While cleaning up old emails I ended up on this scientific article named Metrics to Measure Open Geospatial Data Quality published last year by Jingfeng Xia. Data quality is a topic we discussed before.
From the conclusion: "Because of the uniqueness and complexity of geospatial data, quality control is always a challenge to data providers, managers, analysts and data service providers. Metrics developed to measure data quality need to reflect the nature of the data, and therefore must be diversely structured to handle maps, coordinates, attributes and other types of geospatial data. A list of dimensions with clear and accurate definitions will provide necessary standards for the measurement. When the practice of open access is also considered, several more layers of complexity are added and additional tasks are created to solve issues pertaining to web communication, data usability, data integrity and related issues. Both quantitative metrics based on objective measurement and qualitative metrics based on subjective measurement are essential to the quality control of geospatial data."