Introduction. GEOSS currently contains a large amount of data and is constantly growing, offering its users ever greater choice in datasets. With choice, however, comes a problem of data quality assessment and decision making. To tackle this challenge, the ID-03 GEO Tasks (formerly GEO Science and Technology Committee (STC)) propose to establish a GEO label – that is, a label to certify geospatial datasets and their quality. As envisaged by the ID-03 GEO Tasks, the GEO label is proposed as a value indicator for geospatial data and datasets accessible through the GEOSS. It is suggested that the development of such a label could significantly improve user recognition of the quality of geospatial datasets and that its use could help promote trust in datasets that carry the established GEO label. Furthermore, a GEO label could assist in searching activities by providing users with visual cues of dataset quality and possibly relevance; a GEO label could effectively stand as a decision support mechanism for dataset selection.
Geospatial Data Quality and the GEO Label . When selecting and using geospatial data, users typically need information on its quality. Objective quality information is often found in formal metadata documents supplied by the dataset provider or in technical reports which describe quality checks. Subjective quality information is also available and can include informal reports from other users describing how they used a dataset, users' ratings of data or assessment of data relevance, recommendations for appropriate/inappropriate uses of the data, or supplementary advice from dataset providers, such as warnings about problems in specific areas. At present, most standards-compliant geospatial data has a metadata record, but other (subjective) quality information can be scattered or unavailable. For this reason, the GEO label is proposed as a representation and interrogation facility to combine objective and subjective quality information in one place.
The GEO label itself will be a graphic representation (i.e., a static image) which will be generated individually for each dataset in the GEOSS (or other data portals and clearinghouses) based on the quality information that is available for that dataset. The role of the GEO label in the data selection process can be best explained using a small scenario:
Consider yourself searching for a dataset in the GEOSS (or any other data portal or clearinghouse). You enter a search query and the search engine returns a number of datasets that match your criteria. Each of these datasets is accompanied by a GEO label which visually summarises the availability of quality information for that dataset. This allows you to make a quick assessment as to whether or not the information available suits your needs in terms of making an informed dataset selection. If you decide to investigate a dataset further, you can click on its GEO label and access the actual quality information for the dataset.
GeoViQua's Role . GeoViQua is expected to highly contribute to define the concept of the GEO label so to allow for an increasing trustworthiness over GEOSS data and services delivery. GeoViQua will conduct online surveys, focus groups and controlled structured studies to define the role that a GEO label should serve. We will apply the defined GEO label protocol to the pilot case studies and identify major issues and possibility for improvements.
GEO Label Development. The development and evaluation process will be carried out in three phases:
Phase I: We conducted an online survey (GEO Label Questionnaire) that was looking at:
- Background information about the survey participants, the data sources they use or produce in their work and their awareness of any certificates or seals that apply to geospatial data;
- Initial user and producer view on the role that a GEO Label should serve;
- Some examples of common review and rating systems to identify the participants' opinion on such systems so that we can draw on the strengths of these when developing the GEO Label;
- Some examples of commonly used seals that use click-to-verify functionality and the relevance of such functionality to the GEO Label; and
- Any further comments and suggestions on a GEO Label or its potential role.
We have analysed the results of the GEO Label questionnaire and identified key components that could be included as part of the GEO label functionality.
Phase II: Having already solicited initial opinions from the user community as to the role the GEO label should serve and the information it should convey, we have consequently developed three prototype GEO label visualisations.
Prototype 1 Prototype 2 Prototype 3
To evaluate the effectiveness of the proposed GEO label designs, we conducted a second questionnaire-based study were we presented these three prototype visualisations. The study results revealed the design features and visualisation techniques that convey quality information to users in most efficient and comprehensible way.
Phase III: Currently we are in Phase III, where we are developing a physical GEO Label prototype based on the Phase II results. The physical prototype will be evaluated in a human subject study that will help to finalise the GEO label representation.
More information can be found in the following sites:
Generate your own GEO label: http://www.geolabel.net/demo.html
Information about the GEO label in the standards interoperability forum twiki site: http://twiki.geoviqua.org/twiki/bin/view/GEO_SIF/SifGeoLabel
Open Source for the GEO label: https://github.com/lushv/geolabel-service