This is the fourth in a series of six papers that will be published from the 1999 lecture series on "Quality Assessment in Women's Health Care" held at the University of Michigan School of Public Health. The lectures are presented by leaders in women's health research, and they explore key issues in the definition, measurement, and improvement of quality in women's health services. The series is supported by an unrestricted educational grant from Pfizer Inc. and is presented by the Interdepartmental Concentration in Reproductive and Women's Health at the University of Michigan School of Public Health; the University of Michigan National Center of Excellence in Women's Health; and the Michigan Initiative for Women's Health. The series coordinator is Carol S. Weisman, PhD, and Catherine L. Maroney prepared the summary of the discussants' comments.