# Metadata Quality for Biobanks
## 3 State of the Art  
In this section, we review the existing body of work on metadata quality not specific to medical or biobanking domains. Until now, biobank metadata was not addressed in detail as such, so the existing work in this area is limited to the research on metadata describing different kinds of resources, e.g., library metadata or digital heritage resources metadata. In addition, some generalizations are available without any attempts to operationalize the defined concepts for the biobanking domain. On the other hand, the specifications and standards specifically targeting the biobanking domain describe forming the data item attributes connected to biobank samples (this is, e.g., the scope for BRISQ [2]), possibly through the measurement process (codified, e.g., by means of SPREC [1]), as a result, the compliance to such standards can be treated as a sample or data item quality characteristic not related to metadata quality. Furthermore, the MIABIS specification [4], which deals with data structures for describing biobank and biobank collection data, does not currently include the notion of data or metadata quality. A proposal for adding data item quality is currently under consideration. In this section, we limit ourselves to the works which offer the most comprehensive treatment of this topic, postponing dealing with the existing work on concrete quality characteristics and metrics until Section 6, which describes the quality characteristics for the biobank metadata. There, the papers on specific quality characteristics are listed in the corresponding subsections. We do not deal in detail with the papers which provide quality models or further theoretical treatment of the matter; this will be the subject of the follow-up paper. The quality of the semantic metadata evaluation is dealt with in detail by [PERSON] et al. in [17]. The authors introduce the following two-fold definition of the quality for metadata which is founded in ontological knowledge: fitness for capturing of the data sources and fitness in instantiating the ontologies they subscribe to. The authors define the quality criteria for the semantic metadata based on the degree of accuracy in the representation of its three base elements: the data sources, the real world, and the underlying ontologies. A framework for metadata quality assessment is introduced by [PERSON] et al. in [18]. The assessment considers three metadata characteristics with respect to the resources it describes: correctness, completeness, and relevance. For correctness, it concentrates on semantic correctness, omitting low-level (syntactic) correctness. The authors define the logic rules and the approach for combining such rules to form the assessment framework. The rules concentrate on assessing the quality of the metadata description of the dependencies (relations) between the resources. The extensive set of criteria for metadata quality assessment is introduced by [PERSON] et al. in [19]. This paper defines the continuum for metadata quality consisting of the following:  
1. The set of tasks to be accomplished by means of metadata: find entities based on search criteria, identify entities (i.e., confirm that the found entity is the one which was requested), select the entity appropriate for the user's needs, and acquire the selected entity (purchase, etc. );
2. The set of characteristics of metadata quality (referred to as measures, the detailed list of such measures includes completeness, accuracy, provenance, conformance to expectations, logical consistency and coherence, timeliness, and accessibility);
3. The groups of more concrete criteria (questions to be answered) belonging to these characteristics;
4. The compliance indicators for such measures (e.g., the presence of documentation).