Inventory (library)
Encyclopedia
Libraries
need methods, such as inventories, to determine whether or not their collections are in good shape, or whether or not some preservation
or conservation activities are necessary. How do libraries identify which particular items sitting on their shelves that may not have crossed the circulation desk
in a number of years need special attention?
may have millions of books; therein lies our problem. Doing an annual (or less frequent) physical inventory with the laying on of hands on each individual item may not be financially feasible, employees required may not have extra time to devote to such an inventory, and there are no financial rewards for the Library for completing an inventory—essentially we are out looking for our problem books and missing items when we conduct an inventory. The solutions to solving the problems that are discovered (books in need of repurchase, rebinding, repair, or digitization) are expensive and labor intensive. Inventories may not take place for decades, if ever, at large academic institutions because of these restraints.
Although collecting new materials is viewed as a central mission of the library, maintaining the condition of library collections, which includes less satisfactory activities such as weeding, book repair, shifting and counting what libraries think they have on their shelves, are also a vital part of the library’s mission to provide access to current patrons, as well as those people who will use the library at some point in the future. Adelphi University
Libraries in 2004 completed a complete physical inventory of its collections (465,629 volumes) as part of its strategic planning process utilizing the Association of College and Research Libraries Standards for Libraries in Higher Education. Examining item by item with a barcode scanner and a laptop, the objective is to adjust bibliographic and item records in theirs and OCLC
’s WorldCat
databases.
Complete inventory or stocktaking is often a regular part of the school library media specialist
’s job at K-12 institutions, where inventory may be a legal requirement that shows that the libraries are accountable for the money they have spent throughout the year. Checking for lost books and materials can be similarly compared to audit
ing. We are trying to guarantee that our collections as listed in our OPACs and Finding Aids do not lack integrity. School libraries use the inventory to assess the collection (numbers, age and ratio:student) against benchmarks of accrediting institutions, and also to examine each resource and determine its future in the collection based on age, relevance, currency and condition—which may include repair, replacement, disposal or cleaning to ensure that attractive, up-to-date resources are available for patrons. Inventory can also identify anomalies in the catalog and provide an opportunity to correct catalog records and labeling of items. This is also a time when shelves can be rearranged to minimize overcrowding to prevent damage.
Sampling
is a compromise measure, which can be an important management tool. Random sampling of library collections can give a quick and clear assessment measure of a collection—whether or not the books are present, and whether or not those books present are in good physical condition. In 1982, the California State University libraries, suggested inventory procedures to insure that the 19 campus collections were secure and intact. They recognized that a complete regular inventory was too expensive, and decided that the best method of assessing book loss would be to use sampling. Every three years, a sample was to be taken of an identified number of items in each Library of Congress letter classification
. If loss rates were more than 1% for two years in a row, this would indicate that a full inventory was needed.
“A random sampling of the collection serves as an indicator for the rest of the collection. If all the items are accounted for in a random sampling, then it can be assumed that rest of the collections’ records is just as reliable. However, a complete inventory provides the institution with the knowledge that the entire collection can be accounted for; the random sampling is used to check the consistency of the collections’ records.”
Next, the Library needs to decide upon the size of its sample. More datapoints, of course result in more accurate data about the collection. There are two types of errors possible in sampling: tolerance and confidence. Tolerance is the unexact percentage, a maximum deviation from the nominal error value, for example, a survey question may be accurate for 85-95% of the population, it could also be stated 90% ±5; in this case, the tolerance is five. Confidence is the second error, measuring the certainty of a true answer within the limits stated in the tolerance. If there is a 90 per cent confidence, it is predicted that if the sample study is repeated ten times using different samples, but with the same tolerance, then the results would be accurate for nine of those studies out of ten.
In the table below, for a tolerance of ±5%, the sample sizes for a collection of more than 50,000 books would be 381 items for 95% confidence, and 648 items for 99% confidence. To achieve a lower tolerance of ±1% one would have to sample thousands of books, which might stretch the resources available for even a sample inventory. Surveying 270 to 655 volumes is much more reasonable for the average-sized library staff.
An alternative for counting hundreds of books in a given random sample is to count until you know that you do or do not have a problem. The Prescott Memorial Library at Louisiana Tech employed sequential analysis
in the late 1980’s when working on automation of the collections.
Random selection of the books can take place in a couple of different ways. If in addition to the physical condition of items, a library also wants to know whether or not items are missing from shelves, random samples should be generated from the library’s integrated library system
(ILS). If librarians are just accessing the collection for preservation purposes, they can easily count ranges, columns, shelves and books and use Microsoft Excel
or other spreadsheet software to create random sample
s. It should be noted, however, that misplacement of books on shelves does have associated costs—in the patron’s satisfaction with the library’s services and in staff time trying to locate missing books. It may be well worth the extra time to figure out how to extract random items from your library’s ILS to complete your sample.
Costs for sampling 384 random items at the University of Illinois at Urbana-Champaign in 1987 were less than $5000. The UIUC Library employed eleven graduate students from the school of library and information science, who received training and supervision. Each surveyor collected forty samples, 90% of the surveys were completed on the first day in 5.5 survey hours.
Using the results of the library’s collection assessment, budgetary requests can be substantiated by data. The library needs an increase in budget to care for aging collections, or the library needs an increase in funding to add new materials for our students to meet deficiencies and weaknesses. This strategy was employed by the Joyner Library at East Carolina University
after an inventory and shelf-analysis project in 2005.
ADDITIONAL REFERENCES
Baird, Brian. Library Collection Assessment through Statistical Sampling, The Scarecrow Press, Lanham, MD, 2004.
Ernick, Linda. “Floating Bibs and Orphan Bar Codes: benefits of an inventory at a small college.” Library Resources & Technical Services, 49(3), 2005, pp. 210-216.
Henige, David. “Epistemological Dead End and Ergonomic Disaster? The North American Collections Inventory Project.” The Journal of Academic Librarianship, 13(4),1987, pp. 209-213.
Shouse, Daniel L. and Linda Teel. “Inventory: catalyst for collection development.” Collection Building, 25(4), 2006, pp. 129-133.
Wild, Judith W. “Inventory at Brooklyn College, 1998-1999.” Library Resourcs & Technical Services, 46(2), 2002, pp. 62-71.
Library
In a traditional sense, a library is a large collection of books, and can refer to the place in which the collection is housed. Today, the term can refer to any collection, including digital sources, resources, and services...
need methods, such as inventories, to determine whether or not their collections are in good shape, or whether or not some preservation
Preservation (library and archival science)
Preservation is a branch of library and information science concerned with maintaining or restoring access to artifacts, documents and records through the study, diagnosis, treatment and prevention of decay and damage....
or conservation activities are necessary. How do libraries identify which particular items sitting on their shelves that may not have crossed the circulation desk
Library circulation
Library circulation or library lending comprises the activities around the lending of library books and other material to users of a lending library. A circulation or lending department is one of the key departments of a library....
in a number of years need special attention?
Role of Inventory in the Mission of Libraries
Libraries have thousands of books; large academic librariesAcademic library
An academic library is a library that is attached to academic institutions above the secondary level, serving the teaching and research needs of students and staff...
may have millions of books; therein lies our problem. Doing an annual (or less frequent) physical inventory with the laying on of hands on each individual item may not be financially feasible, employees required may not have extra time to devote to such an inventory, and there are no financial rewards for the Library for completing an inventory—essentially we are out looking for our problem books and missing items when we conduct an inventory. The solutions to solving the problems that are discovered (books in need of repurchase, rebinding, repair, or digitization) are expensive and labor intensive. Inventories may not take place for decades, if ever, at large academic institutions because of these restraints.
Although collecting new materials is viewed as a central mission of the library, maintaining the condition of library collections, which includes less satisfactory activities such as weeding, book repair, shifting and counting what libraries think they have on their shelves, are also a vital part of the library’s mission to provide access to current patrons, as well as those people who will use the library at some point in the future. Adelphi University
Adelphi University
Adelphi University is a private, nonsectarian university located in Garden City, in Nassau County, New York, United States. It is the oldest institution of higher education on Long Island. For the sixth year, Adelphi University has been named a “Best Buy” in higher education by the Fiske Guide to...
Libraries in 2004 completed a complete physical inventory of its collections (465,629 volumes) as part of its strategic planning process utilizing the Association of College and Research Libraries Standards for Libraries in Higher Education. Examining item by item with a barcode scanner and a laptop, the objective is to adjust bibliographic and item records in theirs and OCLC
OCLC
OCLC Online Computer Library Center, Inc. is "a nonprofit, membership, computer library service and research organization dedicated to the public purposes of furthering access to the world’s information and reducing information costs"...
’s WorldCat
WorldCat
WorldCat is a union catalog which itemizes the collections of 72,000 libraries in 170 countries and territories which participate in the Online Computer Library Center global cooperative...
databases.
Complete inventory or stocktaking is often a regular part of the school library media specialist
Teacher-librarian
A teacher-librarian , school librarian, or school library media specialist , is a certified teacher who also has training in librarianship...
’s job at K-12 institutions, where inventory may be a legal requirement that shows that the libraries are accountable for the money they have spent throughout the year. Checking for lost books and materials can be similarly compared to audit
Audit
The general definition of an audit is an evaluation of a person, organization, system, process, enterprise, project or product. The term most commonly refers to audits in accounting, but similar concepts also exist in project management, quality management, and energy conservation.- Accounting...
ing. We are trying to guarantee that our collections as listed in our OPACs and Finding Aids do not lack integrity. School libraries use the inventory to assess the collection (numbers, age and ratio:student) against benchmarks of accrediting institutions, and also to examine each resource and determine its future in the collection based on age, relevance, currency and condition—which may include repair, replacement, disposal or cleaning to ensure that attractive, up-to-date resources are available for patrons. Inventory can also identify anomalies in the catalog and provide an opportunity to correct catalog records and labeling of items. This is also a time when shelves can be rearranged to minimize overcrowding to prevent damage.
Sampling
"You don't have to eat the whole ox to know that it is tough." - Samuel JohnsonSampling
Sampling (statistics)
In statistics and survey methodology, sampling is concerned with the selection of a subset of individuals from within a population to estimate characteristics of the whole population....
is a compromise measure, which can be an important management tool. Random sampling of library collections can give a quick and clear assessment measure of a collection—whether or not the books are present, and whether or not those books present are in good physical condition. In 1982, the California State University libraries, suggested inventory procedures to insure that the 19 campus collections were secure and intact. They recognized that a complete regular inventory was too expensive, and decided that the best method of assessing book loss would be to use sampling. Every three years, a sample was to be taken of an identified number of items in each Library of Congress letter classification
Library of Congress Classification
The Library of Congress Classification is a system of library classification developed by the Library of Congress. It is used by most research and academic libraries in the U.S. and several other countries; for example, Australia and Taiwan, R.O.C. It is not to be confused with the Library of...
. If loss rates were more than 1% for two years in a row, this would indicate that a full inventory was needed.
“A random sampling of the collection serves as an indicator for the rest of the collection. If all the items are accounted for in a random sampling, then it can be assumed that rest of the collections’ records is just as reliable. However, a complete inventory provides the institution with the knowledge that the entire collection can be accounted for; the random sampling is used to check the consistency of the collections’ records.”
Determining the Sample Size and Items
First, it must be determined if the entire collection, including stacks, reference and special collections will be sampled together or if just a particular area will be analyzed. At the University of Illinois, their bookstacks included government publications and the Asian library, but these special holdings were not included in their study. Unbound items may also be excluded.Next, the Library needs to decide upon the size of its sample. More datapoints, of course result in more accurate data about the collection. There are two types of errors possible in sampling: tolerance and confidence. Tolerance is the unexact percentage, a maximum deviation from the nominal error value, for example, a survey question may be accurate for 85-95% of the population, it could also be stated 90% ±5; in this case, the tolerance is five. Confidence is the second error, measuring the certainty of a true answer within the limits stated in the tolerance. If there is a 90 per cent confidence, it is predicted that if the sample study is repeated ten times using different samples, but with the same tolerance, then the results would be accurate for nine of those studies out of ten.
In the table below, for a tolerance of ±5%, the sample sizes for a collection of more than 50,000 books would be 381 items for 95% confidence, and 648 items for 99% confidence. To achieve a lower tolerance of ±1% one would have to sample thousands of books, which might stretch the resources available for even a sample inventory. Surveying 270 to 655 volumes is much more reasonable for the average-sized library staff.
An alternative for counting hundreds of books in a given random sample is to count until you know that you do or do not have a problem. The Prescott Memorial Library at Louisiana Tech employed sequential analysis
Sequential analysis
In statistics, sequential analysis or sequential hypothesis testing is statistical analysis where the sample size is not fixed in advance. Instead data are evaluated as they are collected, and further sampling is stopped in accordance with a pre-defined stopping rule as soon as significant results...
in the late 1980’s when working on automation of the collections.
Random selection of the books can take place in a couple of different ways. If in addition to the physical condition of items, a library also wants to know whether or not items are missing from shelves, random samples should be generated from the library’s integrated library system
Integrated library system
An integrated library system , also known as a library management system ,is an enterprise resource planning system for a library, used to track items owned, orders made, bills paid, and patrons who have borrowed....
(ILS). If librarians are just accessing the collection for preservation purposes, they can easily count ranges, columns, shelves and books and use Microsoft Excel
Microsoft Excel
Microsoft Excel is a proprietary commercial spreadsheet application written and distributed by Microsoft for Microsoft Windows and Mac OS X. It features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications...
or other spreadsheet software to create random sample
Random sample
In statistics, a sample is a subject chosen from a population for investigation; a random sample is one chosen by a method involving an unpredictable component...
s. It should be noted, however, that misplacement of books on shelves does have associated costs—in the patron’s satisfaction with the library’s services and in staff time trying to locate missing books. It may be well worth the extra time to figure out how to extract random items from your library’s ILS to complete your sample.
Management of Sampling Surveys
Once librarians are laying hands on individual books in their sample, what do they look for? They should check the cover of the book for discoloration, peeling, damage. Then they should open the book and look at the pages of the text—are they yellowing, brittle? An archival marking pen may be used to determine whether or not a book is acidic. How is the binding? Are the pages intact? This data can be recorded in a spreadsheet for use of later analysis of the entire sample. Include the item’s call number, place of publication, place of production, publication date, measurements (spine height, cover width, depth of back to front cover, the amount of shelving space surrounding the item, horizontally and vertically); describe the case style, leaf attachment and binding condition, text attachment, acidity, paper strength, and text contrast ; list the damaged pages and describe the enclosure type and condition; record any additional notes that will be useful for future reference and analysis.Costs for sampling 384 random items at the University of Illinois at Urbana-Champaign in 1987 were less than $5000. The UIUC Library employed eleven graduate students from the school of library and information science, who received training and supervision. Each surveyor collected forty samples, 90% of the surveys were completed on the first day in 5.5 survey hours.
Analysis of Results
Information from samples can easily be recorded in Excel or some other spreadsheet program, where simple analysis can be performed. For preservation purposes, librarians want to know the condition of their collections: what percentage of the books are acidic? What percentage of the collection is damaged? Does more damage take place on cramped shelves? Does the library need to be concerned with books printed in Eastern Europe? Etc. After identifying the issues of primary concern in the collection, preservation measures should be considered. What needs to happen as soon as possible to preserve the collection? What choices can be delayed for some time? Does the library have a preservation plan in its collection management policy? Is there a budget for maintaining the collections? What can be extrapolated from the data about what might happen to the collection in ten to twenty years?Using the results of the library’s collection assessment, budgetary requests can be substantiated by data. The library needs an increase in budget to care for aging collections, or the library needs an increase in funding to add new materials for our students to meet deficiencies and weaknesses. This strategy was employed by the Joyner Library at East Carolina University
East Carolina University
East Carolina University is a public, coeducational, engaged doctoral/research university located in Greenville, North Carolina, United States. Named East Carolina University by statute and commonly known as ECU or East Carolina, the university is the largest institution of higher learning in...
after an inventory and shelf-analysis project in 2005.
Other Uses of Sampling in Library Collection Management
Sampling can also be used to calculate optimum intervals for shelf reading. Average misplacement of books on a shelf in a university library is 5.6%. 65 percent of the books were located on the correct shelf, but not in the right order. Cooper and Wolthausen developed equations indicating that the optimal shelf-reading interval is a function of the number of books in a section, the likelihood that a book in one section will migrate to another, checking and users costs, and the error rate of the shelf reader.Footnotes
ADDITIONAL REFERENCES
Baird, Brian. Library Collection Assessment through Statistical Sampling, The Scarecrow Press, Lanham, MD, 2004.
Ernick, Linda. “Floating Bibs and Orphan Bar Codes: benefits of an inventory at a small college.” Library Resources & Technical Services, 49(3), 2005, pp. 210-216.
Henige, David. “Epistemological Dead End and Ergonomic Disaster? The North American Collections Inventory Project.” The Journal of Academic Librarianship, 13(4),1987, pp. 209-213.
Shouse, Daniel L. and Linda Teel. “Inventory: catalyst for collection development.” Collection Building, 25(4), 2006, pp. 129-133.
Wild, Judith W. “Inventory at Brooklyn College, 1998-1999.” Library Resourcs & Technical Services, 46(2), 2002, pp. 62-71.