With Ray Lyons, Keith proposed the LJ Index in a 2008 article solicited and published by Library Journal. 

Ray and Keith collaborated on this project through the ninth edition in 2016.  Ray passed away unexpectedly and far too soon on May 14, 2017.  From the tenth edition in 2017, Keith pursued the project on a solo basis.

To receive an LJ Index score, a public library had to meet four criteria:

• Meet the IMLS definition of a public library
• Have a legal service area population of at least 1,000
• Have annual operating expenditures of at least $10,000
• Report all seven per-capita statistics on which the score is based: visits, total circulation, circulation of electronic materials (added in the 2016 edition), successful retrievals of electronic information (added in the 2020 edition), public Internet computer use, Wifi sessions (added in the 2019 edition), and program attendance.

As of 2020, there were also outlier criteria that exclude libraries from consideration as Star Libraries if one of those statistics was more than 3 standard deviations from its spending peer average and the associated standard score accounted for half or more of the raw index score.

Libraries were scored in nine categories of annual operating expenditures, based on their relationship to their category’s average on each statistic.

Between 2009 and 2022, there were 15 editions of America’s Star Libraries, the annual announcement of LJ Index results and the Star Library ratings based on them.  The last five editions from 2018 to 2022 forward remain available on the LJ website.