About the LJ Index of Public Library Service
Ray Lyons & Keith Curry Lance -- Library Journal, 2/15/2009
In June, LJ announced the development of a new assessment tool for public libraries—the LJ Index of public library service output.
The New LJ Index" (LJ 6/15/08, p. 38–41) described the analysis informing its design. Here, we announce the results of the first LJ Index of Public Library Service, sponsored by Baker & Taylor's Bibliostat. It is based on 2006 data reported by local libraries to their state library agencies and compiled by the Institute of Museum and Library Services (IMLS). We also identify factors that affect a library's Index score, discuss further the Index's design, and recommend how it can be used productively by all libraries. The top libraries are organized into star tiers, much like the Michelin guide, for example, with five, four, or three stars. Those without star ratings will be ranked in the online version of this article (available at www.libraryjournal.com/ljindex2009), and all included libraries will be available in a dynamic database format via Baker & Taylor's Bibliostat Connect.Star-rated public libraries
As readers peruse the accompanying tables, they should be aware of the following characteristics of the LJ Index of Public Library Service:
- This is an index of public library service output only and as such is determined equally by four related per capita output indicators: visits, circulation, program attendance, and public Internet computer use.
- Libraries are scored in relation to other peer libraries based on total operating expenditures rather than on community population.
- Scores are calculated using statistical methods that make year-to-year comparisons more accurate than other ranking approaches.
- A library's standing on this index will be meaningful if its leaders thoughtfully examine the four service indicators and note its standing on each among peer libraries.
Because data is not reduced to ranks, a very high value on one indicator relative to the group average can earn a library a higher score than another that bests it on the other three indicators. This sensitivity will make the LJ Index a valuable tool for identifying exemplary performance as well as dubious data.
Because the number of star-rated libraries is large (256), we have focused on a few libraries—ones representing different star ratings, expenditures groups, and regions—to use as examples as we discuss factors influencing a library's service output: its community, its organization and funding, and its leadership and management.
An output-based index
Traditionally, many public library decision-makers have focused on circulation alone as the performance indicator. Today, the full range of services includes electronic access, facilities use, and programming. So there is no compelling reason to give greater weight to one type of library use over another. Besides, weighting is an arbitrary process that it is best to avoid.
In the accompanying tables, the four per capita outputs are listed alongside the LJ Index scores to show why one library has a higher score than another. A library will score higher to the extent that it performs better on all four statistics. Frequently, higher scores go to those with the most visits or highest circulation—usually double-digit figures. Sometimes, higher scores are based on better program attendance or more public Internet computer uses—usually in the single digits (or less). Program attendance tends to produce smaller numbers than visits because a library event is only one reason to visit and programs provide in-depth experiences. Furthermore, Internet usage numbers are smaller than circulation because they count computer uses, not the number of resources accessed. Given these contexts, one would not expect figures on the same scale, nor could one safely conclude from the varying ranges that one type of use is more important than another.
The peer groups
The LJ Index of Public Library Service groups public libraries by total operating expenditures rather than population of legal service area. [See table below.]
For libraries spending less than $5 million annually, the groups are designed to be similar in size (each with about 1100 to 1200 libraries). The smaller number of libraries spending more than $5 million warrants creating the three smaller groups of libraries with the highest annual spending.
What the scores represent
LJ Index of Public Library Service scores are based on a library's standing on the four per capita outputs relative to the averages for its peer group. Scores are determined by combining the four indicators in a statistically appropriate manner that avoids disadvantages of using ranks or percentiles. Exaggerated higher scores are useful “red flags.” They may indicate either exceptional performance or a need to review local data collection procedures. Why these particular measures matter is detailed in “The New LJ Index.” As a measure of library output, the LJ Index does not purport to assess library quality, excellence, or value.
Ratings vs. rankings
“The New LJ Index” proposed a new “ranking” system. However, since then, we have decided to make the LJ Index of Public Library Service a library “rating” system. Because per capita differences among libraries are often miniscule (a few 1/10ths of a point), it is inappropriate to attach excessive importance to a precise score. This is why the LJ Index uses a star-rating system to identify three groups of deserving libraries in each expenditures peer group. Five-star libraries claim the top ten places, while four-star libraries are the next ten, and three-star libraries are the next ten. The exception is the top group—libraries spending $30 million or more (31 libraries). Each of its star categories consists of only five libraries. Also, in the $5 million–$9.99 million category, there are 11 three-star libraries, owing to a tie.
And, remember, the star-rating group in which your library may appear—and whether or not it continues to appear—will be influenced by self-exclusion from these ratings by libraries that do not report data. In other words: you have to be in it to win.
Next: Lessons from the Index
| TOTAL OPERATING EXPENDITURES | NUMBER OF LIBRARIES |
| $30.0M or more | 31 |
| $10.0M–$29.9M | 88 |
| $5.0M–$9.9M | 159 |
| $1.0M–$4.9M | 1,125 |
| $400K–$999K | 1,247 |
| $200K–$399K | 1,089 |
| $100K–$199K | 1,173 |
| $50K–$99K | 1,115 |
| $10K–$49K | 1,088 |
| TOTAL IN LJ INDEX | 7,115 |
| KEY: M–Millions K–Thousands | |
Ray Lyons is an independent consultant and statistical programmer in Cleveland. He recently received his MLIS and has an MPA (public administration) with a specialty in quantitative methods. Keith Curry Lance is an independent consultant based in Denver. He was the longtime director of Colorado’s Library Research Service and a founding member of the Steering Committee of the Federal-State Cooperative System (FSCS) for Public Library Data.
