Process & Results

EAST’s first set of collection analysis was carried out in 2015 and focused on the print monograph collections of its 40 founding members, which totaled more than 16 million title-holdings. The EAST Project Team and Monographs Working Group worked with the collection analysis vendor OCLC Sustainable Collection Services® (SCS) and their online analytics tool GreenGlass® to agree on a set of retention rules that were approved by the EAST membership and Executive Committee. In 2017, EAST welcomed a second cohort of 12 libraries to go through a monograph collection analysis, again working with SCS, 9 million titles were analyzed.

Data Collection and Analysis

EAST’s monograph retention efforts are focused on circulating collections that are readily accessible to member libraries. Therefore, non-circulating materials such as special collections, government documents, and serials and journals have been considered out of scope for both sets of monograph analysis.


Working with OCLC Sustainable Collection Services® (SCS) and the EAST Project Team, the participating libraries extracted bibliographic and item level ILS data for in-scope titles. The data was submitted to SCS who normalized it and created the EAST collective collection which was then loaded into the SCS online tool, GreenGlass™. Each of the EAST libraries participating in the collection analysis was provided a logon to GreenGlass™ which provided them access to visualizations of and modeling tools for their local monograph collection as well as the full EAST collective collection of holdings.


For both the original 2015-2016 Cohort 1 analysis and subsequent 2017 Cohort 2, analysis working groups were appointed by the Executive Committee to work with the EAST Project Team and staff from SCS to analyze the EAST collective collection and build a retention model for the retention of titles across EAST.  The online tool provided by SCS, GreenGlass®, greatly facilitated this process as it incorporates a model builder that allows users to specify particular characteristics of the collective collection as well as aspects of the comparison of the collection to the collections of other comparator groups and determine, based on these rules, how many titles need to be retained. GreenGlass provides visualizations and other representations that allowed the EAST libraries to better understand the collective collection, particularly in terms of uniqueness and overlap as well as usage. The model builder was used by EAST to experiment with various retention modeling scenarios and determine what the impact of any particular model would be on the group as a whole and on each participating library. 

The development of the models was an iterative process with feedback on the models sought from the EAST membership essential in understanding what their thoughts were on the definitions of overlap, uniqueness, and usage that the model was utilizing. 

The Cohort 1 retention model was approved by the EAST Executive Committee in June 2016, with the Cohort 2 retention model approved in December 2017.

The EAST Monograph Collective Collection

Some interesting data points about the EAST collective collection:

Characteristic Cohort 1

Cohort 2

Libraries participating in the collection analysis 40 12
Total number of titles 4,749,042 4,470,032
Total number of holdings 16,573,071 8,985,044
% of titles held by only 1 library in the cohort 50 62
% of titles with 10 or more aggregate uses across the cohort 20 42