Patron - Driven Acquistion (PDA), to German " customer- driven acquisition " is an acquisition model for media in the library world, where the buying decision of customers run out. With this acquisition model the customer is offered a variety of publications, however, are bought only upon actual customer usage of the library.

  • 5.1 Moderated Patron - Driven Acquisition model
  • 5.2 Non - moderated patron -driven model acquisiton


Patron - Driven Acquisition is in the English literature under the following synonyms known: Demand - Driven Acquisition, Patron Selection Programs, User - Driven Collection, Research - Driven Acquisition Model and Patron - Initiated Purchase. In Germany, however, the terminology Patron - Driven Acquisition has prevailed. This acquisition model can be applied both for electronic books ebooks as well as for printed materials in German literature, however, is increasingly related to ebooks.


Using Patron Driven Acquisition is the customer transferred the authority to determine the stock structure, the acquisition by the decisions of a librarian resigns in favor of the stronger user orientation. Another advantage of this model is that the publications of customers can be used "just- in-time" and anywhere.

Historical development

Since the end of the twentieth century, a trend towards ever lower use of the acquired print media by the customer can be seen in loans statistics of libraries. This can be viewed as an opportunity for the emergence of the idea of patron -driven acquisition.

Independently, the idea in North America by the company NetLibrary and in Australia and Europe, the company created by Ebooks Corporation.

Historical development in North America

In order to implement the idea of ​​patron -driven acquisition, by the company NetLibrary 1999, a model was developed that should allow this type of acquisition. It is considered the first Patron - Driven Acquisition model. For this purpose, a contract with the Colorado Alliance of Research Libraries has been negotiated by the company NetLibrary. In 2002 the company took over the company OCLC Netlibrary due to insolvency. Due to the high cost of implementing the contract was terminated by the Colorado Alliance of Research Libraries in 2006, developed a new Patron - Driven Acquisition and brought to market in 2009. During the development of the new model NetLibrary was supported by the e-book aggregator EBSCO Information Services, the NetLibrary in 2010 bought up, the model is further developed and made ​​available in July 2011 under the name of eBooks on EBSCOhost.

Historical development in Australia and Europe

Almost simultaneously, the company Ebooks Corporation was planning in Australia to offer an eBook service for libraries. Based on a collaboration with the Library of Curtin University a suitable e-book platform called Ebook Library was developed in 2001. It was followed by the development of a PDA model, which is officially created in 2004 in cooperation of Ebooks Corporation with Curtin University, the CERN and other scientific libraries (North Carolina State University, Yale University, the Council for Australian University Libraries) in an advisory capacity. The beta version of the PDA model has been tested by Curtin University, taken by CERN in routine operation in 2006 and tested by the Swinburne University of Technology in early 2006 as a pilot project.

In the same year another model to implement the PDA by the company Ingram Content Group Inc. named MyiLibray arose. In 2010 the company brought Ebrary (now ProQuest ) of the same PDA model on the market. Even publishers with their own e- book platforms have developed their own patron -driven Acqusition business models, such as in Germany, for example, Walter de Gruyter since 2012 or in the Netherlands, the publisher Elsevier since 2011.


The Patron - Driven Acquisition model the customer's e -books are provided for use, which has not yet acquired the library. For this, the metadata of e-books that are to be offered on a PDA model, played in the library catalog. If you click on such a e-book, the customer is redirected to a free preview of this e-book.

If the customer decides to use this e-book, a merchant or an electronic lending of e-books is triggered depending on the PDA provider. In both cases, the customer may use the e-book is usually up to seven days. The number of printable pages, however, was limited by the publishers to approximately 20 % of the total number of pages.

Types of Patron - Driven Acquisition models

Depending on whether it is hosted in the implementation of the PDA acquisition process or not, one speaks of a moderated or non - moderated PDA model.

Moderated Patron - Driven Acquisition model

Moderation takes place whenever the library is involved in the last instance in the decision on the acquisition of a title and " reserves the intellectual decision to buy ." Thus, the " actual purchase [ more ] subject to the prior approval of the relevant specialist unit" is. In this case, the library, the decision as to whether the title should be made ​​available to customers via instant purchase or by short-term loan.

Non - moderated patron -driven model acquisiton

If a PDA model not moderated, the acquisition takes place without the intervention of a fully automated library. It " allows the purchase triggering access by users / inside without any restriction ( " Auto Purchase "). Depending on the provider or preferences of library the PDA e-book can be purchased either automatically or initially "borrowed" by an electronic short loan for a limited time. From a certain number of short loans per title, an automatic purchase is also triggered.

Implementation in libraries

Chooses a library for the implementation of the PDA, they must select a suitable provider first of a series of PDA vendors. The business models for the implementation of the PDA are very different from provider to provider and thus also offer variations in the implementation of the PDA. The second decision to be taken by a library is whether the acquisition process moderated or unmoderated to expire. It depends on the degree to which the library user wants to leave the final decision to purchase.


The PDA is an acquisition model whose global spread has occurred only in recent years. In Australia, the concept of PDA is already fully integrated into the traditional book selection process of the libraries. Today, in Australia and New Zealand use 62% of the academic libraries in various forms a PDA model and has done so for more than four years. Also in North America and Britain wins PDA increasingly popular. Some institutions are planning a long future budgets for the realization and implementation of the PDA and many libraries are already experimenting with the system. In North American, academic libraries run pilot projects in which the implementation of the PDA is tested. In some libraries, a PDA model will be used in routine operation since 2010, others are planning to introduce such a model in 2011. Additional institutions state that they want to introduce a PDA model within the next three years. One fifth of the North American public libraries have already been implemented in 2012 PDA and it has become the preferred acquisition model. In Europe, the PDA has not yet been enforced, libraries in the Netherlands and Sweden are exceptions.

In Germany, the PDA is since 2010 in the states of Bremen, North Rhine -Westphalia, Saxony, Baden- Württemberg and Bavaria on the rise: At the university libraries Mannheim, Bremen, Wuppertal, Bielefeld, Würzburg, Research Center Jülich, in the University of Hagen and SLUB Dresden were tested PDA models from different vendors partly from 2010. As of 2012, an implementation of the PDA in the Leipzig University Library, the University Library of Erlangen - Nuremberg and the Bavarian State Library erprobt.Die SLUB Dresden was acquired in February 2012, after a three month trial period, their PDA pilot project, which they connected to the PDA model EBL and EBL Schweitzer realized as a distribution partner, in routine operation. Since June 2013, the 2011 developed by De Gruyter PDA model is used both for e-books as well as print media after a year of testing in the Leipzig University Library.

Acceptance in Germany

In Germany, the benefits of this acquisition model is controversial. PDA Critics fear that PDA may lead to an unbalanced and useless inventory as customers as opposed to librarians had only short-term satisfaction of their information needs in mind and not the long -term population trends.

This opinion is critical, inter alia, in connection with the so-called " banana legend". Here is an entirely meaningless, but complete inventory on " banana" was purchased by an immature PDA model. During the testing of one of the first PDA models an object over the banana industry and research efforts to solve this problem in Colorado led to this " banana" inventory. All thematic titles were clicked and thus acquired by the library. Today's PDA models have long optimized and exalted to such errors, yet keeps the last eight years the memory of that first failed field test.