Appendix A: Technical Notes

Caution on the use of data by state, and by level and control of institution

This is a descriptive report that focuses on information from a census of academic libraries in 2008. The presentation of numbers, proportions, and percentages is descriptive only of libraries in the period referenced. While data were imputed for nonresponse, the number of unit nonresponses can vary by state and affect the reliability of the state data. See Methodological table A-1 for item response rates by level and control of institution. Methodological table A-2 presents the distribution of the set of unit nonrespondents by state and by level and control of institution. The data user should be especially cautious in using data at a level of detail where the nonresponse rate was 15 percent or greater. Methodological table A-3 gives the number of academic libraries by state, level, and control of institution.