A Foundation Ontology for Global City Indicators

Tracking #: 1133-2345

Mark Fox

Responsible editor: 
Guest Editors Smart Cities 2014

Submission type: 
Full Paper
This paper defines a generic, reusable ontology that forms a foundation for representing the definitions of ISO37120 Global City Indicators and their instantiation on the Semantic Web by cities. It makes two contributions. The first is to the field of city indicators. The ontology makes it possible to: • create precise definitions of indicators thereby reducing the ambiguity of their interpretation and making them computationally accessible; • represent the “data behind the data” or supporting data, enabling drilling down; and • achieve interoperability, namely the ability to access, understand, merge and use measurement data available from datasets spread across the Semantic Web by providing a standard representation using OWL 2. The second contribution is the successful integration of seven basic ontologies and their extensions. The ontology spans analytical models (e.g., ratios), statistical models (e.g., population measurements), geo-spatial models (e.g., city boundaries), temporal models (e.g., time periods) and description logic models (e.g., definitions of students, teachers, etc.). It also integrates meta-knowledge such as provenance, validity and trust.
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Review #1
By Raúl García-Castro submitted on 30/Jul/2015
Minor Revision
Review Comment:

The paper has improved from its previous version, but I still see it more as an ontological engineering work instead than as a research work. Therefore, I see the paper more suitable to be an ontology paper instead of a research paper.

The paper has been updated and its length has been significantly reduced, mainly by removing figures and one section (rules). This has caused that some comments from my previous review do not hold anymore since the text that dealt with them has been removed. Besides, a new section has been added (methodology) and other parts of the paper have been re-structured. The paper has benefited of these changes.

Regarding evaluation, the evaluations included are still of qualitative nature. The authors have included a new section about the adoption of the ontology, addressing a comment from the previous review.

Regarding one of my previous comments, in the updated paper the author now includes that indicators can be in different scales (nominal, ordinal, interval and ratio). However, the paper still states that indicators are numbers when that is not the case. For example, any value in a nominal scale won’t be a number and a good example of this are Boolean values (hasAirport = False). Instead of saying that indicators are numbers, the author should say that they are values/measurements/other.

It is strange to see references to working papers by the author that partially overlap with the content presented in this paper. I think that instead of citing those working papers, that are expected to change, the relevant parts of those papers should be included in this paper.

Correct in page 21: “have to incorporated” → “have to be incorporated”

Review #2
Anonymous submitted on 11/Aug/2015
Review Comment:

My comments on the previous version of this focused on two aspects: i) the motivating example - student to teacher ratio, and; ii) the combination of individual indicators into a composite indicator. With respect to the latter, the author now mentions (briefly) compensatory versus non-compensatory methods for combining indicators. I agree that the ontology presented in this paper can handle compensatory integration, but I'm not as convinced that it can support non-compensatory integration by simply "represent(ing) indicators as an ordered sequence." Non-compensatory integration is more complicated than this implies; it would be better if the author looked more closely at this literature.

The first issue - the motivating example - is still there, and still not very exciting. It serves well as a illustration, but again I contend that this is a simple, even "toy" measurement problem: what about vague, contested and fluid concepts such as poverty or quality of life? Again, I realize that this example serves the exposition well - showing the "data behind data" etc. But the paper would have more force if there was some discussion of the challenges in applying this ontology for more complex and contested domains.

Review #3
By Mathieu d’Aquin submitted on 13/Sep/2015
Review Comment:

This paper presents an ontology and I think was originally submitted as an ontology paper. The topic of the ontology has some originality to it (focusing on different aspects of city indicator) even if it is based on notions that are present in many other ontologies (some of them cited in the paper). I couldn't see a research contribution here, as this is really the application of a common ontology building methodology (in a way that remains a bit vague) to a particular domain.

*Significance of the results*
Again, the result is an ontology, which in itself might or might not have impact (it is very difficult to assess from the paper, and all we can really see is the list cities in the process of adopting the ontology at the end of the paper). I don't think there are significant research results in the paper. The ontology itself is not clearly evaluated, as it relies on the ability to respond to competency questions, the origin of which is very unclear, on subjective criteria for the evaluation of indicators, the application of which to an ontology seems inadequate, and on the list of ongoing adoption by a few cities.

*Quality of writing*
The paper is reasonably easy to read and follow. It is not in the right format, but that is obviously only a detail. It is clearly not structured as a research paper since there is no indication of what is the expected contribution, research question or hypothesis, and the evaluation is obviously intended as an evaluation of the ontology.

In summary, this is a reasonably clear report on the building of an ontology, but not a research paper. It would make sense as an ontology paper, but would require a much clearer description of the methodology (e.g. where the competency questions come from), of the potential impact/benefits of the ontology, and of its adoption.