A confirmatory factor analysis of library use

For the past 25 years, public library administrators have pondered their institution's relationship to the computer. Since the 1980s, the integrated library system, which is based on a server-client model, has been a ubiquitous part of the library. These systems, however, are solely for use by the library staff. There have long been computers available for patrons but for many years these only provided access to the online catalog and databases on CD-ROM. Over time more applications were added to the patron computers including integrated office suites and web browsers. Public computers for patrons with access to the Internet and loaded with various productivity applications are now available in almost all public libraries across the country. At the same time that personal computers were proliferating, in both the private and public sphere more knowledge content became available digitally. Materials that were once available only in print, including books, periodicals, and databases, can now be accessed through the Internet. It is not surprising that it has been difficult for libraries to adapt to this change. An institution that was originally established to collect print materials now has to offer access to knowledge in many different formats. This study investigates one aspect of this change. The concept of "library use" has changed with the proliferation of digital media. Libraries of all types and the various administrative boards that control their funding allocated revenue budgets solely on circulation statistics. That is, the amount of money given to the library was based on how many books were checked out in a given year. This statistic does not adequately account for the actual services that libraries provide. In 2009, the editors of Library Journal [1] sponsored research for the development of a new scale measurement for rating library services based on four indicators. This study is a confirmatory factor analysis of this scale in order to validate this new measurement model. The initial data consisted of three hundred three (N =303) from the 2008 New Jersey Public Library Statistics [2]. 23 libraries did not respond to the survey, leaving a total of two hundred eighty libraries in the data set (n=280). These data are collected every year by the New Jersey State Library and are freely available on the institution's website (www.njstatelib.org). The New Jersey State Library collects these data via an electronic survey. An additional 38 libraries were removed because their scores fell more than three standard deviations beyond the mean on any one of the variables that were tested. Eight libraries were removed because they were multivariate outliers. This resulted in a sample size of two hundred thirty-four public libraries in New Jersey (n = 234). All questions on the survey (except for identification information) required whole number (ratio level) responses from the libraries. Items regarding revenue and expenses required whole dollar amounts. Computer Readable Materials Budget refers to the total amount spent on software, electronic books, and other items that must be used on a computer. Databases Owned indicates the total number of licensed databases for which the library pays. Libraries also indicated the number of computers available for public use. The survey also included two categorical questions. One asked whether or not the library made password free Wi-Fi available to the general public. The other asked whether or not the library made JerseyClicks, a full-text search portal funded by the state, available on their website. According to the new Library Journal Index mentioned above, four indicators are used to construct the library use score: library visits, circulation, program attendance, and public Internet computer use. Library visits refers to the total number of people who enter the library for any purpose. Circulation indicates the total number of "check-outs" for all materials including any renewals. It does not include virtual circulation or interlibrary loan. The total number of people at all programs either sponsored or hosted by the library is indicated by program attendance. Finally, public Internet computer use refers to the number of individuals who used public accessible computer terminals in a given year. These indicators were transformed into per-capita data by dividing each reported amount by the population of the library's municipality as indicated in the 2000 Census. Each number was then transformed into a z-score. A confirmatory factor analysis was conducted to assess the fit between the NJPL data and proposed factor structure for the Library Use Index proposed in Library Journal. The chi-square value for the overall model fit was not significant (χ² =.720, df = 2, p >.001) indicating that there is an adequate fit between the factor structure of the Library Use Index and the data. A "library use" score was then computed using the sum of the four standardized indicators. In accordance with the procedure given in Library Journal [3], since this preliminary score included scores with negative values (with a minimum value of -4.99), a correction factor of 5 was added to each score so that the variable Library Use Score would not include negative values. The Library Use Score for the libraries was M = 4.97, SD = 3.26 with a range of.007 to 15.981. The Library Use Score provides a single measure that can be used to compare individual public libraries with peer institutions.