Review Comment:
The paper aims to tackle the research question of multi-purpose contextual adaptation in WoT applications.
Authors claim their contributions as follow:
1. A theoretical adaptation framework to support domain-independent multi-purpose adaptation
2. A generic model for/set of meta-rules to generate adaptation rules that will in turn allow to infer ranked adaptation possibilities
3. A comprehensive solution for both designers and experts to efficiently process context models and adaptation rules using an incremental reasoning engine
I think the paper is heading towards an interesting research direction which is motivated by emerging use cases and scenarios. However, the paper's
content and contribution are not sufficient to be published as a full paper in this special issue given that the publishing cycle
of a special issue has a time constraint for the follow-up revisions. Please find my detailed comments in following.
My first concern is how much the work presented in the paper is new when comparing with many other papers of the authors such
[5],[35],[36], [37]. Reading through the paper, there is a lot technical content that are referred to these papers, this makes quite
difficult to justify whether the contributions are contained in this paper. Moreover, it seems authors assume that the readers are familiar with ASAWoO platform
and the project, the concepts like avatar, meta rules, and avatar architecture are not the well-know concepts, at the least to the reviewer.
In overall, the contributions of the paper are not substantial and not well presented.
The second concern is the clarity of the technical details. Authors tend to use various "jargons" without proper explanations and definitions.
There are quite many technical, notation, presentation and formation issues across most of the sections as listed in below.
In Definition 1 for Contextual dimension whereby the contextual dimension is defined via contextual instances and observations. However, contextual instances and
observations are not formally defined. The descriptive definition such as "A contextual instance is a high-level piece of contextual information" with other examples, {Hot, Warm, Cold}
does not provide formal meaning for them. Also, d={i_d}, notation i_d has not been introduced so far, then, " d\in D where DI a the set of available..." ,
if I understand correctly d is a set, then d \in D, that means D is a set of set?, it's a bit confusing to me, the example with Temperature, {Hot, Warm, Cold}
are not properly explained this definition.
In Definition 2 authors define adaption purpose as a set of contextual instance, ap={i_ap}, and then ap\in AP, however, then authors specify AP as a set
with a list of items {Imp,Comp,Exp, Prtc,CdL} which are very odd to me. Again, there is no formal definition them ( {Imp,Comp,Exp, Prtc,CdL} ). From
their descriptive definitions, it's not clear to me whether they are functions or data elements or rules?
The Definition 3 continues the confusion with the definition of "context model as a two-dimensional set of contextual instances...", I think a detailed example
showing how such definitions are represented as real data elements must be provided. The descriptive definitions provided are not proper way to
present what so called "theoretical adaptation framework".
In Definition 4, authors try to ground/linked the above 3 definitions to RDF Triples and SPARQL queries, and transformation rules, however,
the definition of contextual situation does not show a formal relationships with the semantics, notations of RDF and SPARQL. I think all examples
in RDF and SPARQL syntaxes show authors' struggle in mapping formal definitions in Definition 5, 6, 7 and 8 to data and processing logics
and algorithms. This leads to my question why authors did not use notations, definitions and semantics of RDF, SPARQL and OWL for
such formal definitions instead.
The authors state that they "tackle the research question of multi-purpose contextual adaptation in WoT applications", however, the research
question is not clearly defined the paper, and, to the best of my knowledge, it is not a well-known one in the literature. The section 1 on
introduction, the authors just give some leads to the research question by shortly presenting some details of their project. Then, the related work section, authors
spend a lot of space to present various things but the content does not give a clearer picture on "what is the problem?", "why it is a problem?".
Note that authors claim that one of the contributions is a " theoretical framework".
For the statement: "Existing adaptation solutions are either tightly coupled with their application domains (as they rely on domain-specific context models)
or offered as standalone software components that hardly fit in Web-based and semantic architectures.",
is there any strong reference or evidence for this argument, and also it's not clear to me what is "semantic architectures"?
For this statement, "..to comply with Web standards (e.g. resource-oriented architectures, semantic Web, Web of things)...", I don't think "resource-oriented architectures,
semantic Web, Web of things" are Web standards.
In section 4.1.2, authors throw in two jargons " meta-model" and "identical reasoning mechanisms" which I have no clue what they mean.
Authors mention, "reasoning techniques", "incremental reasoning" in here and there but the technical details are not clearly presented in the paper.
For instance, in second paragraph of section 4.2.2, authors mention " At runtime, contextual instances are inserted in and deleted from the semantic repository,
which is equipped with both a SPARQL endpoint and an OWL2 RL incremental reasoner", it's unclear for me why OWL2 RL incremental reasoner is needed,
and why OWL2 RL not OWL 2 QL? In section 7, authors have an explanation in the footnote and just a quick indication processing times, but the details are not substantial.
For section 5, I found that the explanations on how the rule management process work by simply giving examples under SPARQL queries are not
sufficient in terms of technical depth, for example, are they general enough? are they semantically correct?
For section 6 on evaluation, I have a lot of doubts on the evaluation methodology and the outcome interpretation. First, authors claim the correctness
by walking through the examples, and providing example results, then claiming the correctness of the outcomes, I think they are very unconvincing. Besides, I wonder why authors
do not include the evaluations runtime performance, optimisation of adaption of rule set but move them to discussion section 7 instead.
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