Modeling Execution Techniques of Inscriptions

The paper describes a small but very useful fragment of ontology that frames a topic of extreme importance for the study of epigraphy, i.e. the techniques of execution of inscriptions and their various phases. The concept of "phase" as a diachronic overlapping set of events is extremely interesting and the way it is modelled from an ontological point of view it's very valuable, even if still in an embryonic shape. The synergy between ontologies and vocabularies is another relevant feature of the described ontology, being it based on the solidity of existing models but at the same time providing innovative ideas that perfectly adhere to existing schemas.

The paper is well written, clear and well documented. The illustrated diagrams and examples are legible and useful for understanding the logic underlying the defined classes and properties and their mutual relations.

There are some small inaccuracies (e.g., extech:hasExecutionPhase is a subproperty, not a subclass of crm:P31_was_modified_by; on page 3) which however do not compromise the readability and understandability of the work.

Overall this is a good paper, although much remains to be done to strengthen, give solid foundations and fine-tune the presented ontology. We are sure that future works will validly address the task of defining its classes and properties and providing them with appropriate scope notes and an adequate logical-semantic framework.

The paper is improved following the introduction of diagrams that explain the semantics of the ontology and provide clarity over the proposed design choices. In addition, the language and use of English have been corrected, improving the readability of the discussion across all sections. The authors may consider addressing the following points before submitting the final version in order to improve the quality of the discussion and to strengthen the relevance and validity of the proposed ontology.

The introduction mentions five times “this information” without explicitly define what “this” information is about, but it rather lets the reader guess looking footnote 3. I agree that it wouldn’t be useful to repeat here the whole discussion about the complexities relating to the modelling of epigraphic information but at the same time, it would be very useful to highlight the essence of such complexities for the reader to appreciate the motivations behind the proposed ontology design. Such motivations they only become apparent at the end of section 3 when ontology extension examples have been unfolded. The main motivation can be summarised under the limited and nearly monolithic way in which CIDOC-CRM connects E7 Activity to typological information through the P32 property and the requirement for having a finer way to assign the typology of techniques which relate to interaction with the supporting material (i.e., addition, subtraction, alteration, etc.)
The ontology proposes the property extension extech:hasExecutionPhase as subclass of crm:P31_was_modified_by, which is the inverse version of the P31_has_modified and should be written as crm:P31i_was_modified_by. But most importantly the extended version introduces a semantic twist to the direction of the property; where the active role of the relation is now passed to the man-made feature (ie TX1_Written_Text ). Originally, the CIDOC-CRM puts the E11 Modification to the active direction (has modified). Hence, it would be really useful to indicate the semantics of the inverse property of the extech:hasExecutionPhase.
It should be clarified whether or not the entities Tool and Color are also extensions of the E55 Type class and whether the properties usesTool hasColor are extension of the property P2_has_type.

The manuscript describes an ontology that can be used to represent the different execution phases of an inscription, including information on the execution techniques and tools used, and the characteristics of the letters.

The discussion starts by reviewing the two existing models that already consider this kind of information, namely the EAGLE and CRMtex models, both based on the CIDOC-CRM. The authors show how these could be used to model execution techniques and which limitations they have. To address these limitations, they propose an ontology that can be combined with the existing models for a more accurate representation.

This revised version of the paper has increased the detail of the ontology description, while maintaining the helpful examples that illustrate its usage. The examples are not only given in RDF, but also graphically in the form of a graph, which helps to improve their readability. In fact, the readability of the whole article, which was my main criticism of the previous version, has been greatly improve. I only found one particularly long sentence at the very end of the last paragraph of the introduction, "The paper will then expand on this … all in one point of the model", which I though was hard to read and may benefit from splitting it into smaller sentences.

As with the original version, the ontology seems sound and extremely relevant to the field of epigraphy, so no complains in that regard.

In summary, I suggest accepting the paper.