This technical report provides an updated assessment of the problem of optimizing the periodicity of the Schools and Staffing Survey (SASS). Making use of data from three rounds of SASS data collection (for school years 1987-88, 1990-91, and 1993-94), the report extends and updates the preliminary findings and interim assessments that were previously published in a paper for the American Statistical Association (D. Ghosh et al., 1994) and a technical report for the National Center for Education Statistics (NCES) (D. Ghosh et al., 1995). Part I of the report (Sections 1 through 6) presents the analysis and findings, while Part II provides documentation and numerical results in terms of error projections for selected models, policy variables, cost rations, and periodicities. Basic results are provided for four probable error models. Section 1 provides an overview of the report and characterizes the general task of optimizing the periodicity of the SASS as one of identifying decision rules that will result in the selection of intersurvey time intervals and survey sample sizes that are in some sense "jointly optimal subject to a known, fixed set of cost constraints." While the first three rounds of the SASS were conducted at 3-year intervals, budget constraints meant that the next round was delayed to 5 years later. Section 2 covers the main modeling and analysis features of this study, while section 3 provides a brief review of time series methodology in relation to the periodicity problem. Section 4 sets forth summary conclusions and recommendations, concluding with the suggestion that the NCES should consider adopting an alternating large and small sample design for the SASS with an appropriate full-sample periodicity (such as 6 years) together with a mid-period fractional-sample data collection at the halfway time between full sample data collections. Section 6 provides an extensive bibliography for the whole report. Part II has four sets of detailed appendix tables. Appendix A provides large-sample scenarios for public schools and four states; Appendix B provides an alternating large and small sample design. Appendix C provides similar scenarios for private schools, and Appendix D provides an alternating large and small sample design for private schools. (Contains 2 figures, 8 tables, and 54 references.) (SLD)