In 2009, PSNC, the operator of Polish Digital Libraries Federation, began working with Europeana and exploiting the potential of promoting Polish cultural heritage content across Europe with the aim of creating wider access and facilitating re-use of their content. Europeana’s API has provided a good platform for this, both enriching existing services and providing a wider breadth of content to users of the DLW and DLF services. Through a number of widgets, DLW and DLF have utilised Europeana’s API to bring in content from Europeana that is related to search queries on their existing websites. This provides end-users with more choice as results are returned from hundreds of other trusted heritage institutions across Europe via the Europeana API.

1. Case Study: Europeana API Implementation in Polish
Digital Libraries
Open Data Case Studies Workshop
Paris, January 28, 2013
Marcin Werla, Poznań Supercomputing and Networking Center
Overview
Big Idea 2
Users 2
Value Proposition 2
Channels 3
Benefits 6
Conclusions 6
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2. Big Idea
Poznań Supercomputing and Networking Center (PSNC) have been working with Polish
cultural heritage institutions for more than 10 years. This cooperation has primarily focused on
putting the institutions’ digitised collections online, mostly for educational and research use.
The first outcomes of this cooperation were available online in 2002. In 2009, we started
working with Europeana, appreciating its importance and strategic potential to promote Polish
cultural heritage all over Europe and make it even more accessible and re-usable.
In 2010, when the pilot programme for the Europeana API was announced, we had an idea
that, if properly used, an automated way of accessing aggregated data could significantly
increase the visibility of European cultural heritage among the users of Polish digital libraries.
Users
A study conducted in 20101 found that regular users of Polish digital libraries mostly fall into
one of the following categories: amateur historians and genealogists, genealogists, local
historians, academics and students. We decided to use the data available through
Europeana’s API to enrich our base services, without specifically focusing on any of the above
types of users, therefore also addressing incidental users who are not covered by the
mentioned categories.
Value Proposition
While defining the scope of our pilot API applications, we decided that the implementation
should focus on two core functions of digital libraries: searching the available collections and
displaying metadata for particular digital objects. We wanted to enrich the information
presented to users with data about additional but relevant objects found in Europeana. Such
enrichment should be easily accessible, unintrusive and should look like a natural element of
our system.
1
Górny, M., Mazurek J. (2011), “Key users of Polish digital libraries”, Electronic Library, Vol. 30 No. 4, pp. 543-556, available
at: http://dx.doi.org/10.1108/02640471211252238 (accessed 18 March 2013).
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3. Channels
We decided to use two services which are hosted and developed by PSNC:
 Digital Library of Wielkopolska (DLW) – the oldest and second largest Polish digital
library, established in 2002 - http://www.wbc.poznan.pl/
 Digital Libraries Federation (DLF) – Polish metadata aggregator collecting information
about over 1.2 million digital objects from more than 80 digital libraries, archives and
museums (including DLW), established in 2007 - http://fbc.pionier.net.pl/.
We used APIs to access information held by these libraries, in addition to the Europeana API.
To make the integration of API-based extensions into these services as seamless as possible
for the end-users, we assessed their workflow. We assumed that a user’s workflow starts in
the DLF, where he/she is searching for interesting objects. After finding something interesting,
he/she is redirected to a digital library website for a particular object, where he/she finds
metadata and a link to the content. On this basis, we decided to extend DLF search results
with links to search results in Europeana (using the same user query as an input to both
search systems), and to extend the particular object’s results with links to associated objects in
DLF and Europeana. The associations are based on API searches from DLF and Europeana,
using pieces of an object’s metadata as a query. The overview of the initial data and user flow
between the three systems and the flow which we wanted to achieve is depicted in the figure
below.
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4. Finally, we implemented two widgets: ‘More results from Europeana’ for DLF and ‘See also’ for
DLW. These widgets dynamically get data from the website which is then displayed to the
user, the widget also sends a request with this data to the API and displays search results
received from the API as a response. Screenshots below show the final result of such dynamic
enrichment.
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5. Search results on the Polish Digital Libraries Federation website enriched with a ‘More results
from Europeana’ widget based on the Europeana API.
Metadata record on the Digital Library of Wielkopolska website enriched with a ‘See also’
widget based on the Europeana API and Digital Libraries Federation API.
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6. Benefits
The widgets were deployed online at the start of 2011. Almost a year later, we decided to start
evaluating their usefulness by analysing the traffic data gathered by Google Analytics from
Europeana, DLF and DLW. The analysed period was 1 Jan 2012 – 13 June 2012.
During the analysed period, the DLF website had 458,979 visits, of which 323,910 visits
included the search results page. At the same time, Europeana noted 16,754 visits which were
initiated from the DLF website (DLF was the referrer). This means that 5.17% of visitors who
saw search results on DLF decided to click through to Europeana. Moreover, these users
spent double the average time on Europeana. This clearly shows that enrichment based on
the Europeana API not only directed users to an additional source of information, but also that
they enjoyed this additional source.
Similar analysis for the DLW website showed that at least 0.75% of visitors who saw at least
one metadata record during their visits decided to check the suggested objects in Europeana.
The duration of the visit was also significantly higher than the Europeana average, but not as
high as the average duration of visits from the DLF. The significantly lower percentage of
redirections to Europeana from DLW, compared to the DLF ratio, can probably be justified by
at least one major difference between the DLW and DLF widgets. The DLW widget provides
an additional feature to the metadata display website, while the DLF widget extends the core
functionality of the search, thus has a higher chance of being used. Additional traffic data
collection and deep analysis would be required to provide more confident explanation of that
difference.
Conclusions
The aim of this case study was to describe the idea, the implementation and benefits that
PSNC’s Digital Libraries Team achieved by using the Europeana API to enrich the services of
Polish digital libraries. We hope that the presented material is convincing enough to encourage
providers of cultural heritage web services to take a closer look at the Europeana API, and to
consider implementing additional features for their systems based on this API.
As a final remark, it is worth noting that it is not only data providers already cooperating with
Europeana who should be aware of the many benefits of opening their data. As described in
this study, service providers like Europeana and the Digital Libraries Federation are able to
gain significant volumes of quality visitor traffic by opening up their data and functionality via
their APIs. These are valuable benefits that could also be realised by other providers who
open up their data and integrate with other services.
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