Disease Assessment Terms and Concepts. Forrest W. Nutter, Jr., Associate Professor, Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames 50011; Paul S. Teng, Coordinator for IPM, International Rice Research Institute, P. O. Box 933, Manila, Philippines; and Fred M. Shokes, Associate Professor, North Florida Research and Education Center, Route 3, Box 4370, Quincy, FL 32351. Plant Dis. 75:1187-1188. Copyright 1991 American Phytopathological Society. DOI: 10.1094/PD-75-1187.