1. To determine the overall book availability rate for the University of Ilorin College of Health Sciences Library; and,
2. To find out the library's level of performance with regard to four parameters, namely acquisitions performance, circulation performancee, library operations performance and Library user performance measures.

Literature Review

The term "availability study" is often used interchangeably with such terms as satisfaction study, frustration study, failure study and shelf availability study. These terms, according to Nisonger (1992), are about whether or not a library user can find a book on the shelf when needed. They are also closely related to the concept of performance measurement, the purpose of which is to determine how well a library is faring.

Performance measurement dates back to the 1930s (Ciliberti, 1987)while the first available study dates back to 1934 (Mansbridge, 1986). Since the Mansbridge study, a number of approaches to availability studies have been developed, one of which is the Kantor (1976) branching technique, or Kantor model.

Kantor succinctly explained his branching technique in a 1976 article using the data collected at Case Western Reserve University in 1972 and 1976. He and Saracevic (1977) later wrote a paper devoted to the application of the technique to various published availability studies dating back to 1957. In concluding the articles, however, Kantor emphasized the need to use availability studies judiciously, saying that if library procedures are reducing the availability rate, "management analysis of policies rather than statistical analysis is required."

In their textbook, Baker and Lancaster (1991) succinctly describe Kantor's branching technique. This description is followed by sections devoted to the conduct of citation-based and patron-based availability studies. Next is the analysis of studies reported from 1976 to 1984, with the search failures in most cases being attributed to acquisition, circulation and library patron errors. The chapter concludes with a distinction between the two types of traditional availability studies, namely analysis by type of user and availability over time.

Using the Kantor model, Bachmann-Derthick and Spurlock (1989) investigated the availability of journals in the University of New Mexico Library in 1986. The study was based on patrons' actual searches for 483 journals with the results indicating: (1) an overall success rate of 56 percent; (2) 58.2 percent of the items sought were owned by the library; and, (3) a circulation performance of 96.7, which the researchers considered higher than the reported results in most previous book availability studies.

In another development, Broadbent (1984) conducted "a user and stock failure" survey at the State Library of Victoria in April and May 1983. The success rate for the 2,821 books sought by patrons was 80.9 percent while the stock failure rate stood at 13.6 percent. The latter consisted of books not owned by the library, books held in limited copies and misplaced books. Of the 721 subject searches recorded, 79.9 percent were successful. The majority of the subject search failures was due to cataloguing problems, followed by cases of insufficient library copies and irrelevant items.

In 1984, Ferl and Robinson (1986) carried out a book availability study at the University Library, University of California, Santa Cruz in November 1984 using the researcher-designed forms for data collection and Kantor's branching technique for analysis. Of the 480 items sought by patrons, 61.3 percent were found while 38.7 percent could not be located. The reasons for the 23 search failures are given in one of the tables in the article reporting the study.

Following the installation of an automated system at the University Library, University of California, Santa Cruz, Frohmberg, et al. (1980) carried out six availability studies over a two-year period (1978-1979 and 1979-1980), the purposes of which were to assess the impact of automation on the availability of materials in the library. Each of the studies was two-fold: an objective availability study based on actual users' searches for the library's materials, and a perceived availability study based on the users' responses to a questionnaire about their views on the availability of materials in the library. The results of the studies showed that the automated system had increased the availability of materials in the library generally. There were, however, striking differences in the results of the objective availability analysis and those of the perceived availability analysis, leading to the conclusion that it is easier to change performance than patrons' attitudes.

More importantly, Wulff (1978), using the Kantor model, conducted an analysis of the availability of the book collection in the University of Minnesota Bio-Medical Library. Of the 388 books sought by patrons during the study, 245 (63 percent) were found while 143 (37 percent) were not found. There were four categories of reasons for the search failures recorded in the study, each of which represented a performance measure that could account for a search failure. The calculated values of the four performance measures for the library were; acquisition performance, 94 percent; circulation performance, 90 percent; library operations performance, 86 percent; and, library user performance, 88 percent, "By carrying out an availability study from time to time," he concluded, "a library can with an improved objectivity evaluate that portion of its services that is reflected in the immediate availability of its book collection."

The present study was an attempt made by the writers to evaluate the Nigerian College of Health Sciences Library in terms of the availability of its book collection using the Kantor model.

Methodology

Data for the study were collected from a total of 400 users of the University of Ilorin College of Health Science Library in May, 2007. The data were gathered and analyzed largely using the Kantor method.

Over four weeks in May 2007, copies of the two-part researcher-designed questionnaire were distributed to the clientele of the library who were using the card catalogue and/or browsing through the book stacks. The first part of the questionnaire was meant for the participating library users and it was designed to elicit the following from each respondent:

• User's library registration number, age group, gender, status, specialty if a staff member and major course of study if a student.
• The author(s), title(s) and call numbers of the book(s) sought and whether or not the book(s) was/were found.

Each respondent was requested to leave the completed questionnaire with the library staff on leaving the library. In all, 420 questionnaires were distributed; out of these 400 were duly completed and returned for analysis. The 400 questionnaires yielded a total 2,221 sought titles with 1,345 titles found and 876 titles not found.

As the questionnaires were returned, two research assistants checked the reportedly ‘not found’ books against the library's shelves and records and then noted in the appropriate column in part two of the questionnaire the reason(s) for not finding the books.

From the data gathered on the books searched, the overall book availability rate for the library was computed using the following formula (Morgan, 1995):

Number of successful searches/Total number of searches

Then, following the Kantor model, the reasons for not finding the books searched were divided into four categories, each of which represented a performance measure. From these data, a branching diagram was constructed from which the values of the four performance measures for the library, represented by the symbols PU, PL, PC and PA, were calculated using the formulas (Wulff, 1978):

PU = S/T, where T=S+DU
PL = T/U, where U=T+DL
PC = U/V, where V=U+DC

PA = V/W, where W equals the total number of books searched and PU, PL, PC, and PA each represents the performance level derived for each performance measure using the branching diagram.

Methodology

Profile of Respondents

The respondents' demographics are presented in Tables 1 and 2. From Table 1, it is clear that the undergraduates were the largest users of the library's book collection with the MBBS and B.Sc. (Anatomy) students dominating. In contrast, few graduates and staff used the collection. For obvious reasons, these situations were not surprising. First, the undergraduates constituted the bulk of the population served by the library and, by extension, the largest group of registered readers. More importantly, the undergraduates' book needs might be greater than those of the graduates and staff who might understandably be more interested in periodicals an//or technical reports than books.

In terms of gender (Table 2), more male students used the library book collection than females; possibly due to the fact that the library's registered users were predominantly males.

Table 1: Distribution of respondents by status, programmes, and departments.

Table 1: Distribution of respondents by status, programmes, and departments.
Status	Number of respondents	Percentage of respondents
Undergraduate (348)
MBBS	128	36.80
B.Sc (Anatomy)	125	35.92
B.Sc (Physiology)	95	27.30
Postgraduate (12)
M.Sc (Anatomy)	2	16.67
M.Sc (Physiology)	2	16.67
Master of Public Health (MPH)	5	41.67
Master of Community Health (M.Com.H)	3	25.00
Staff (40)
Anatomy	16	40.00
Behavioral Sciences	8	20.00
Pathology	4	10.00
Surgery	12	30.00

Table 2: Distribution of respondents by gender.

Table 2: Distribution of respondents by gender.
Gender	Number of respondents	Percentage of respondents
Male	226	56.50
Female	174	43.50
Total	400	100.00

Book Availability Rate

Of the 2,221 titles searched, 1,345 were found while 876 were not found, giving an overall book availability rate of 60.5 percent for the library. Unfortunately, no currently published Nigerian or other data was available for comparison. The rate is, however, close to the 63 percent reported by Wulff (1978) in the University of Minnesota Bio-Medical Library study, though that study was conducted some 30 years ago.

In Table 3 and Figure 1 are data from which the four performance levels for the library (Table 4) were computed:

As observed by Wulff (1978), such figures as the foregoing can be interpreted from the point of view of the library concerned as well as its users. From the point of view of the University of Ilorin College of Health Sciences Library it can be said that there is no cause for concern with a selection and acquisition programme that can produce 87 percent of the books needed by its users as shown in Table 4.

Conversely, the results of analysis of the search failures by the performance measures vis-á-vis the total numbers of books searched in each case(Figure 1) were quite striking. They suggest that:

• Thirteen percent (288 ÷ 2221 × 100) of the books needed by such users were not owned by the library;
• Ten percent (224 ÷ 2221 × 100) of the books needed had been checked out;
• Ten percent (218 ÷ 2221 × 100) of the books needed were in the library but not on the shelves where they were expected to be found; and,
• Seven percent (146 ÷ 2221 × 100) of the books needed were in the right places on the shelves but were not found due to the readers' mistakes.

The overall implication of the above results is that users left the library without two of every five books needed (876 ÷ 2221 × 100 ? 40 percent = 2/5) which is not good enough for a developing country like Nigeria where most university library users, particularly undergraduates, depend on their institutions' libraries for most of their book needs.

Performance Levels

In Table 3 and Figure 1 are data from which the four performance levels for the library (Table 4) were computed:

Table 3: Books not found by the users of the University of Ilorin College of Health Sciences Library.

Table 3: Books not found by the users of the University of Ilorin College of Health Sciences Library.
Reason for not finding book	Number of books	Percentage of books
Acquisition performance (288)
Book not owned	288	32.88
Circulation performance (224)
Book in use in library	92	10.50
Book on loan	132	15.07
Library operations performance (218)
Book mis–shelved	46	5.25
Book on return shelf	70	8.00
Book in place not indicated in catalogue	56	6.39
Book missing	46	5.25
Library user performance (146)
Book searched using wrong call mark	46	5.25
Book in place indicated in catalogue	46	5.25
Book properly shelved	54	6.16
Total Books not found	876	100.00

Figure 1

Table 4: Performance levels for the University of Ilorin College of Health Sciences Library.

Table 4: Performance levels for the University of Ilorin College of Health Sciences Library.
Performance measure	Value (percent)
Acquisition performance (PA)	87
Circulation performance (PC)	88
Library operations performance (PL)	87
User performance (PU)	90

Conclusion

This study was an attempt made by the authors in May 2007 to determine the book availability rate and performance levels for the University of Ilorin College of Heath Sciences Library, Nigeria.

The book availability rate of 60.5 percent obtained for the library gives no cause for concern, though no currently published Nigerian or other data were available for comparison.

In contrast, the fact that users might be leaving the library without two of every five books needed calls for a review of the various aspects of the four performance measures investigated that might account for this situation. This review is being done with greater attention paid to the measures over which the library has control. These include measures relating to library operations, circulation procedures and user lapses.

References

Bachmann-Derthick, Jan, and Sandra Spurlock. "Journal Availability at the University of New Mexico." Advances in Serials Management 3 (1989): 17-212.

Baker, Sharon L. and F "Evaluation of Materials Availability." In their Measurement and Evaluation of Library Services, pp.143-80. Arlington, Va.058; Information Resources Press, 1991.

Broadbent, Marianne. "Who Wins? Who Loses? User Success and Failure in the State Library of Victoria ." Australian Academic & Research Libraries 15 (1984): 65-80.

Ciliberti, Anne C. "Material Availability: A Study of Academic Library Performance." College & Research Libraries 48 (1987): 513-27.

Ferl, Terry Ellen and Margaret G. Robinson. "Book Availability at the University of California, Santa Cruz." College & Research Libraries 45 (1986): 501-8.

Frohmberg, Katherine A., Paul Kantor and William Moffett. (1980) "Increases in Book Availability in a Large Library." In Communicating Information: Proceedings of the 43rd ASIS Annual Meeting: Anaheim, California, October 5-10, 1980, Allan R. Benefeld and Edward John Kazlaukas, eds., p.282-84. White Plains, N.Y.: Knowledge Industry Publications, 1980.

Kantor, Paul B. "Availability Analysis." Journal of the American Society for Information Science 27 (1976): 311-19.

Mansbridge, J. "Availability Studies in Libraries." Library & Information Science Research 8, no.4 (1986): 299-314.

Morgan, Steve. Performance Assessment in Academic Libraries. London: Mansell Publishing, 1995: 77.

Nisonger, Thomas E. Collection Evaluation in Academic Libraries: a Literature Guide and Annotated Bibliography. Englewood, Colo.: Libraries Unlimited, 1992: 61.

Saracevic, T., W.M. Shaw, and P.B. Kantor. "Causes and Dynamics of User Frustration in an Academic Library." College and Research Libraries 3, no.1 (1977): 7-18.

Wulff, Yvonne. "Book Availability in the University of Minnesota Bio-Medical Library." Bulletin of the Medical Library Association 66, no.3 (1978): 349-50.

Acknowledgements

The authors are grateful to Professor B.L. Adeleke, Department of Statistics, University of Ilorin, Ilorin, Nigeria for his computational assistance and useful comments on the draft of this article. They also appreciate the assistance of Messrs. M.A. Sulaiman and D.T. Razaq, University of Ilorin College of Health Sciences Library, for the collection of data for the study.

About the authors

I.A. Alao is Acting College Librarian in the College of Health Sciences at the University of Ilorin in Nigeria. A.L. Folorunso and H.T. Saka are Cataloguers in the University of Ilorin Library.

© 2009 I.A. Alao, A.L. Folorunso and H.T. Saka.