- From: <andrea.perego@ec.europa.eu>
- Date: Thu, 18 Jan 2018 16:14:14 +0000
- To: <bill@swirrl.com>, <public-sdwig@w3.org>
Dear Bill, dear colleagues, Following my comment during last call about verifying whether and how statistical data comply with DWBP [1], I include below a (very) preliminary set of comments on existing gaps and best practices. It is far from being exhaustive, and I apologise in advance for any incorrect statements. However, I think this exercise could contribute to identifying the topics to be addressed in the BP document. Best, Andrea ---- [1]https://www.w3.org/2018/01/10-sdw-minutes.html#x02 ---- ------------------------------------------------- Best Practice 1: Provide metadata Best Practice 2: Provide descriptive metadata Best Practice 3: Provide structural metadata ------------------------------------------------- This is at least partially addressed by the RDF Data Cube vocabulary. The question is whether there's a requirement for additional metadata (as the descriptive ones) compared to those recommended in RDF Data Cube. Anyway, there's also the issue on whether we shouldn't be RDF-centric, especially since there's already a standard used world-wide for statistical meta/data - SDMX. ------------------------------------------------- Best Practice 4: Provide data license information ------------------------------------------------- This is an issue for any type of data, and the question is whether statistical data have or not specific requirements. For instance, SDMX has a number of "fields" that can be used for use conditions - which is usually encoded as free text. StatDCAT-AP has proposed an approach to deal with this, by illustrating how to encode licence URIs in SDMX records via annotations. E.g.: <com:Annotation> <com:AnnotationTitle>dct:license</com:AnnotationTitle> <com:AnnotationType>StatDCAT-AP</com:AnnotationType> <com:AnnotationURL>https://creativecommons.org/licenses/by/4.0/</com:AnnotationURL> </com:Annotation> ------------------------------------------------- Best Practice 5: Provide data provenance information ------------------------------------------------- SDMX covers this with a number of fields - again, by using free text. ------------------------------------------------- Best Practice 6: Provide data quality information ------------------------------------------------- This is already foreseen in SDMX, where data quality is covered by a number of fields. But it is encoded in free text only. ------------------------------------------------- Best Practice 7: Provide a version indicator Best Practice 8: Provide version history ------------------------------------------------- The use of version indicators is already a common practice for some organisations. However, I'm not sure about version history ("how the dataset typically changes from version to version and how any two specific versions differ."). ------------------------------------------------- Best Practice 9: Use persistent URIs as identifiers of datasets Best Practice 10: Use persistent URIs as identifiers within datasets Best Practice 11: Assign URIs to dataset versions and series ------------------------------------------------- RDF Data Cube already recommends this. Another story is about URIs in SDMX and other formats. As for spatial data, using URIs is not a common practice in the statistical domain. It is not a merely technical issue, as it very much relates to data governance. So, it would be interesting to identify best practices enabling the consistent use of URIs without dramatically changing the underlying infrastructure and the existing data management workflow. Tools taking care of this in a transparent way could be a facilitator. ------------------------------------------------- Best Practice 12: Use machine-readable standardized data formats ------------------------------------------------- See comment to BP14. ------------------------------------------------- Best Practice 13: Use locale-neutral data representations ------------------------------------------------- This is addressed in SDMX and RDF Data Cube, where units of measure and approximations are made explicit. But it is not the case for other formats (CSV and other tabular formats). ------------------------------------------------- Best Practice 14: Provide data in multiple formats ------------------------------------------------- To some extent, this happens already for statistical data. The question is whether Web-friendly formats are consistently supported. Another issue is how to facilitate data serialisation in multiple formats. For conversion from SDMX to RDF, there's already some work done we can point to - e.g.: http://csarven.ca/linked-statistical-data-analysis https://github.com/csarven/linked-sdmx http://270a.info/ https://github.com/linked-statistics The same applies to the conversion of tabular data into RDF. Here, however, the conversion usually requires human intervention because of the lack of standardised structures in the source data. ------------------------------------------------- Best Practice 15: Reuse vocabularies, preferably standardized ones ------------------------------------------------- Here we already have SDMX and RDF Data Cube. For CSV or other tabular data, the usual issue is that the semantics of the "columns" is not explicit. The specs of the W3C CSV on the Web WG could help address this problem. ------------------------------------------------- Best Practice 16: Choose the right formalization level ------------------------------------------------- TBD ------------------------------------------------- Best Practice 17: Provide bulk download ------------------------------------------------- This seems to be already a common practice for statistical data. ------------------------------------------------- Best Practice 18: Provide Subsets for Large Datasets ------------------------------------------------- The "data slice" mechanism may be a way of addressing this. The question is whether it is not covering some use cases. ------------------------------------------------- Best Practice 19: Use content negotiation for serving data available in multiple formats ------------------------------------------------- As far as I know, this is typically not done for statistical data, although they are usually published in multiple formats. ------------------------------------------------- Best Practice 20: Provide real-time access ------------------------------------------------- I think this is very much dependent on the type of data we are talking about, and which are the data management criteria. ------------------------------------------------- Best Practice 21: Provide data up to date ------------------------------------------------- This is usually in the mandate of statistical offices. ------------------------------------------------- Best Practice 22: Provide an explanation for data that is not available ------------------------------------------------- This is not a common practice, as far as I know. ------------------------------------------------- Best Practice 23: Make data available through an API Best Practice 24: Use Web Standards as the foundation of APIs Best Practice 25: Provide complete documentation for your API Best Practice 26: Avoid Breaking Changes to Your API ------------------------------------------------- Standard APIs for statistical data exist, e.g.: https://github.com/sdmx-twg/sdmx-rest/releases/tag/v1.2.0 ------------------------------------------------- Best Practice 27: Preserve identifiers ------------------------------------------------- This links to the URI issue, but it includes having persistent identifiers for the different versions of a dataset. This very much relates to data management / governance, storage / archiving capacity, as well as the data update policies. In many cases, old versions of statistical data are not preserved (e.g., in case of high frequency of update, or if the use cases/mandate just requires to provide the most up to date version). On the other hand, the code lists, taxonomies, etc. used in statistical data by statistical offices (as NUTS, NACE, etc.) are maintained by following clear versioning policies - which include also the indication of successors/predecessors, deprecated terms, etc. On this issue, an RDF voc exists, namely, XKOS (http://rdf-vocabulary.ddialliance.org/xkos), which extends SKOS to cover the requirements of statistical classifications - versioning included. ------------------------------------------------- Best Practice 28: Assess dataset coverage ------------------------------------------------- This BP is about archiving/preservation of the data along with the code lists, taxonomies, vocabularies, etc. used. See comment to BP27. ------------------------------------------------- Best Practice 29: Gather feedback from data consumers Best Practice 30: Make feedback available ------------------------------------------------- This is not done consistently, but happens to all type of data. The question is whether there's a specific recommendation for statistical data. ------------------------------------------------- Best Practice 31: Enrich data by generating new data ------------------------------------------------- TBD ------------------------------------------------- Best Practice 32: Provide Complementary Presentations ------------------------------------------------- Statistical data are frequently published along with their visual (graph-based) representations. Any improvement is needed here? ------------------------------------------------- Best Practice 33: Provide Feedback to the Original Publisher Best Practice 34: Follow Licensing Terms Best Practice 35: Cite the Original Publication ------------------------------------------------- This is already done by statistical offices based on agreed rules. ---- Andrea Perego, Ph.D. Scientific / Technical Project Officer European Commission DG JRC Directorate B - Growth and Innovation Unit B6 - Digital Economy Via E. Fermi, 2749 - TP 262 21027 Ispra VA, Italy https://ec.europa.eu/jrc/ ---- The views expressed are purely those of the writer and may not in any circumstances be regarded as stating an official position of the European Commission.
Received on Thursday, 18 January 2018 16:14:41 UTC