Demand driven acquisitions in academic libraries: A scoping review

Demand driven acquisitions (DDA) have become commonplace in academic libraries, but little is known about how they are assessed. This scoping review provides a comprehensive study of print and electronic monographic DDA programs at academic libraries. The review includes an examination of the definition of DDA programs, methodological approaches, and the impact of DDA programs on established library collections. The research team ’ s goals include outlining the current discourse on DDA and identifying gaps in the existing literature, as well as examining the potential for standardization within the profession regarding DDA terminology and definitions. Of 1758 records, 48 publications were identified for inclusion. Analysis of the included publications revealed most studies examined electronic DDA programs that were considered pilots. Overwhelmingly, the literature studied aspects of return on investment, circulation, and use. More subject points of investigation such as evaluation of materials, satisfaction of users or librarians, and quality were less studied. Further research on aspects of print DDA, how the COVID-19 Pandemic affected DDA, and more recently growing acquisition methods such as evidence-based acquisitions are needed.


Rationale
Academic libraries in the last two decades have increasingly turned to patrons to help build their collections and save funds through demand driven acquisitions (DDA) programs.The general term, DDA, includes a wide variety of formats and resources where a patron initiates a purchase through a tool provided by the library.Some librarians use the term patron driven acquisitions (PDA) interchangeably to describe these programs.DDA was initially deemed a disruptive technology in the collections field, anticipated to ultimately change "...the entire fabric of established collection development procedures" (Goedeken & Lawson, 2015, p. 206).Concerns about the DDA model included overspending, perceived lack of fiscal responsibility, and minimized oversight of selection and acquisitions (Levine-Clark, 2010).And while it was predicted to become widely adopted in research libraries (Goedeken & Lawson, 2015), there were no commonly used standards for how libraries implement this process or how they are assessed (Lowry et al., 2024).
Due to the relatively recent adoption of DDA as a model for collection development and acquisitions, the scholarly record investigating DDA programs is not extensive.Recognizing the advancement of DDA as an acquisition model, the National Information Standards Organization (NISO) DDA Working Group (2014) issued a report addressing the variety of ways DDA could be accomplished, while providing an overview and conclusions with specific recommendations for the implementation and management of DDA programs.Four years later, ProQuest (2018), shared survey results of 449 librarians around the world on the application of DDA in libraries, its return on investment, and its overall longterm sustainability.The examination revealed that 92 % of librarians surveyed stated DDA was the ebook acquisitions model their library used the most (ProQuest, 4).However, DDA was only one of the many acquisition models libraries used to acquire resources and they evaluate the success of these programs in a variety of ways.
The lack of a one-model approach to DDA in academic libraries has resulted in literature that reflects a variety of studies that investigate local effects.While these many studies (Back & Morris, 2021;Breitbach & Lambert, 2011;Davis et al., 2012;Prelitz, 2023) describe specific DDA programs, to date no scoping review has been done to identify commonalities or emerging topics.A preliminary search of Library, Information Science & Technology Abstracts (EBSCO), Google Scholar, and Library Literature & Information Science Index (H.W. Wilson) was performed to confirm no previous review had been conducted on DDA.This scoping review is comprised of studies and case reports about academic library monographic DDA programs with a focus on one or more of the following: format, publication date, cost, patron type, use, loans, fulfillment, and/or selection method.

Objectives
This scoping review provides an overview of DDA monographic programs in academic libraries and how they are quantifiably assessed.The review includes an examination of the definition of DDA programs, methodological approaches, and the impact of DDA programs on established academic library collections.The research team's goals include outlining the current discourse on DDA and identifying gaps in the existing literature, as well as examining the potential for standardization within the profession regarding DDA terminology and definitions.

Methods
Literature about DDA within academic libraries and consortia was the focus of the review, and the methodological model outlined by Arksey and O'Malley (2005) was utilized.In this model, a stepwise approach that identifies the research question, relevant studies, study selection, and data charting is applied in a structured and systematic way to obtain an understanding of the research landscape on a topic of interest (Arksey & O'Malley, 2005).This method was paired with the systematic review software, Covidence, to manage and organize the process of the review into phases that include importing references, title and abstract screening, full text review, and data charting or extraction (see Fig. 1).Taken together, the methodological model and management software guided the review process.
To select studies for inclusion, the work of Peggy Johnson (2013, p. 43) guided the development of criteria, who described DDA as "…the decision to purchase a title [which] is driven by users accessing the A. Monroe-Gulick et al. item's bibliographic record in the local online public access catalog a specified number of times or for a specified length of time."That includes programs that identify as "patron-driven acquisition, patroninitiated purchasing, demand-driven acquisition, or books-on-demand" (Johnson, 2013, pp. 42-43).
Johnson applies this only to the collection of electronic resources; however, this review included both print and electronic.Johnson's DDA model eliminates the use of interlibrary loan or suggest-a-purchase methods of mediated selection, in which users may not access bibliographic data or have direct influence on resource purchases.While materials such as videos can also be loaded in a catalog for selection, this investigation only looks at monographs, print or electronic.

Inclusion and exclusion criteria
As previously discussed, for the purpose of this review, DDA programs are limited to those that use a catalog-based program.Studies that included analyses and assessments of quantitative data related to DDA monographic collections were considered for this review.However, those that comprised or were exclusive analyses of serial publications, including monographic serials, were excluded.Qualitative studies or descriptions of DDA programs that did not include quantitative data were also excluded because they fell out of scope with the main research objective of identifying how DDA programs are quantifiably assessed.
Other article types that did not fit the criteria for this review include systematic reviews, other types of evidence synthesis publications, and opinion papers, poster presentations and slide decks, as well as book reviews and case studies that lacked quantitative data.If studies included analyses of additional programs (i.e., interlibrary loan and DDA), they were excluded because the presence of multiple programs did not allow for clear analysis of only the DDA portions of the studies.Additionally, studies were excluded if they were not set in academic libraries.Finally, studies were excluded at the full-text review stage if they were not in written in English, but not during searching or the title/ abstract screening.No date or geographic limits were used.

Search strategy
The search strategy aimed to locate both published and unpublished studies.Initial searching within available library discovery services helped to develop the strategy's search terms, strings, and approaches.Data collection occurred in December 2022, and additional search updates were conducted in June 2023.A search including controlled vocabulary, key words, and free text was used to identify all relevant sources from the following databases and grey literature: Academic Search Complete (EBSCO), Library, Information Science & Technology Abstracts (EBSCO), Library Literature & Information Science Index (H.W. Wilson), Charleston Conference Proceedings, Library Assessment Conference Proceedings, and the Directory of Open Access Journals (DOAJ).Additionally, Google Scholar was searched and results from the first 13 pages of returns were exported.After 13 pages, the authors were no longer retrieving relevant or new results.No date limit or language limits were used.Authors completed handsearching of the tables of contents of the following journals for the past year: Collection Management, Tech Services Quarterly, The Journal of Academic Librarianship, and Evidence Based Library and Information Practice.Handsearching within this time parameter ensured that newer studies published in key journals after initial data collection were included.All potential sources were added to Covidence at the title/abstract screening stage.A full search strategy for each consulted database is in Appendix A.

Screening of Sources Title/abstract review
The authors identified 1758 citations and then uploaded them to Covidence for deduplication.The study selection process is shown in the diagram (see Fig. 1) and the authors follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews (PRISMA for Scoping Reviews, n.d.).For the initial review, two team members independently screened each of the titles and abstracts of the remaining 1033 citations against the inclusion/exclusion criteria.Any disagreements between reviewers were resolved by a third reviewer.The 216 studies that met the criteria for inclusion progressed to the full-text review.

Full-text review
During the full-text review, two reviewers read the full text of each study and applied the same eligibility criteria as before.For a study to proceed to the next phase of the review, the two reviewers must have agreed that it met the inclusion criteria.The reviewers were required to give a reason for excluding a study, and a third reviewer resolved any conflicts.Ultimately, 168 studies were excluded, and 48 studies proceeded to the data charting phase.

Data charting
A data charting template was piloted outside of Covidence on two articles by two reviewers, and the results discussed by the research team.Modifications were made based on the pilot template, and the final form was created in Covidence.Each of the 48 included studies was reviewed by two independent reviewers, and consensus was conducted by a third reviewer.Once the data charting was completed, the study data were exported from Covidence as a CSV file for analysis.In addition to basic information such as study dates and method, collection characteristics (i.e., publisher, title, ISBN), study data (i.e., price information, loan data), and assessment outcomes were extracted from each study (see Table 1).
Assessment outcomes.For the review, assessment outcomes contained individual measures, along with an open response option to allow for outcomes not captured by the pre-defined list (Table 3).Evaluation of materials purchased is the inclusion of a quality measure of items purchased.Use of collection is the category for all assessment on usage of DDA programs.Return on Investment (ROI) is defined broadly as any measure related to savings or gain measured by the introduction of a DDA program.It did not require official calculation.These would include cost savings, time savings, and expanded access for patrons.Proper support of collection is if an assessment was conducted on the potential negative impacts of DDA programs.For example, studies have found that DDA programs have the potential to decrease diversity in collections.Satisfaction of the program is separated by libraries (internal) and patrons (external).Workflow effectiveness includes any measurement of the process of the DDA program.Quality assessments, separate from material evaluations, include process appraisals such profiling.Finally, baseline is the presence of other data to assess the effectiveness of DDA programs, not the presence of multiple studies which is an exclusion criteria.

Results
Database searching yielded a total of 1362 publications.Additional searches within grey literature, citations, conference proceedings, open access, and hand searching provided another 396 references.After removing duplicates, 1033 studies were screened for inclusion, and met criteria to be included in the study (Table 1).During the data charting phase, it became apparent that many of the publications either self-identify as pilot studies, or were assessments conducted with first-or second-year data.Fifty-eight percent (n = 28) of publications were pilot, first-, or second-year studies.The remaining 42 % (n = 20) of publications were assessed after that time period.

General study characteristics. The dates of publication spanned 13 years
Collection characteristics & study data.This scoping review defined study data by identifying specific collection characteristics and individual study data characteristics.Collection characteristics included publication information.Most publications coalesced around three key areas: Title (67 %), Subject (56 %), and Publisher (54 %).Study data characteristics (Table 2) included items such as circulation and use data (83 %), information about cost (79 %), or aspects of DDA book loans such as access-to-own (ATO), short-term loans (STLs), or triggers (73 %).Twenty-five (52 %) publications cited these three most frequent characteristics together, with or without other data characteristics reported.
Assessment & impact.As reflected in the assessment outcomes, there was an overwhelming focus on measuring the return on investment (ROI) or cost of DDA collections (92 %), and collection use (90 %).Additionally, half of all publications included in this review (n = 24) aimed to evaluate the materials purchased.Assessing the quality of the DDA program (n = 3), any baseline comparisons (n = 4), proper support of DDA collections (n = 4), and librarian satisfaction (n = 4) were all underrepresented in the included studies.A full list of measurement characteristics is in Table 3 and described in the Assessment Outcomes section above.Impact was determined by reports of changes, recommendations, or plans to change as a result of DDA assessment.Fifty-eight percent (n = 28) of the studies did not report any change or impact because of the assessment.

Discussion
This scoping review provides an overview of the landscape of literature reporting on DDA monographic programs in academic libraries.The review reveals a working definition of DDA and methodological approaches used to assess these programs.In addition, the review offers insights into the impact of implementing DDA programs in academic libraries.

Research question 1: defining DDA
The prevalence of electronic DDA programs in this scoping review highlights the complexity of defining DDA.The studies themselves often did not provide a working definition of DDA but rather focused on characteristics of the collections themselves.The top three characteristics of focus were title, subject, and/or publishers of the available DDA collections.While this is reflective of the data frequently used for assessment, it may also be indicative of the most readily available data.
The terminology used to refer to different programs, with descriptors such as print or electronic added on, is split between demand driven acquisitions (n = 23), patron driven acquisitions (n = 24), and purchase on demand (n = 1).The outlier of purchase on demand is referring to DDA programs under the review's parameters.
The majority (79 %) of the total studies focused on electronic DDA programs, while only 4 % on print.Eight studies (17 %) examined a mix of print and electronic.Reflective of the scholarly record, DDA programs in academic libraries tend to focus on electronic collections.This is not to say that academic libraries have not employed DDA print programs, but this gap in the literature points to both challenges and opportunities in their assessment.This may point to the current pressure on academic librarians to focus on electronic preferred collections with little to no budget, lack of inclusion in consortial agreements, and shrinking staff with limited time.

Research question 2: methodological approaches
The bulk of the studies included in the scoping review were journal articles (60 %), with conference proceedings following at 19 %.Most employed quantitative study designs (65 %), while others employed case reports (17 %) or a mix of design methods (19 %).The study data closely aligned with what each was seeking to assess.For example, many chose to focus on overall use of the DDA collection (90 %), employing circulation/use data to reveal trends (83 %).It is noteworthy that a majority (73 %) of the articles included in this study were from doctoral granting universities, based on the Carnegie Classification.This may indicate budget motives for evaluating usage to contain costs.Across the 48 studies, the average start date of data collection was 2012 with an end date of 2014.These dates reflect that on average, studies focused on two years' worth of data collection for their findings, many as part of pilot programs.Further, the average date range reveals the peak of DDA program implementation in academic libraries.This might suggest that libraries were assessing DDA initially, as programs were being implemented, but have not conducted further assessments beyond pilot, first-, or second-year studies.
Only reporting broad methodological approaches, such as quantitative and case studies, is all that is possible with the information provided in the study sample.Identifying specific DDA assessment methodologies could not be completed because no consistent method could be found.This is due, in part, to the methodological information provided by authors.Many articles lacked details that made it difficult to categorize assessment methods.Even after more than a decade and a half, libraries are still only writing about pilot or short-term data on these collections, unlike the long-standing measures of COUNTER and checkouts.Additionally, since there is not necessarily a standard definition of DDA, it follows that there is not necessarily a standard method of data collection.

Research question 3: impact of DDA
DDA programs gained in popularity amongst academic libraries in the aftermath of the Great Recession of 2008 during a climate of shortstaffing and reduced budgets.The goals were twofold: to save funds and staff time.The studies included in the scoping review reflect this need to prove good stewardship of library resources as they almost all examined the return on investment (ROI) (92 %) and/or use of the collection (90 %).Authors employed data related to cost/price information (79 %), loan types (73 %), circulation/use (83 %), and subjects of titles fulfilled (52 %).Less focus was given to the quality of the product/profiling (6 %), satisfaction of the program by patrons, or satisfaction of the program by librarians.
Even with such a large focus on ROI and use of DDA collections, only eleven (23 %) of the studies focused on workflow effectiveness.The role of the library staff themselves was not as significant as the overall measure of expanded access and cost savings.DDA programs based on loans, such as short-term loans (STLs), access to own (ATOs), and triggers often revealed how use of the overall collection evolved over time.Twenty-eight (58 %) did not result in changes, while twenty (42 %) did result in changes.The changes involved were minor, such as STLs and expanding or decreasing content.Noteworthy is that while minor changes were made, of the articles included in our study, none ceased their DDA programs as a form of acquisitions.

Limitations
There are many terms and phrases used to describe DDA programs.The search might have missed some studies because of potential variations in terminology.While the authors tried to reduce bias in the review by not limiting the search by language, the authors were restricted to only reviewing studies that had abstracts in English and had to exclude studies at the full text that were not in English.This eliminated 26 studies from potential inclusion in the final analysis.The language limitation also leads to a decrease in the geographic diversity of review and that can also introduce bias.The published studies often did not include the dates under examination.An article often stated that it covered two years' worth of data but did not specify the actual dates of the data used.While the publication date gives some indication, the time it takes from study conclusion to publication can vary greatly.Many of the articles did not clearly state their methods.This resulted in not being able to fully analyze the methods portion of the studies.

Conclusions
The results of this scoping review revealed that DDA programs generated significant investigation and scholarship when initially introduced.The majority of articles cover pilot DDA programs-experiments to understand how this emerging trend might work in a specific library or less frequently, a consortium.Cost or ROI served as a dominant concern and purpose for inquiry.Programs often adjusted the structure of their short-term loans based on the value measured in the beginning of a program.This scoping review also shows that electronic DDA is far more commonplace than print DDA.It is evident that DDA programs, print or electronic, are not something that can be presented as a one-model-fits-all approach-each program is slightly different.This is due to several factors, but includes different users, different program needs, different library structures, and different relationships with vendors.The literature reveals that not much has been written about print DDA; this might be an area where institutions with these programs might consider investigation and publication.Most notably, this review found no libraries canceled or phased out their DDA programs.
The conclusions of this study demonstrate that there are unexplored and possible new areas of inquiry related to ebooks, DDA, and other emerging and related forms of acquisition.The articles in this study indicate a lack of investigations that include the perspectives/thoughts of users.However, for those libraries with a print DDA program, qualitative studies might provide important insight, despite the time required to complete such a study.Another topic that could be explored with user perspectives is issues related to DRM/multiple user options.Many DDA programs are based on a one user model.Is this sufficient in an era when more library ebooks are used for classroom instruction?And while not part of DDA, are evidence-based acquisition (EBA) programs or programs to buy front lists affecting or replacing DDA? Lastly, and perhaps something that in time will be investigated, is how the COVID-19 Pandemic affected DDA programs and library budgets.
This study demonstrates that DDA programs, electronic or print, are a common form of acquisitions in academic libraries.The literature reflects two peaks-one when DDA was new and another after plans were revised and on a second round of pilots.The lack of articles in more recent years demonstrates that recent changes, if any, to various DDA programs did not warrant additional study and did not significantly change programs.
Study design.Thirty-one publications (65 %) employed quantitative research design, while remaining studies utilized mixed-methods (19 %) or case reports (17 %).Average data collection began in 2012 and ended in 2014 across all publications, with median start and end dates in 2011 and 2014.The most recent assessment data was collected between 2017 and 2022.An emphasis on electronic collections was evident, with 38 (79 %) publications reporting electronic collection assessment, 8 (17 %) reporting both electronic and print assessment, and only 2 (4 %) publications focused solely on print collections.The two print collection studies assessed data collected from 2011 to 2012 and 2017-2019, respectively.
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Table 1
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Table 1
(continued ) 2010 to 2023.Most publishing on this topic occurred from 2012 to 2017, comprising 73 % of all conducted studies.The number of studies per year is available in Fig.2.Journal articles and conference proceedings made up nearly 80 % of the types of study, with the remainder encompassing reports, trade literature, and book chapters.Geographically, three-fourths of studies were conducted in the United States (75 from %), with others from the United Kingdom (6 %), Canada (6 %), Australia (4 %), and a small representation of other countries (8 %).Institutions were predominantly Doctoral Universities (73 %), assessing collections as single institutions (77 %) or collaborating within formal consortia (21 %) and multi-library partnerships (2 %).

Table 2
Characteristics of studies.

Table 3
Study outcomes.