Dr. Cicchetti is a psychological methodologist and research collaborator who has made numerous biostatistical contributions to the development of major clinical instruments in behavioral science and medicine, as well as the application of state-of-the-art techniques for assessing their psychometric properties. A number of these instruments have become standards in the field, such as the revised Vineland Adaptive Behavior Scales (2005, 2006, 2008), with Sara Sparrow; the SCID-D for assessing dissociative disorders, with Marlene Steinberg; the Yale Acute Observation Scales for assessing the observed health status of febrile infants, with Paul McCarthy; the Neuropsychology Behavior and Affect Profile, for assessing personality changes in right and left hemisphere stroke with Linda Nelson and Paul Satz; and the AIDS Scale for Kids (ASK), with David Schonfeld and colleagues.

He has also conducted important work on the validity of clinical and neuropsychological scales for adults and children, and on the creation of computer programs for: identifying ordinal trends with dichotomous outcomes;assessing specific category rater agreement for qualitative data; estimating the reliability and systematic bias of individual measurements; testing the reliability of nominal scales using multiple raters; correlating variables when one is measured on an ordinal and the other on a continuous scale; estimating the significance of the difference between two Kappa or Weighted Kappa statistics; and for conducting meta-analyses, especially when outcome variables are dichotomous.

Dr. Cicchetti has also written extensively on the use of multiple comparison procedures; the development of measures of agreement when multiple examiners assess a single case and methods for detecting and distinguishing between reliable and unreliable judges (Cicchetti, Bronen, Spencer, Haut, Berg, Oliver, & Tyrer,2006); identifying and resolving paradoxes that can occur in the application of the kappa statistic; determining optimal numbers of scale points when the variable has an underlying metric; and the assessment of the reliability and validity of a wide range of diagnostic systems in both behavioral science and medicine.

He has published collaborating on research investigating the reliability and validity of female teenager’s reports of sexually transmitted diseases, with Linda Niccolai, Jeannette Ickovics, and other CIRA colleagues (2005).

The second edition of his biostatistical text (Cicchetti, D.V. and Rourke, B.P. (2004) was recently published by Psychology Press, Taylor & Francis, London, UK, and is entitled "Methodological and Biostatistical Foundations of Clinical Neuropsychology and Medical and Health Disciplines."

In August, 2006, Dr. Cicchetti was awarded the Honorary rank of Fellow in the American Statistical Association for his outstanding contributions in behavioral and medical statistics, particularly assessment of psychometric properties of clinical diagnostic instruments, and for innovative methodologies for interexaminer reliability assessments.