Clinimetrics is a methodological discipline with a focus on the quality of measurements in medical research and clinical practice. The quality of measurements includes both the quality of the measurement instruments and the quality of the performance of the actual measurements The clinimetrics group consists of a group of excellent and very active researchers in the field of Clinimetrics. Their activities are embedded in the Knowledgecenter Measurement Instruments of the VU University Medical Center, and in the Section Measurement of the Department of Epidemiology & Biostatistics, Vu University Medical Center, Amsterdam. The Clinimetrics group was founded in 2002 with the appointment of Henrica C.W. de Vet as Professor in Clinimetrics.