The Purpose of Collection Assessment

In the past, libraries were judged on the quality of their collection.  It was generally assumed that libraries with larger collections were stronger libraries.  Thus, some accrediting associations evaluated school libraries by looking at the number of books that they contained with little concern about whether those books were being used by the students.

This way of evaluating libraries is changing.  Increasingly, libraries are evaluated by their access to accurate and reliable information rather than the number of books that they own.  This change has come about for two reasons.  

First, it has been recognized that we live in a rapidly changing society.  Information contained in a book published five or ten years ago may no longer be accurate. 

There is a famous library story about this.  It seems that a school student in the early 1990's wrote a report that included the statement that "someday, humans may walk on the moon."  The teacher was going to give the student a poor grade until it was discovered that the only books on space travel in the school library had been written in the early 1960's.

A second reason that libraries are now evaluated by the accuracy and reliability of their information is because information is now available in many different sources.  People now expect to be able to find information on video, on CD-ROM's and on-line.  The same student who was excused for her mistake about the moon landing in the 1990's might not be excused today, because she would be expected to check the Internet and other sources to get more up-to-date information.

This does not mean, of course, that libraries must vouch for every piece of information in their collections.  But it does mean that library users will expect library collections to be more up-to-date and comprehensive than in the past.  A school or public library that has books from the 1960's on topics such as space travel will not be regarded as a good library.  (The only exception would be if these books were deliberately being kept for historical purposes.  However, this would not normally fall within the mission of a small school or public library.)

In order to meet the changing needs of their clients, librarians must constantly evaluate their collections.  When they find a weakness in a subject area of interest to their community, they must find a way to strengthen that part of their collection.  If they have a number of out-of-date materials about a subject, they must remove them and replace them with sources that are more up to date.

The process of continuously evaluating the library collection is called collection assessment. The purpose of collection assessment is to assure that the library's collection meets the current needs of the community by providing reliable, up-to-date, and attractive materials and other information sources.  In subject areas that are controversial, it also assures that a variety of opinions are represented.

The process provides information that can be used in making decisions regarding purchases and weeding.  It may help the library focus its resources on important subject areas that need to be built up.  It may tell the library what parts of the collection need particular attention for weeding.

One important side benefit of performing a continuous collection assessment is that it helps library staff members know the collection better.  By looking at the collection and evaluating it, staff members will learn more about the kinds of information that are and are not available in their library.