ciTIzen-centric DatA pLatform (TIDAL): Sharing Distributed Personal Data in a Privacy-Preserving Manner for Health Research

minor comment

P5L40 The permissions that granted to TIDAL - > that were granted or granted without that

Thank you for the acknowledgement correct the name to Kilintzis instead of Kilitntzis.

This manuscript was submitted as 'full paper' and should be reviewed along the usual dimensions for research contributions which include (1) originality, (2) significance of the results, and (3) quality of writing. Please also assess the data file provided by the authors under “Long-term stable URL for resources”. In particular, assess (A) whether the data file is well organized and in particular contains a README file which makes it easy for you to assess the data, (B) whether the provided resources appear to be complete for replication of experiments, and if not, why, (C) whether the chosen repository, if it is not GitHub, Figshare or Zenodo, is appropriate for long-term repository discoverability, and (4) whether the provided data artifacts are complete. Please refer to the reviewer instructions and the FAQ for further information.

At first, I would like to thank the authors for the detailed responses to all my review comments.
The authors have addressed almost all the raised issues and the paper has been significantly improved.

Please find below some final comments for further improvements:

Introduction: "To achieve this objective, this study takes one step and addresses the research question that what the technical feasibility, efficiency, and scalability of ..."
=> This sentence does not read well, please revise (especially the part "addresses the research question *that what* the technical feasibility").

Section 4, second paragraph: "General users are not required to have any knowledge of Solid specifications, linked data, or writing RDF triples."
=> Again, this does not seem to be true. As shown in Fig. 1 (b), users need to provide URIs (such as https://schema.org/name). How are they supposed to know what URI to provide? Wouldn't be preferable for the users to select a name (not URI) from a pre-defined list and then provide the value (and also be able to easily get additional information about the properties they can provide)? In general, as it is now, the platform does not seem to be operational by non expert users (citizens).

About the queries in each step of the pipeline: The provided "queries" are not queries; they are procedures (code). Since all data are in RDF format, I was expecting to see plain SPARQL queries (e.g., what is the SPARQL query for retrieving the signature and verification key, what is the SPARQL query for getting all data from participants' pods, etc.). Please revise the text (wording) accordingly.

Section 5. The section starts by stating "Given the main design idea of TIDAL that is to **facilitate researchers to access and analyze data from an amount of individual Solid pods,** we designed experiments with three following objectives: ... ..."
This contradicts with the experimental setup. The conducted experiments do no show if researchers are **facilitated to access and analyze data...** (e.g. through a user study). They just show if the platform is efficient and scales well. Please revise the text accordingly.

Evaluation: a user study with real users (researchers) is needed for evaluating the usability of the platform and the feasibility of the whole idea. IMO, this will reveal a lot of usability problems and will allow improving the user interface of the platform. However, I understand that this is impossible to be done in the context of this paper.