Introduction - 2. Electronic Library Performance Indicators 3. Consolidated list of datasets - 4. Definitions of terms 5. They are not intended to replace these indicators and indeed it is strongly recommended that these indicators be collected together.
Great care is needed when using any performance indicator to make comparisons between libraries.
Indicators which are based on the target population are particularly problematic, because each library will define that population to reflect its own operational environment. Careful analysis of the definitions used to establish each dataset is therefore essential if valid comparisons are to be made. It is also recommended that sampling methods be agreed in advance between libraries where comparison is to take place. For example, academic libraries in a region or public libraries in a national context may agree to use the same methods and instruments. At this present point in time it is not possible to extract all of the datasets required for these performance indicators from all electronic library services.