Interpretative Structural Modeling Analyzes the Hierarchical Relationship between Mid-Air Gestures and Interaction Satisfaction
Round 1
Reviewer 1 Report
Dear authors,
The user satisfaction and acceptance of mid-air gestures is an important topic in human computer interaction, as I agree, that human hands could replace the computer mouse in the future. Therefore your article has a great potential. I am a little confused, however, that you mentioned just Microsoft Kinect and Leap motion devices but not the Microsoft HoloLens glasses as well, since they already give a good insight in future human computer interaction. Further I miss the information, how the participants in the study employed the mid-air gestures? I would expect, that the participants needed to accomplish some tasks using mid-air gestures in order to evaluate their usability. Those tasks were probably standardized and were the same for all the participants. If so, how many gestures were used in your study and what devices has been used in your studies? There are great differences for example in using Leap motion sensor or HoloLens glasses let alone the use of Microsoft Kinect. How did you incorporate this into your study? Did you test the influence of the gesture set size on the participants? I think that this information are crucial for the clarity of your article and should be included into your next version. Beside this you should better describe the two studies you mentioned in the Introduction (line 60). You should also explain the abbreviations at their first use (line 69).
Comments for author File: 
Comments.pdf
Author Response
Thank you very much for your approval of the article. We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript.
Point 1: Therefore your article has a great potential. I am a little confused, however, that you mentioned just Microsoft Kinect and Leap motion devices but not the Microsoft HoloLens glasses as well, since they already give a good insight in future human computer interaction.
Response 1: About only mentioned Microsoft Kinect and Leap motion devices, but not mentioned Microsoft HoloLens glasses, because in the previous mentioned mixed reality type, Microsoft HoloLens glasses is a very good mixed reality products, so I think So I don't think we need to emphasize it separately in the example. But as you said, it provides a good insight into the future of human-computer interaction, and not all people are aware of the products of the industry. Therefore, it was added to the Introduction example to provide more comprehensive content for readers and related researchers. Meta Quest Pro products are also added, and they are well represented. Here is what I have added to the article (line 50-52) : Better-known products, such as Microsoft Kinect, Leap Motion, Microsoft HoloLens glasses and Meta Quest Pro enable users to manipulate the blank interface, they provide good insight into the future of human-computer interaction.
Point 2: Further I miss the information, how the participants in the study employed the mid-air gestures? I would expect, that the participants needed to accomplish some tasks using mid-air gestures in order to evaluate their usability. Those tasks were probably standardized and were the same for all the participants. If so, how many gestures were used in your study and what devices has been used in your studies? There are great differences for example in using Leap motion sensor or HoloLens glasses let alone the use of Microsoft Kinect. How did you incorporate this into your study? Did you test the influence of the gesture set size on the participants?
Response 2: You make a good point that I did not describe this part clearly in the article. There are two places in this article that involve studying participants' use of mid-air gestures.One is 2.3 User Interview Factors, which collects variables related to participants' satisfaction with mid-air gestures. For this section, no restrictions were placed on the devices or specific tasks used by the participants. The specific additions were as follows (line 138-142):However, as mentioned in Chapter 1, many products have mid-air gestures as an input method, and the hardware, functionality, and gesture posture of different products vary greatly. There is no restriction on the products used by the interviewees, in the hope that a more comprehensive range of variables can be obtained to the maximum extent possible.
The other is 3.1 Subjects, where questionnaires were administered to participants and collected for factor analysis. There is a specific set of gestures when collecting the questionnaires, but it is not reflected in the article. To make it clearer for the reader, here is what I added (line 184-189): Mid-air gestures can be classified into static and dynamic [59]. And due to hardware differences, even the same gesture can have a different user experience. However, the diversity and complexity of gesture types can have an impact on the data. Therefore, the most frequently used gesture types of existing products were summarized, and the respondents who had used mid-air gestures were limited to the seven types of gestures in Figure 2.
Figure 2. 7 types of mid-air gesture types.
Point 3: Lines Beside this you should better describe the two studies you mentioned in the Introduction (line 60).
Response 3: To better describe these two studies, specific methods and implications were added （line 67-72）：After using three ways to collect satisfaction influencing factors in the article, there are various and complex interaction methods using gestures and many factors involved in satisfaction, many of which are difficult to quantify directly. By conducting factor analysis to reduce the dimensionality of data, a small number of factors can be identified to explain most of the variance observed in the many observed variables [21].
Point 4: You should also explain the abbreviations at their first use (line 69).
Response 4: You are right, I only considered the conciseness and easy comprehensibility of the expression and neglected to explain that it should be explained at the first abbreviation, which caused miscommunication. I have made changes in lines 70-71 of the article :Accordingly, interpretative structural modeling (ISM) theory was selected to study the influencing factors of gesture satisfaction.
We sincerely hope that this revised manuscript has addressed all your comments and suggestions. We appreciated for reviewers' warm work earnestly, and hope that the correction will meet with approval. Once again, thank you very much for all your comments and suggestions.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear authors!
It was my pleasure to have a week with your paper. Frankly speaking the manuscript from my humble opinion have written with a good English and very easy to read. So the most time of review I spent on thinking what can affect on authors point of view if initial conditions for research could be defined by the different way.
So some suggestions I've decided to left in my review.
1. In introduction you wrote (line 30-32): "The advantage of gesture interaction is that the use of electronic devices is no longer limited to operating through contact screens, mice, or keyboards, but can be completely removed from the operating medium"
Generally you are right - the general tendency of the progress is to make interaction interface between human and gadget as simple as possible. And an ideal case - get rid of it completely. But as usual devil still presents in details. So in further your text you consider hierarchical relationship as result of affection of constant interface and developing of principle recognition for mid-air gesture... But in fact, as you wrote we have the interaction design as 30-th years progress in gesture recognition researches. But I did not see any highlight that over the last thirty years these interfaces (human-gadget) have also evolved substantially. Mouses obtain more resolution, touch-screens can detect more taps, cameras for mid-air gesture recognition get more dpi-resolution. So the question is this evolution as a factor should be taken into account or not? Could you add some words on this matter to your text?
2. ISM acronym - I see it during the whole text more than couple times. I understand that you mean 'Interpretative structural modeling', but I did not see in text the definition for this acronym? Should it be there or not?
3. Lines 144 - 145: "The propor- 144
tion of male and female respondents was 47.43% and 52.58%"
Let's add up these numbers: 47.43% + 52.58% = 100.01 % - it might be misprint in text?
4. Question to Results item: "The overall reliability and validity of the 30-item questionnaire were analyzed".
I have to ask - is it possible to give the readers a reference on data analyzed for this paper? It is usually welcomed when published data is put in the public domain so that readers can also check the published conclusions, if the data are not the subject of any secrecy...
As for the conclusions and conclusion of this article, they seem reasonable and unquestionable according to the logic of the narrative.
Therefore, I believe that the above deficiencies can easily be corrected, and the article itself can be printed in the near future.
I wish to authors success with that and looking forward to see it published soon.
With best wishes, reviewer.
Author Response
Thank you very much for your approval of the article. We would like to thank you for your careful reading, helpful comments, and constructive suggestions, which has significantly improved the presentation of our manuscript.
Point 1: In introduction you wrote (line 30-32): "The advantage of gesture interaction is that the use of electronic devices is no longer limited to operating through contact screens, mice, or keyboards, but can be completely removed from the operating medium"
Generally you are right - the general tendency of the progress is to make interaction interface between human and gadget as simple as possible. And an ideal case - get rid of it completely. But as usual devil still presents in details. So in further your text you consider hierarchical relationship as result of affection of constant interface and developing of principle recognition for mid-air gesture... But in fact, as you wrote we have the interaction design as 30-th years progress in gesture recognition researches. But I did not see any highlight that over the last thirty years these interfaces (human-gadget) have also evolved substantially. Mouses obtain more resolution, touch-screens can detect more taps, cameras for mid-air gesture recognition get more dpi-resolution. So the question is this evolution as a factor should be taken into account or not? Could you add some words on this matter to your text?
Response 1: You are right that these developments should be taken into account. Technology and interaction design are interdependent. I added the corresponding content in lines 56-62 of the article. About the more detailed content I think it needs to be added as well. However, in view of the streamlined nature of the journal, additional content is planned to be added in our PhD thesis. If you have time and are interested, I will welcome your communication and guidance for further research. Here are the additions to the article :Technology and interaction design are interdependent. The development of mid-air gesture technology started with data gloves, followed by RGB cameras, radar, myoelectric sensors, 3d ToF and other technologies, due to the development of sensors and other hardware technologies, mid-air gesture recognition has improved greatly in terms of recognition types and recognition rates. Ideally, users can achieve human-computer interaction at any time through mid-air gestures, but the ideal state is not yet reached due to the limitations of the technology level.
Point 2: ISM acronym - I see it during the whole text more than couple times. I understand that you mean 'Interpretative structural modeling', but I did not see in text the definition for this acronym? Should it be there or not?
Response 2: You are right, I only considered the conciseness and easy comprehensibility of the expression and neglected to explain that it should be explained at the first abbreviation, which caused miscommunication. I have made changes in lines 70-71 of the article :Accordingly, interpretative structural modeling (ISM) theory was selected to study the influencing factors of gesture satisfaction.
Point 3: Lines 144 - 145: "The propor- 144 tion of male and female respondents was 47.43% and 52.58%". Let's add up these numbers: 47.43% + 52.58% = 100.01 % - it might be misprint in text?
Response 3: Thank you very much for your seriousness. This is an obvious mistake, the reason is that I misread the numbers, which led to reading the number 47.42% as 47.43%. I will be more careful in my subsequent writing and check all the numerical information. I made a correction to the figure in line 181 of the article （line 181）:The proportion of male and female respondents was 47.42% and 52.58%.
Point 4: Question to Results item: "The overall reliability and validity of the 30-item questionnaire were analyzed".
I have to ask - is it possible to give the readers a reference on data analyzed for this paper? It is usually welcomed when published data is put in the public domain so that readers can also check the published conclusions, if the data are not the subject of any secrecy.
As for the conclusions and conclusion of this article, they seem reasonable and unquestionable according to the logic of the narrative.
Therefore, I believe that the above deficiencies can easily be corrected, and the article itself can be printed in the near future.
Response 4: I personally would love to provide readers with a reference to the data analyzed in this paper, but it is still under wraps as I am currently designing a product that uses mid-air gesture interaction that is not yet available. I expect to place the published data in the public domain when the product is available in 2025. Also, my PhD thesis will add a lot of design and data on mid-air gesture satisfaction, which will be made public together at that time.
We sincerely hope that this revised manuscript has addressed all your comments and suggestions. We appreciated for reviewers' warm work earnestly, and hope that the correction will meet with approval. Once again, thank you very much for all your comments and suggestions.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear authors,
The new version of the article shows important improvements. It is important for the readers to know what kind of mid-air gestures have been tested in your work. But one question remains open still. In your study the users evaluated the efficiency of the mid-air gestures. The on only way, how you can evaluate this feature is to use mid-air gestures in order to accomplish some controlled predefined human-computer interaction related tasks, which should be the same for all participants in the study to get comparable answers. The tasks should be evaluated by the authors and then included in the mid-air gesture efficiency evaluation, as this is an important factor, that must not be neglected. Some part of the text in Figure 4 are obstructed by the square edges (Attractiveness, Friendliness, Intuitiveness). Please correct that.
Author Response
Thank you for taking the time to review my submission. I noticed your comments regarding the English language, so I have made revisions to the article to meet the requirements.
Point 1: The new version of the article shows important improvements. It is important for the readers to know what kind of mid-air gestures have been tested in your work. But one question remains open still. In your study the users evaluated the efficiency of the mid-air gestures. The on only way, how you can evaluate this feature is to use mid-air gestures in order to accomplish some controlled predefined human-computer interaction related tasks, which should be the same for all participants in the study to get comparable answers. The tasks should be evaluated by the authors and then included in the mid-air gesture efficiency evaluation, as this is an important factor, that must not be neglected.
Response 1: The questionnaire does not specify specific tasks, as this cannot be controlled. Furthermore, if specific tasks were assigned, it would limit users' answers to existing technology and products, making it difficult to obtain their objective opinions.
The reason for this lack of control is that the first modification included the addition of gesture postures, but even in existing products, the same gesture posture can have different functions. The efficiency referred to in the article is actually an evaluation of six variables: Easy to identify, Easy to trigger, Accuracy, Fluency, Fast recognition, and High success rate, which were combined into a factor through factor analysis. Therefore, it is an evaluation of these six variables. Users are already familiar with touch screen gestures on the iPhone and have experience with many external devices such as remote controls and game controllers. When using mid-air gestures, they will inevitably compare them to these experiences, and users already have expectations. Our goal is to uncover users' true experiences with mid-air gestures.Moreover, there are no specific values for the aforementioned six indicators in existing research, so there may be issues when designing experiments. For example, in terms of fluency: there should be no obvious sense of lag during gesture operation. However, it was found that this is not the case during the development of motion gesture methods in the company. If the cursor in the interface immediately follows every slight movement of the user's hand, the user may feel anxious. I believe this requires ongoing research.In subsequent research, I will continue to study relevant issues related to mid-air gestures.
However, I agree with your opinion. Therefore, in my doctoral thesis, I designed several gestures that conform to the conclusions of this thesis, and then compared my designed gestures and their interaction methods with existing ones to obtain relevant values such as efficiency and satisfaction. If you have time and are interested, I would greatly appreciate your guidance.
Point 2: Some part of the text in Figure 4 are obstructed by the square edges (Attractiveness, Friendliness, Intuitiveness). Please correct that.
Response 2: We have made modifications to Figure 4 to avoid the issue of obstruction and improve its readability.
Figure 4. Interpretation structural model of user satisfaction influencing factors for mid-air gestures.
Author Response File: Author Response.docx
