- From: Dave Reynolds <dave.e.reynolds@gmail.com>
- Date: Fri, 05 Apr 2013 09:04:44 +0100
- To: Guillaume Duffes <guillaume.duffes@gmail.com>
- CC: public-gld-comments@w3.org, Cotton Franck <franck.cotton@insee.fr>
Dear Guillaume, Thank you very much for your helpful comments on the Data Cube last call. We will give a formal response to the various issues you raise in due course. In the meantime I wonder if I could ask a clarifying question. > _*6.4*_ : “ /In a data set with multiple observations > //*[measures ??]*//**//then we add an additional dimension whose value > indicates the measure. This is appropriate for applications where the > measures are separate aggregate statistics“/→ I do not completely agree > with that. > > First, I guess you meant multiple measures instead of observations. > > The above-mentioned “ /additional dimension/ “, that is the measure > dimension is defined in SDMX 2.1 as “/ is a special type of dimension > which defines multiple measures in a data structure definition. [..]. > Note that it is necessary that these representations are compliant (the > same or derived from) with that of the primary measure.” /The primary > measure which represents the value of the phenomenon to be measured via > a reference to a concept, is mandatory and can take its semantic from > any concept, although it is provided as a fixed identifier (OBS_VALUE). > > The SDMX MeasureDimension is above all a dimension, admittedly of a > particular type, whereas it seems to me that the RDF Data Cube > MeasureDimension, declared as a qb:MeasureType is primarily a measure. > In my mind it is exemplified by the fact that the qb:MeasureType > component is a dimension property with an implicit code list whereas > SDMX requires a reference to an explicit ConceptScheme whether its > representation be made explicit or not. I think it would be worth > mentioning this slight difference. I do agree that qb:MeasureType is unusual in this respect of having an implicit code list, despite being a qb:DimensionProperty. This is called out in section 6.5.2 [1] third paragraph. Is that explanatory paragraph sufficient if we clarify that this notion of an implicit code list for qb:MeasureType is a small divergence from SDMX? Thanks, Dave [1] http://www.w3.org/TR/2013/WD-vocab-data-cube-20130312/#dsd-mm-dim
Received on Friday, 5 April 2013 08:05:17 UTC