# Metadata Quality for Biobanks
## 3 State of the Art
For example, for the quality measure of completeness:  
1. the quality criteria reflect the degree to which the element set completely describes the objects;
2. the set of quality indicators is defined to contain application profile and the presence of documentation;
3. the set of improvement suggestions contains only informal advice (better documentation, adding application profiles, cultural change, etc.) Further advancing the ideas first presented by [PERSON] et al. [20], a detailed framework for metadata quality assessment is proposed by the same authors in [21]. A specific approach for measuring quality in metadata repositories was introduced by [PERSON] et al. [22]. The measurement framework introduced by [PERSON] [23; 24] defines three additional sets of metadata quality indicators (as compared to standard measures): supporting functional requirements, patterns and anti-patterns, and multilingualism. [PERSON] et al. [25] deal with digital libraries, i.e., the ones containing digital objects and their metadata. Some quality characteristics such as relevance or accessibility are specified for the digital objects, whereas accuracy, completeness, and conformance are specified for the metadata records, and completeness and consistency--for the metadata catalogs. [PERSON] et al. [16] limit themselves to the issue of the linked data quality; its quality model includes a set of aspects for applying the model; this set includes the metadata aspect defined as referring \"to the information that provides the context and additional information about the domain data or conditions on the usage of data\". Some metadata quality characteristics are listed, such as provenance. An extended set of metrics to assess the quality of metadata in digital repositories was proposed by [PERSON] and [PERSON] [26]. The authors concentrated on quality as fitness for search. The list of quality characteristics does not differ from those presented by [PERSON] et al. in [19], every characteristic is accompanied by a set of metrics that are supposed to be calculated automatically, without human intervention. This set of metrics is applied by [PERSON] et al. [27] to calculate the metadata quality of open courseware. In the context of the quality of metadata for research data repositories, [PERSON] et al. [28] described quality requirements for such metadata (also related to relevance and usability), which can be used to establish a list of corresponding quality characteristics. A survey of work related to the metadata quality of such repositories (concentrating primarily on reference/citation databases) is provided by [PERSON] et al. [29]. [PERSON] [30] offers a survey of metadata quality assessment techniques. In the proposed definition of metadata quality, support for \"discovery, use, provenance, currency, authentication, and administration\" is listed as the most important metadata function. After providing a mapping between quality frameworks proposed by [PERSON] et al. [20]and [PERSON] et al. [19], it distinguishes completeness, consistency, and accuracy as the most commonly used metadata quality characteristics. [PERSON] et al. [31] offer a survey of metadata quality research limited to digital repositories. The authors provide some insights on handling metadata quality in federated environments, where dealing with large volumes of heterogeneous metadata becomes an issue. In particular, it is noted that the metadata considered high-quality locally can become problematic in a federated environment because the criteria applicable in such environments may be different, as well as the purpose of metadata. Furthermore, the assumed knowledge can be lost while going from the local to the federated environment. The authors emphasize the importance of metadata interoperability in such environments. This view is also supported by [PERSON] et al. in [20,21]. [PERSON] et al. [32] and GO FAIR Metrics group [33] (in detail) describe the approach to define metrics exemplifying FAIR principles (findability, accessibility, interoperability, and reusability).