Library Performance Index (ILP)

Multi-Factor Library Performance Evaluation


  • Markku Antero Laitinen National Library of Finland


Composite Index (IC), Library Performance Index (ILP), User Experience Index (IUX), Core Processes Index (ICP), Input Index (IIP), Use of Services Index (IUS), Decision-making Support


The Library Performance Index (ILP) is a composite index combining several indicators (sub-indices) derived from complementary views on library services and processes. At the ILP level, the composite index approach enables us to evaluate a complex phenomenon by grouping relevant factors, computing sub-indices of the groups, and computing a weighted sum of those with coefficients assigned by experts. We also apply the composite index approach at the group level, combining the values of the factors within a given group. Such factors can be statistics (e.g., the number of loans), opinions of library professionals (e.g., weighting the attributes of the sub-indices) and opinions of library customers (e.g., results from user surveys). By capturing multiple ‘dimensions’ of library performance, the ILP can be a valuable and effective tool. We illustrate the approach by dividing a number of library performance-related factors into four groups and computing their respective sub-indices: User Experience Index (IUX), Core Processes Index (ICP), Input Index (IIP), Use of Services Index (IUS). Each sub-index was discussed and defined in a dedicated workshop with library directors, developers, and finally the sub-indices were combined to the ILP. While opinions may vary on the contribution of specific factors to the overall library performance evaluation, our primary goal was to demonstrate the flexibility of the composite index-based approach.