in scholarship in the field through work as an editorial board member, associate editor, test reviewer, and newsletter editor. Dr. Kamphaus is a frequent guest lecturer and speaker.