Participatory Exhibition-Viewing Using Augmented Reality and Analysis of Visitor Behavior

Round 1

Reviewer 1 Report (Previous Reviewer 3)

Many of the issues of the past submission have been improved.

The only hypothesis is presented in the section 4. Data Analysis. I think this should appear before in section 3. Methodology.

Also H1 states that : The distances and durations covered in exhibition-viewing and message mode showed significant differences, which then the results showed differences not to be statistically significant. Then a path analysis is presented, but it has no corresponding hypothesis or research question, so one should be provided for consistency. 

English is readable

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

The paper entitled Participatory exhibition-viewing using augmented reality and analysis of visitor behavior is OK. I have only one suggestion about text breaks. Table 2 should be in full on one page, not cut in half. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

The main contribution of this paper is the creation of an innovative participatory exhibition-viewing system utilizing augmented reality. There is also a detailed analysis of visitor behavior to explore the impact of different viewing modes on audience interaction and participation. The paper is interesting although there is no real innovation. It is well written with convenient images.

It would be important to compare in details your approach with similar studies.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report (New Reviewer)

Augmented Reality (AR) is a technology with high potential to revolutionize how users access and enjoy cultural and educational products. However, the traditional, passive approach limits users' interaction and engagement, focusing more on a personal dimension rather than on collective experiences. Therefore, identifying such a gap in the way AR is often employed in many exhibitions, this study investigates how to enhance visitors' experiences through an AR-based participatory exhibition-viewing system developed for an ad-hoc space within the 2022 Greater Taipei Biennial of Contemporary Art exhibition hosted at the Yo Chang Art Museum. This mobile app features two modes: a passive exhibition-viewing mode and an interactive message mode, allowing visitors to either view content through an AR lens or leave messages in the 3D space of the exhibition. Additionally, the app gathers data on visitor behavior (supposedly, at least 3D coordinates and related timestamps) to analyze potential behavioral differences in how visitors interact with the exhibition content between the two modes. The findings reported by the authors suggest that the type of interaction does influence visitors' wandering patterns across the exhibition space. Actually, the exhibition mode led to more organized paths aligned with the AR content, whereas the message mode resulted in more scattered, unpredictable paths due to the interactive component of leaving and reading messages.

This work builds upon previous developments by the authors, namely navAR, which is described in their previous scientific papers, identified as references [6], [7], and [8] in the manuscript. Out of the total 24 citations, some cannot be strictly qualified as scientific works, notably those from [19] to [22] and [24]. The former appears to be blog entries, while the latter is a reference to a section of the online version of Vuforia software developer manual. Moreover, these eight references are the only ones published in or after 2019. The rest of the cited works are relatively older, especially when compared to the rapid advancement of AR technology in various other fields.

In general terms, the article is organized according to a well-defined and typical structure, consisting of six sections. The first section is devoted to introducing the problem, its context, its relevance to the field, and a description of the work's main contributions. This is followed by a state-of-the-art review that introduces and discusses the role of AR in exhibitions, along with related topics such as audience engagement within exhibits, analysis of AR benefits, and AR positioning. The methodology section describes the implementation and functional features of the AR app. The data analysis section provides a general overview of the main results achieved. The discussion and conclusions sections offer insights derived from the analysis and suggest possible extensions for future work. The essence of the article leans more towards practical application than theoretical discussion.

The topic and results described in the manuscript under review may be of interest for suggesting possible ways to improve user experiences in organizing future exhibitions. However, this reviewer has some major concerns about accepting the manuscript for publication. I strongly suggest that the authors make significant changes and fully address the considerations described below before undergoing another review process.

1. The authors claim four main contributions to the advancement of the AR in the field of visitors’ engagement in exhibitions: development of a participatory exhibition-viewing system; in-depth analysis of visitors’ behavior; enhancing the social value of interactive sociality; improvement over existing works (lines 85-104). In this reviewer's opinion, only the first contribution has been adequately addressed in the manuscript. The methodological approach to analyzing visitors' behavior (section 4.3) is notably lacking, making it difficult to substantiate many of the related claims made in the discussion section. The last two contributions are presented in similar or equivalent terms, and they could be combined. Additionally, the reference to the social dimension does not seem to be factually supported by the descriptions provided throughout the manuscript. where visitors can leave and explore messages. The interactive functionalities describe the message mode as a digital guestbook where visitors can leave and explore messages. While this may be an interesting feature, it falls short of the social interaction, connection, and engagement mentioned in various parts of the text (e.g. lines 88-89; 98-99; 102; 172; 412). Specifically, this reviewer finds the lack of active mechanisms for establishing social relationships among different users to be a significant drawback, since this feature has the potential to add real value to experiencing exhibitions through AR applications.

2. In section 2, a critical review of relevant exhibitions where AR has been used to enhance user engagement would be valuable to read, in addition to the current review of scientific literature. This review should highlight both commonalities and differences with the proposed work. If one of the main innovations of this work is the active mode of interacting with exhibition content, it is worth discussing that past experiences may have relied solely or mainly on passive AR interactions.

3. The first part of the related work section (lines 110-150) introduces several relevant considerations for applying AR technologies in exhibition experiences (e.g. technological integration, quantifying the impact of such technologies on audience engagement, content creation). However, the authors do not explore these issues in depth, often citing one or two examples at most for each. Audience engagement seems to be the only dimension extensively covered in section 2.1, among the issues mentioned before. Similar sections would be beneficial for the other introduced issues.

4. In section 2.2, reference [3] is attributed to Lee et al. but according to the corresponding bibliography entry, it should be Diaz. In the same section, lines 202-204 and 206-209 present some repetitions.

5. Section 2.3 includes references that should be more directly linked to their sources and allow interested readers to seek for more information. This is the case for ARCore, ARKit, Google I/O 2018, and Vuforia. On the other hand, blog posts from commercial sites (e.g. [19]-[22]) should be avoided or limited in the bibliography. If citing these sources is somehow unavoidable, please include an URL to access the article and the date of the last access to it.

6. Regarding AR positioning described in section 3.1.1, it is unclear whether the methodology applied represents a novelty, as claimed in the last line of the abstract. The positioning system used for this work has been adopted from Unity’s AR Foundation technology (line 269), but no mention is provided about any improvements to this commercial system. Authors are invited to describe any of such improvements or clarify what they mean by 'novel' (e.g. whether in terms of technology or application/deployment in the context of exhibitions). Additionally, the sentence at line 264 (“There were only simple text introductions of the centers…”) is unclear to what the authors are referring.

7. In section 3.1.3, it is stated that “The coordinates of the visitors’ smartphones in the 3D space were collected every three seconds” and “The duration between the timestamps of two consecutive coordinates was calculated and summed to represent the total time spent”. Computing the differences between two timestamps seems unnecessary because of the fixed period (3 seconds). If there is any other reason for this calculation, please, provide more details.

8. Are the messages displayed in Figure 5 actual messages by visitors or are they a sort of “proof of concept” to showcase how they would appear on the device screen? Some of them (e.g. comments, three, bonus) seem quite peculiar.

9. In section 3.2, authors declare that “The experiment duration coordinated with the exhibition period (October 28, 2022, to December 30, 2022), all participants were randomly selected from the general public who attended the exhibition. Consequently, convenience sampling was employed.” Why was such a small sample of users selected? Since the app was available on well-known app stores, one might expect that visitors could install it on their devices and participate in the experiment. Furthermore, more clarifications about the rationale behind the random selection of participants and the concept of “convenience sample” are requested. The lack of selection criteria might result in considering unbalanced samples of users under different conditions (such as genre, age, previous experience with AR, to name a few). In turn, this could affect the representativeness of the population under analysis (i.e. exhibit visitors) and the generalizability of the outcomes.

10. The data analysis section provides insufficient details on the analysis process. Authors should include an in-depth and justified description of the overall process, along with the software used for it. Questions that need an answer include, but are not limited to: what units of measure were considered for distances and duration (Tables 1 and 2)? How were the distance measures computed: by considering all the three dimensions or making an analysis one dimension at time? How was the path analysis performed? What do the descriptive statistics of the raw data indicate? How many outliers were detected? Were they removed during the analysis process? The large standard deviations presented in Table 1 suggest possible issues about data reliability, while the reported standard error mean seems to suggest that average values are reliable. Authors should interpret these findings and provide some explanation also to the data reported for the message distance.

11. Section 4.3 is intended to describe the path analysis process, but a description of the overall methodology followed is missing. Additionally, the authors present in figure 7 the path distributions of all visitors. Clarifications are requested concerning what the colors represent (a legend is missing) and how the results described in lines 373-376 can be observed/inferred from the different views, since at a first sight, they look quite similar in shape and distribution. The orthographic view shows some points positioned significantly above/below the frames on the wall. This raises some additional question on the interpretation of this behavior and the precision of the AR positioning system. Have the authors performed some tests to assess its accuracy? Are there any reference on this point? Have the effects derived from the heterogeneous devices employed by users been considered? Were such points excluded from subsequent analyses?

12. In the discussion section, authors claim that “Additionally, from a technical performance perspective, our AR system also showed notable advantages in stability and user-friendliness.” (lines 401-402). However, these aspects have not been considered in earlier sections. A description of the analyses supporting such assertion should be added.

13. The interpretation described in lines 403-409 cannot be directly corroborated because the overall analysis process has not been fully disclosed. A similar consideration holds for the first paragraph of the conclusion section.

14. During the review process, an attempt to access the data by following the link provided in the data availability statement led to a page (presumably in Chinese) from which it was not possible to download any dataset. Please, check this issue and provide a valid URL to access the data.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report (New Reviewer)

The authors have submitted an updated version of their manuscript, which shows significant improvements. Nonetheless, I have found that not all the issues identified during the initial review process have been comprehensively resolved, as detailed in the points that follow. My major concerns are for points 3, 10, 11, and, partially, 9. Additionally, there are some inconsistencies between the responses provided by the authors and my findings upon reviewing the manuscript, such as per points 1, 5, and 12.

I suggest that the authors undertake a further round of substantial revisions to address these concerns and discrepancies before their work can be considered for publication.

---

[In the following, points numbering refers to that used in the initial review.]

Point 1 – The abstract still refers to enhancing the sociality dimension (lines 30-31). In Section 1 there is a reference to “promoting social interaction among viewers” (lines 87-88) and “focusing on shared social experiences” (lines 94-95). Section 2 states that the developed system “strengthens social participation” (line 488).

Point 2 – Section 2.1:

- A request was made for a critical review of relevant exhibitions where AR has been employed to boost visitor engagement. Unfortunately, this aspect was not sufficiently addressed. This section offers broad observations on engagement strategies within exhibitions, rather than a focused review of specific intances where AR technology has been applied. It falls short in providing detailed examples of exhibitions or methodologies that employ this technology, or the tools used to develop and deploy AR-based, interactive content that allow visitors to have a more active and social role.

- Repetitive content was found in lines 128-133.

- After the initial definition of an acronym, such as “Augmented Reality (AR)”, please avoid repeating its full form for clarity and conciseness.

Point 3 – Section 2:

- The authors mention that: “Although AR technology brings new possibilities to exhibition experiences, challenges remain in terms of technological integration, measurement of engagement, user acceptance, and content creation and management. Through an in-depth exploration of these key issues, our research not only fills gaps in the existing literature but also provides direction and foundation for future research in the field of AR exhibition experiences. The following will conduct a literature review focusing on audience engagement with exhibits, AR benefit analysis, and AR positioning technology.” However, there seems to be a misalignment between the challenges outlined initially and those discussed in the concluding section of the paragraph (as per highlighted terms).

- In my prior feedback, I recommended the inclusion of sections analogous to Section 2.1 to thoroughly examine these challenges. It appears this suggestion has not been fully implemented (at least concerning the aspects considered in lines 118-120).

- To provide clear guidance to the reader, I suggest to revise the concluding sentence of the referenced paragraph to directly link each discussed topic to its corresponding section (for example, "…audience engagement with exhibits (Section 2.1)”)

Point 4 – OK

Point 5 – Reference 20 (i.e. Developers, G.f. ARCore. Available online: https://developers.google.com/ar/ (accessed on 2024/4/4) ) is not an academic paper. Reference 22 (Developers, G.f. Keynote. 2018, https://www.youtube.com/live/ogfYd705cRs?si=aIgesbpKLv700oKLig&t=5099) refers to a video on YouTube and the access date is missing.

Point 6 – OK. Please remove the “ at the end of line 267.

Point 7 – OK

Point 8 – OK. In line 322, where the authors note that "some messages might appear peculiar," it would be beneficial to provide specific reasons or examples behind this statement, enhancing the reader's understanding.

Point 9 – OK. While I remain skeptical about this approach, I am interested in knowing if demographic information was collected during the downloading and/or registration phases. Analyzing these data could significantly enrich the understanding and generality of the results by providing a clearer context.

Point 10 – OK. However:

- The authors mention utilizing a behavior analysis system developed by their team to plot three-dimensional path diagrams. Unfortunately, they did not provide any detailed description of this system. It is crucial to include references and at least a basic overview of this system, such as the algorithms used, methods for calculating densities, and how shapes and distributions' similarities are computed. This information is necessary to lend credibility to statements like “The analysis aimed to visualize and quantify the paths taken by visitors, distinguishing between the exhibition-viewing mode and the message mode” (lines 434-435).

- Figure 7 lacks clarity in conveying trends and patterns due to the excessive use of colors for paths (with potential color overlap for different visitors) and generally cluttered visual encodings. The authors' response to feedback on this figure suggests an intention to showcase variations in visitor movement, focusing on areas of high concentration versus those less traveled. However, this intention does not clearly manifest in the current representation. It may be more effective to present a reduced number of trajectories, perhaps by clustering them to explicitly show the diversity in exhibition engagement. Additionally, employing transparency in overlaying trajectories could help highlight the most common paths, making the data more accessible.

- It is also recommended to include units of measurement in the tables to enhance clarity and understanding.

Point 11 – OK. Despite mentioning the execution of preliminary tests to evaluate the accuracy of the AR positioning system, the authors have not elaborated on the methodology employed in these tests. They note that the tests accounted for variances possibly introduced by different smartphone models and operating systems used by visitors. The purpose of these tests was to validate the reliability of the data gathered for path analysis, with points significantly deviating due to potential AR positioning errors or hardware inconsistencies being scrutinized and, if found not to reflect actual visitor movement, excluded from the final analysis (lines 443-448). It is important for the authors to detail how this analysis was conducted and summarize the key findings. Additionally, the authors should clarify their criteria for identifying and justifying the exclusion of outliers from the dataset.

Point 12 – References to stability and user-friendliness are still present in the current version of the manuscript (line 478).

Point 13 – There are still some flaws about the interpretation of some of the stated results, such as those highlighted in points 10 and 11 above.

Point 14 - OK

Even if I am not fully qualified to judge the English quality, I found the manuscript well written and understandable. Minor editing is however suggested. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

AR and XR in general and their use in cultural heritage have already been the focus of several research initiatives. There are however many issues remaining unexplored and there is a concrete need for (1) design guidelines and (2) tools and methodologies for evaluation. In this sense this work has the potential to contribute significantly in the field. In its current form, however, there are several issues that need to be improved:

(1) The focus of the paper is not clear. The introduction and first part of the related work focus on AR evaluation and a logging system that can facilitate this process. Then the second part of Related work on  positioning systems. Then an experiment comparing a viewing and a participatory mode is introduced. There again there is focus mostly on technical aspects- software developemtn approach, posititiong, etc. The experiment focuses on the visitor path length and duration of use and these are the results reported, very briefly and discussed in bullet points.

Taking this into account, the paper would benefit from setting a clear focus and perspective and attempting to support it throughout. If the authors select the perspective of comparing passive viewing with participatory activities, then they should appropriately update the Introduction and Related work. Social interaction, synchronous or asynchronous and participatory activities are topics of research with several and interesting publications, including, among many others, 

Callaway, C., Stock, O. and Dekoven, E., 2014. Experiments with mobile drama in an instrumented museum for inducing conversation in small groups. ACM Transactions on Interactive Intelligent Systems (TiiS), 4(1), pp.1-39. DOI:https://doi.org/10.1145/2584250

Aliakbar Jafari, Babak Taheri, and Dirk vom Lehn. 2013. Cultural consumption, interactive sociality, and the museum. Journal of Marketing Management 29, 15-16, 1729-1752.

John H. Falk, and Lynn D. Dierking. 2008. Enhancing visitor interaction and learning with mobile technologies. In Digital Technologies and the Museum Experience: Handheld Guides and Other Media, Löic Tallon and Kevin Walker (Eds.). AltaMira Press, Lanham, 19-33.

Pradthana Jarusriboonchai, Sus Lundgren, Thomas Olsson, Joel Fischer, Nemanja Memarovic, Stuart Reeves, Paweł Woźniak, and Olof Torgersson. 2014. Personal or social? designing mobile interactions for co-located interaction. In Proceedings of the 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational (NordiCHI ’14). Association for Computing Machinery, New York, NY, USA, 829–832. DOI:https://doi.org/10.1145/2639189.2654840

The methodology of this experiment would benefit from an expanded description of the two different approaches and the reasoning for comparing these approaches. Asynchornous social interaction and content viewing and exploration are not antithetical and should not be compared as such. It is also not clear if the messaging version also allows for content viewing. 

The paper is well writen and easy to read in terms of language.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

It is better to revise abstract, and mention the progress made in the field and the existing challenges.

The authors should clearly mention the contributions in the introduction section.

The proposed method should be compared with state-of-the-art methods (if exists).

Quality of English language can be improved.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

The authors describe an interesting study case of AR application in an art exhibition. 

my major concerns are: 

1) the introduction and related work section should give the reader a clear idea of what has been done before on AR in general and AR in art exhibitions in particular. Such a description should be deep enough or focused on supporting the actual paper hypothesis and experimental design. It is true that some related works are mentioned but were not detailed their AR design, environment settings, effects measured, instruments used, research questions or their main findings in order to frame the current research. Such description is not only a matter of giving more details but focused on the study aim and hypothesis. 

2) The related work section is not aligned with the working hypothesis. For example, section 2.2 focused on AR positioning. However, this aspect is not the focus of any of the 2 hypotheses. Part of that description and analysis could be better presented in the discussion section to partially explain the reasons for some aspects of the results.  

3) the 2 user modes should be supported in the related work. Why those and not others?  seems that in the message mode, the messages are in the spacial 3D environment but without the AR objects of the pictures as in the previous mode. So why this way and not mixing both? Has this way been done before? 

4) experimental design: participants description: the description starts talking about 130 visitors per mode approx. but after discarding visitors that used only one mode + invalid samples the final considered participants were 61 visitors. The reasons for discarding 1 mode visitors are not clear. Why not incorporate them as a factor/condition? It also poses a bias on the results that at least should be mentioned in the limitations section. Also from those 61 participants, 53 were under IOs and only 8 under android. That leverages another possible bias due to the device used together with some concerns on possible technological problems. 

5) Results: measures are not clearly explained. That is, how do you measure or calculate distance and duration is not clear. Also table 1 provides descriptive statistics per measure, but not per condition (used mode). This severely restricts results comprehension and replicability.  

6) hypothesis: null and alternative hypotheses were provided. Only one of them is enough. Its actual form does not encourage readability. Perhaps it is better to use research questions due to the explorative nature of the study. 

7) discussion: it is too brief (the limitations section is larger!!). It is also too focused on the implementation difficulty of some AR technological aspects and not on analyzing the results focused on the working hypothesis. That is, try to explain why there were no differences in duration but were on the distribution among used modes, and what factors (technological, environment settings, personal/emotional, etc) could have influenced that behaviour. 

7) research objectives and main contribution should be clearly given to the reader in the introduction. 

English needs some editing

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

Although I commend the authors' effort on documenting their work and on writing this report, I fail to see any significant novelty on their conclusions and on their methods. Therefore, I would not recommend publication of this work on its current status.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Most of the points were partially or not corrected. 

Below is the point-to-point review:

Point 1: the introduction and related work section should give the reader a clear idea of what has been done before on AR in general and AR in art exhibitions in particular. Such a description should be deep enough or focused on supporting the actual paper hypothesis and experimental design. It is true that some related works are mentioned but were not detailed their AR design, environment settings, effects measured, instruments used, research questions or their main findings in order to frame the current research. Such description is not only a matter of giving more details but focused on the study aim and hypothesis.

Response 1: Thank you for your suggestion. I have added a section specifically discussing Audience Engagement with Exhibits and social interaction in line 81 to line 104.

RR: the added text describes the relevance of audience engagement and social interaction. However no details on their AR design, environment settings, effects measured, instruments used, research questions or main findings were provided of those past works. The sentences on lines 82-88  have no references although it seems to be providing information of other works.

This also happends in the new intro, lines 36-51. There are many ideas and statements, but without any reference to support it.  

2) The related work section is not aligned with the working hypothesis. For example, section 2.2 focused on AR positioning. However, this aspect is not the focus of any of the 2 hypotheses. Part of that description and analysis could be better presented in the discussion section to partially explain the reasons for some aspects of the results. 

Response 2: Thank you for your suggestion. I have explained the reasons for some aspects of the results in line 346 to line 352.

RR: some descriptions were moved to the discussion to give support to the findings. However, section 2.3 AR positioning still exists providing technical information on libraries/ frameworks that are out of the paper scope. Also section 3.1.1 is too long, discussing on libraries, issues and problems with AR positioning systems. In this way, the document seems mora a technical report than a research article.

3) the 2 user modes should be supported in the related work. Why those and not others?  seems that in the message mode, the messages are in the spacial 3D environment but without the AR objects of the pictures as in the previous mode. So why this way and not mixing both? Has this way been done before?

Response 3: Thank you for your comment. The rationale for utilizing the current research methodology is elaborated in lines 242 to 251.

 RR: the new text provides more details describing both modes, but no references or justifications for those elections were provided. It is also not clear if these modes are new or have been presented in past literature.

4) experimental design: participants description: the description starts talking about 130 visitors per mode approx. but after discarding visitors that used only one mode + invalid samples the final considered participants were 61 visitors. The reasons for discarding 1 mode visitors are not clear. Why not incorporate them as a factor/condition? It also poses a bias on the results that at least should be mentioned in the limitations section. Also from those 61 participants, 53 were under IOs and only 8 under android. That leverages another possible bias due to the device used together with some concerns on possible technological problems.

Response 4: Thank you for your comment. The final participants consisted of 61 visitors, with one excluded due to a typographical error, which has been rectified. The limitations have been added in lines 369 to 377.

RR: ok

5) Results: measures are not clearly explained. That is, how do you measure or calculate distance and duration is not clear. Also table 1 provides descriptive statistics per measure, but not per condition (used mode). This severely restricts results comprehension and replicability. 

Response 5: Thank you for your comment. The measures have been explained in lines 275 to 279.

RR: the 2 measures have been better explained. But Table 1 still shows incomplete data, as it is providing just an overall mean, missing the descriptive statistics per condition (used mode). This is critical, as the experiment is focusen in searching for possible differences among these 2 conditions. This is a serious flaw as it does not allow for comparability nor replicability.

6) hypothesis: null and alternative hypotheses were provided. Only one of them is enough. Its actual form does not encourage readability. Perhaps it is better to use research questions due to the explorative nature of the study.

Response 6: Thank you for your suggestion. The hypotheses have been combined into one hypothesis.

RR : null hypothesis is still present.

7) discussion: it is too brief (the limitations section is larger!!). It is also too focused on the implementation difficulty of some AR technological aspects and not on analyzing the results focused on the working hypothesis. That is, try to explain why there were no differences in duration but were on the distribution among used modes, and what factors (technological, environment settings, personal/emotional, etc) could have influenced that behaviour.

Response 7: Thank you for your suggestion. I have explained it in lines 346 to 352.

RR: The discussion section cannot be fixed  adding a 7-lines paragraph. It requires a mayor resstructurarion in terms of ideas, arguments, and past research comparisons. The text is still with bullets as in a report!!.  

7) research objectives and main contribution should be clearly given to the reader in the introduction.

Response 8: Thank you for your suggestion. I have mentioned the research objectives in lines 63 to 66 and the main contributions in lines 73 to 79.

RR: there are no explicit research objetives in those lines. A brief description of what done is not an objetive. 

English is readable, although some typos and non-English expressions are present. I recommend proof-edit english.