Detecting Mind-Wandering from Eye Movement and Oculomotor Data during Learning Video Lecture
Round 1
Reviewer 1 Report
The authors propose an interesting and important issue. This work uses the self-caught method to capture the mind-wandering timing of pre-service while learning from video lectures. Experiment assumptions are OK. However, the quality of figures 1, 3, and 4 should be improved. Please remove the word grammar and spelling check in figures.
Figure 3: resting ---> Resting
Author Response
Response1: I replaced figure 1 with a clearer and more objective graph picture. Because the previous picture showed amplitude of evoked response as too simplistic and unrealistic(page 3, line 107).
Response2: I removed the word grammar and spelling check from figure 3, 4 and made a figure again to show a clear figure(page 5, line 181, 183)
Response3: I replaced 'resting' with 'Rest'
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This is an interesting study that adds to knowledge in this particular area. The literature review presented gives sufficient background and context to frame the present study. The methodology employed is well described and the data collection appears to have been carried out effectively. Overall, the article demonstrates that the authors achieved their aim to identify useful mind-wandering markers.
One concern I had was around ethical approval for the study. There is no mention of this study having been granted ethical approval by an institutional review board. Was this done? If so, it should be indicated in the text. If ethical approval was not received, I don't think this should stop the article from being published. However, as the study found that some participants experience psychological discomfort as a result of mind-wandering, and the fact that this may be exacerbated by participation in a study such as this, I feel that it is important that ethical approval is sought by the research team for all future studies. This is particularly important when participants are being interviewed about their experiences.
I would find it helpful if it were more clearly indicated in the results tables what the numbers are e.g. in Table 1, I think that the fixation durations are reported in milliseconds - could this be indicated either in the table caption, or in the heading for the table? This could also be done for the other results tables where appropriate (i.e. it's not needed in Table 2, as it is clear that this is a 0 to 1 scale).
p.5 line 168 Were the participants interview immediately after watching the lecture? Please state if so.
Beyond that, I don't see any necessity for more significant changes to be made.
Comments for author File: Comments.pdf
Author Response
Response1: This study was already approved by the Bioethics Review Board of the Korea National University of Education before conducting the experiment(project identification code:KNUE-2019-H-00225, date of approval: August 29, 2019).
We fully explained the purpose of the study, the principles of measuring oculomotor data and eye movement, and the potential benefits and risks of participating in the study to the participants and confirmed whether they were willing to participate in the experiment voluntarily. All participants expressed their willingness to participate in the study voluntarily, as I have indicated this in lines 138-144 on page 4.
Response2: In the table heading of the results tables, I have clearly explained the numbers. In table 1, I have indicated milliseconds(line 225 on page 6), and in table 3, I have presented the units of amplitude and speed as amplitude in pixels and velocity in pixels per second, respectively(line 252 on page 7). Finally, the size of the pupil is indicated in millimeter units in table 5(line 275 on page 8).
Response3: After watching a video lecture, the paticipants were immediately interviewed about their MW experience while watching the eye-tracking video and the time point of MW reporting through Tobii pro lab; I have indicated this lines 178-180 on page 5.
