Methodology for Studying Use of and Reactions to Various Book Formats

The project's Analytical Principles and Design document lays out the evaluation methodology.^[5] Formulated in the first year of the project, this methodology re-

mains the working plan. Here are some of the key measures for documenting use of the on-line books:

• The records of the Columbia computing system provide, for the most part, the use data for the on-line books. For books accessed via the World Wide Web, information on date, time, and duration of session involving an on-line book, user's cohort, location of computer, number of requests, amount of the book requested, and means of accessing the book will be available. These data became available in summer 1997 with the full implementation of the authentication system and related databases.

• Circulation data for each print book in the regular collection provides information on number of times a book circulates, circulation by cohort, duration of circulation, number of holds, and recalls. For most libraries, the data available for reserve books is the same as that for books in the regular collection as the CLIO circulation system is used for both.

• The records of the Columbia computing system provide, for the most part, the use data for the books accessed via CNet, Columbia's original, gopherbased Campus Wide Information System, including the number of sessions and their date and time. These records do not include the duration of the session, the activity during the session, e.g., printing or saving, or anything about the user. Thus, all we can analyze are the patterns of use by time of day, day of week, and over time.

• Until March 15, 1997, for books accessed via CWeb, we knew the use immediately preceding the hit on the book and the day and time of the hit. For data collected through that point, our analysis is constrained to patterns of use by time of day, day of the week, and over time. By manual examination of server data, we counted how many hits a user made on our collection during one session and the nature of those hits.

• Since March 15, 1997, we are able to link user and usage information and conduct a series of analyses involving titles used, number of hits, number of books used, and so on by individual and to group those individuals by department, position, and age. These data do not yet include sessions of use, just the magnitude of overall use during the period. Session-specific data are available starting in fall 1997.

We are using a wide range of tools in trying to understand the factors that influence use of on-line books. Table 17.1 summarizes our complex array of surveys and interviews.