Sian Brannon and Karen Harker, University of North Texas


Interlibrary loan (ILL) requests are typically placed because a collection does not have a specific item a user wants. Looking at patterns in ILL requests over time can give the library an idea of demand, titles requested, areas of deficiency, and potential sources to acquire.

Why look at ILL for negotiation purposes?

1) Perhaps you have licensing principles or vendor relations information that covers ILL:

2) You may identify journal titles to consider adding: ILL requests/fulfillments might indicate something that people actually use—both new titles and backfiles—that you could purchase.

3) You could estimate replacement costs for journals to consider dropping: Look at the total cost it would take to fulfill ILLs for a journal and whether you could lock in a particular per article charge you could cancel. Example: If we assume that 10% of people who download an article really want it enough that they would make an ILL request, how much would that cost (e.g., 10% x Number of downloads x Price per article)? Compare that to the annual cost of the product.

4) Indications of need for certain full-text databases or journal packages: ILL data may tell you whether or not you truly need to increase a subscription to full-text, or if you should consider a larger journal package.

5) You may find subjects that you didn’t know were of growing interest to your students or faculty, particularly if requested by multiple persons.


From Barton, Relyea, and Knowlton (2018): “While this practice of using ILL data to select journal titles for subscription seems to be sound at first glance, it rests on two assumptions. The first is that collection development should prioritize acquisition of resources that are expected to be used most often. The second assumption is that prior ILL usage predicts future usage of subscribed content.” In their study, they found “little correlation between ILL requests for individual titles and their later use as subscribed titles” and a “strong correlation between ILL requests within a subject category and later use of subscribed titles in that subject category.”

Patron entry of data in ILL requests means that titles will have many variations, particularly regarding capitalization, misspellings, use of definite and indefinite articles, expressions of “and” (spelled out vs. the ampersand) and use of full word versus abbreviations. Some of this can be done using programming tools (e.g. OpenRefine, Excel), but a certain amount of manual checking is required. These variations make it difficult to identify the true number of requests for each journal title, which is necessary to identify unmet patron needs. You may need to standardize the journal titles of article requests so that all requests for the same journal are represented the same way (see “Data Cleanup Notes” below).

If you are wondering about using ISSNs… that gets tricky. First, there are often errors and inconsistencies in format (with or without the hyphen). Then ISSNs are specific to a journal title, so the request may be for an earlier version of the title.

If applicable, you should consider the roles of consortia in Big Deal cancellations as well as subsequent fulfillment via ILL: Consortial ILL arrangements may help compensate for journal cancellations; if too many consortium members drop a journal, desired ILL use may lose efficiency. Consortia might organize ILL alternatives (i.e., per-article purchasing).

“Post-Big Deal studies looking at interlibrary loan/document delivery impact have shown, in general, that ‘cancellations have a small effect upon overall interlibrary loan usage’ [Knowlton, Kristanciuk, and Jabaily, 2015, p. 4] and that a relatively small portion of expected demand based on prior downloads results in interlibrary loan requests [Scott, 2016; Jones, Marshall, and Purtee, 2013; Pedersen, Arcand, and Forbis, 2014]” (UC Publisher Strategy and Negotiation Task Force, p. 13). Therefore, libraries and consortia shouldn’t shy away from cancellations of package content.

Data and Analysis

Basic Steps

  • Run queries in ILL database to generate journal titles requested multiple times.
  • Determine criteria for recommendation.
  • Download into your favorite data management software (e.g., Excel, Google Sheets, OpenRefine).
  • Clean or “normalize” the titles (see below).
  • Analyze requests data based on selected metrics.
  • Set criteria or thresholds for making decisions.
    • NOTE: This and the above step may be done interchangeably or iteratively.
  • Match against your current holdings, preferably using ISSNs.
    • NOTE: This is the hardest part. You may want to do this only on the most prioritized titles.
  • Make decisions regarding purchase/negotiation of individual titles.

Metrics to Consider

Look at BORROWING data—you want to know which journals you borrow from regularly:

  • # and % of requests
  • # and % of titles
  • # of requests per title
  • # of unique requestors

Other data you might look at:

  • The most active academic departments and their request activity over time. This could show you what subject areas you need to focus on.
  • The most consistently, heavily requested titles, to consider whether you need to add them.
  • Requests by patron status (undergraduate students, graduate students, faculty, staff, unaffiliated, etc.), to potentially prioritize those needed by a certain group.
  • Which peer libraries are used to fill the requests, to consider collective strategizing.
    • See Schares’s 2019 study that provides software to help.


This is an example of the purchase criteria a library might set in order to make acquisition decisions. It will be up to the individual libraries’ needs to determine what criteria they’ll use:

  • ONE of these:
    • Three-year average number of requests is greater than or equal to 5.


  • Exceeding the CONTU guidelines: no more than 5 requests for an article from any one journal publication from the 5 most recent years of publication.
  • AND both of these:
    • Currently have no access, partial access that doesn’t match well with years requested, or unreliable (piecemeal) open access.
    • Variation of patrons: moderate or wide? Less concern should be given to a single person requesting over and over.

Data Cleanup Notes

Consider that many ILL requests are placed on materials already owned by the library. You will need to remove requests that have been fulfilled locally.

Requests recorded in some systems may not be edited for correction of titles. Thus, journal titles may be entered with many variations, particularly regarding capitalization, misspellings, use of definite and indefinite articles, expressions of “and” vs. the ampersand, and use of full word vs. abbreviations. These variations make it difficult to identify the true number of requests for each journal title, which is necessary to identify unmet patron needs. It may be necessary to standardize the journal titles of article requests so that all requests for the same journal are represented the same way. The title used for standardization would not necessarily be the “official” title, but rather the version that is most often represented by the requests.

  • Examples to change:
    • Ampersands (“&”) and “and”—pick one, it doesn’t matter
      • Advanced synthesis and catalysis
      • Advanced synthesis & catalysis
  • Abbreviations—use the full-worded-title
    • Adv Exp Psychol
    • Advances in Experimental Psychology
  • Punctuation does count—pick the one with the semicolon or commas
    • Analysing design thinking
    • Analysing design thinking : studies of cross-cultural co-creation
  • Spaces count, too—pick one
    • Analysing design thinking : studies of cross-cultural co-creation
    • Analysing design thinking: studies of cross-cultural co-creation
  • Match “parts” that make sense—pick the most complete title
    • Atmospheric environment Part B, Urban atmosphere
    • Atmospheric environment Urban atmosphere
    • Atmospheric environment Part B
  • With additional words (often an abbreviation or acronym)—pick the one with the abbreviation
    • Clinical pharmacology & therapeutics : CPT
    • Clinical pharmacology & therapeutics
  • Obvious misspellings or inconsistent spellings—pick the correctly spelled title
    • Communication research
    • Comunication research
    • Cognitive behaviour therapy (ISSN: 16506073)
    • Cognitive behavior therapy (ISSN: 16506073)
      • NOTE: The ISSNs are the same, so it is clear they are the same journal. Pick one.
  • Examples to NOT change:
    • Case
      • Advanced Energy Materials
      • Advanced energy materials
    • Different word, different journal
      • Advanced energy materials
      • Advanced optical materials




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