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3 REQUIREMENTS ANALYSIS
This section illustrates the first stage for the defini-
tion of a software product line (SPL) in the domain
of digital libraries following the methodology defined
in (Corti
˜
nas et al., 2017). First of all, we describe the
domain. Then, we detail the two steps of this stage
(see Figure 3). Finally, we show and explain the fea-
ture model defined as the result of the analysis.
3.1 Description of the Domain
DLs are information systems where large collections
of information are stored in digital formats and of-
fered to the users through one or many interfaces.
This generic definition serves to give an impression
of how wide is the spectrum of information systems
that fit this domain. Usually, these collections of doc-
uments follow the traditional approach for publica-
tions. This is, there are authors, who write works,
published in particular editions. DLs provide an ex-
tensive number of functionalities to manage the col-
lections each one handle, and the different types of
elements that are related such as editions of a work,
collection of editions, parts of works, or standalone
works, as well as the authorities involved, let them
be writers, editors, printers or illustrators, to name a
few. There are DLs that only handle metadata, but
most of them also store digital resources linked to the
elements of their collections, such as eBooks, pdfs,
digitized pages or external links to other libraries.
In order to allow the users to search or navigate
through the information, the metadata of the elements
stored in a DL needs to be extracted and conveniently
classified. Usually, DLs are managed collaborative,
so there is a set of expert users in charge of handling
the elements and their metadata, and there may be
an internal reviewing process among different team
members to ensure that the data updated to the library
is accurate and of quality. This way, there are different
roles for the users, and there may be variable types of
registration for them, including registration through
social networks. Of course, there are DLs without any
users but a unique administrator who manages every-
thing.
The navigation of the web application can be done
through listings or by querying the database. The lists,
forms and detail views of DLs are much more com-
plex than the standard in web applications since there
is a lot of information from related elements involved
in, for example, an edition. Usually, searches area
also quite complex in DLs since the standard user
is normally trying to find something very concrete.
Therefore, the search engine should be able to filter
by any of the attributes of the elements. For example,
the user may want to find an edition of a work writ-
ten by a specific author, published in a range of years,
with some particular text within its content. At the
same time, the user interface needs to be as friendly
as possible, considering the profile of most users, spe-
cialized in literature. Therefore, the design of these
web pages is highly intuitive and transparent.
OAI-PMH is a protocol to share metadata be-
tween information systems through a harvesting pro-
cess done by a server, the harvester, to many clients,
the data providers. It is used to make libraries inter-
operable, allowing small DLs to aggregate their meta-
data collections into a web portal. There are examples
of these portals at different administration levels, such
as Hispana and Europeana. To provide the data from
a DL into one of these portals, called aggregators, the
library needs to support one or many metadata for-
mats. This is, the metadata for the stored collections
needs to be provided following some convection. Of
course, apart from that, the DLs need to implement
the client-side of the mentioned protocol.
There are some DLs in which the geographic
scope is important. To address this, some features
from geographic information systems may be added.
For example, the elements of the library can be shown
on a map viewer, and the users consulting the library
can do queries with filtering the results by some geo-
graphic boundaries.
As we can see, most of the characteristics of this
libraries are quite common, but there is some space
for variability that depends, first of all, on type of the
most important element the DL manages. For exam-
ple, there are libraries whose collections are focused
only on a particular author, like Valle-Incl
´
an Digital
Archive
9
, and therefore in these libraries there is no
point on showing and managing the set of authors;
however, there are also libraries that study the authors
of a particular period, such as the DL for the project
Publishing in Galicia during the Franco Era (1939-
1975)
10
, and then the main page of the library should
be the authors themselves, since they are the most im-
portant element of the library, and not their works.
However, apart from this kind of variations, the at-
tributes to record for the editions, or the authorities,
are mostly the same among DLs, and the components
to view or edit the information are very similar, except
for the particular web style.
9
Archivo Digital Valle-Incl
´
an: https://www.
archivodigitalvalleinclan.es/publica/principal.htm
10
Edici
´
on en Galiza durante a etapa Franquista: http://
ediciongalizafranquista.udc.gal/
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