The following criteria have been selected to verify whether or not the ‘digital library’ conforms to the Digital Library Reference Model from the Quality domain point of view.
MANDATORY
Regardless of the type of Quality a ‘digital library’ is conceived for, it must meet at least the following criteria:
» A Digital Library (actually its Resource(s)) must be characterised by a set of Quality parameter(s) (hasQuality) and this can not be an empty set.
» Any DL can be considered from a quality point of view by a DL Actor. The expression of the Actor’s assessment is the Quality Parameter.
» Every Quality Parameter must represent the assessment of a Digital Library Actor, whether human or machine, on a Resource (expressAssessment).
A Quality Parameter is always the expression of an assessment made by an Actor on a Resource.
RECOMMENDED
Additional desired properties of a ‘digital library’ are:
The use of a persistent identifier ensures that each Quality Parameter is distinguishable from the remaining ones in the context of the same ‘digital library’.
The digital representation of a Quality Parameter ensures its controlled description, management and use within the Digital Library. This representation is a prerequisite for a series of other automatic actions including the assessment of Digital Library content and services, and quality interoperability.
In accordance with a selected Measurement, a Quality Parameter should have a specific value (e.g. the Measure).
Any Quality Parameter should be managed by the Digital Library according to different Measurements, which provide procedures for assessing different aspects of each Quality Parameter and assigning it a value.
The Digital Library should have policies governing the evaluation and the assessment of its systems and facets.
OPTIONAL
Finally, a ‘digital library’ may also meet the following set of criteria:
A Quality Parameter may be organised in arbitrarily complex and structured forms, e.g. a Quality Parameter may be the compound of other specific Quality Parameters.
Quantitative Measurements are based on collecting and interpreting ordinal data.
Qualitative Measurements are applied when the collected data are categorical in nature. Although qualitative data can be encoded numerically and then studied by quantitative analysis methods, qualitative measures are exploratory while quantitative measures usually play a confirmatory role. Methods of Qualitative Measurements that could be applied to a DL are direct observation; participant observation; interviews; auditing; case study; collecting written feedback.
This is a family of Quality Parameters reflecting the variety of facets that characterise the quality of the ‘system’ in its entirety, in particular the Digital Library, the Digital Library System and the Digital Library Management System.
A Quality Parameter which reflects the variety of facets that characterise the quality of the Content, in particular Information Objects, in a Digital Library.
A Quality Parameter which reflects the variety of facets that characterise the quality of the Functionality, in particular Functions, of a Digital Library.
A Quality Parameter may assess Actor profiles and User behaviour of a Digital Library.
A Quality Parameter which reflects the variety of facets that characterise the quality of a set of Policies.
A Quality Parameter may assess the aspects related to the Digital Library System Architecture. The presence of good administration tools is crucial for configuring and monitoring the functioning of complex and distributed systems.