This report provides the statistical tools necessary to measure the extent of error that exists in organizational record data and group survey data. It is felt that traditional methods of measuring error are inappropriate or incomplete when applied to organizational groups, especially in studies of organizational change when the same variables are measured at more than one point in time. Ways to identify true organizational change, separated from changes in measurement error, are described. Suggestions for research design discuss the appropriate level of the hierarchy studied and sample size. Reliability formulas, tests of significance, unbalanced designs, synchronization measures, and computational requirements are also discussed. (Author/GDC)