Acceptance of Automated Shuttles—Application and Extension of the UTAUT-2 Model to Wizard-of-Oz Automated Driving in Real-Life Traffic
Round 1
Reviewer 1 Report
Exciting and well-done research. Of course, the sample is tiny with all its problems in statistical treatment. Fair enough that you state this problem in the limitation section. However, the conclusions derived are on a fragile statistical basis. But, for me, this is not crucial as the actual effort of the study is the setup, and I am sure, in the future, a larger sample and a more sophisticated car (a Volkswagen Passat would immediately be suspicious to me as SEA Level 4 :-) )
Just two minor suggestions: It would be interesting for readers unfamiliar with UTAUT and TAM to describe the differences resp.the development from TAM to UTAUT and its pros and cons. Just a few sentences to ad. A break by moderators (age, sex, education, culture, etc.) would be fascinating in the follow-up study.
Great job guys.
Author Response
Thank you for your positive evaluation of our manuscript. We added improvements to the manuscript in the track changes mode. Please find the replies to your suggestions below:
Suggestion 1: It would be interesting for readers unfamiliar with UTAUT and TAM to describe the differences resp.the development from TAM to UTAUT and its pros and cons. Just a few sentences to ad.
Our reply: Thanks for this hint, we rephrased the paragraph regarding the development of the UTAUT, such that it now includes a brief description of the development from TAM to UTAUT (see l. 44 ff).
Suggestion 2: A break by moderators (age, sex, education, culture, etc.) would be fascinating in the follow-up study.
Our reply: We added one sentence regarding the homogeneity of the cultural background and age and a sentence to motivate further research with the abovementioned personal characteristics to the Discussion (see l. 596ff. and 604ff.).
Reviewer 2 Report
This paper reflects research into passenger perceptions of AV's using a WoO methodology. There have of course, been many of these. The central flaw is, despite driver screening, the knowledge of participants that they are in a vehicle driven by a human being. These and other shortcomings such as gender imbalance and the already sympathetic opinion of participants to AV' is addressed, although I couldn't find anything that responded to age which would have been helpful. I'm not from a statistics based background so I cannot vouch for the veracity of the modelling. Taken at face value the sample number of 35 would appear to give some semblance reliability. I probably would have preferred to see something of the set up in the car and the questions earlier in the piece rather than as an appendix.
Author Response
Thank you for your positive evaluation of our manuscript. We added improvements to the manuscript in the track changes mode. Please find the replies to your suggestions below:
Issue 1: The central flaw is, despite driver screening, the knowledge of participants that they are in a vehicle driven by a human being.
Our reply: We agree with the reviewer that a Wizard-Of-Method with a safety-driver present could foster that participants realize that the car is actually driven by a human being. However, in the instruction participants were told that the car was automated (l. 292 ff.), we installed a partition in the car (see newly added Figure 2, l. 294ff.)) and excluded the four participants from further analyses, who could not immerse with the situation (see l. 245ff.). To add, before the ride we showed a real video to the participants in which the car drove automated for a part of the used route in real traffic (see l. 298ff). Hence, we argue that the participants experienced the rides as if they were sitting in an automated vehicle.
Issue 2: These and other shortcomings such as gender imbalance and the already sympathetic opinion of participants to AV' is addressed, although I couldn't find anything that responded to age which would have been helpful.
Our reply: We agree with the reviewer that age could have an influence and added this to the discussion (see l. 604ff).
Issue 3: I probably would have preferred to see something of the set up in the car and the questions earlier in the piece rather than as an appendix.
Our reply: That is good idea. We added a Figure showing the interior of the vehicle with the partition (Figure 2) and moved the table with the questions from the appendix to the body text (Table 1).
Round 2
Reviewer 2 Report
The amended manuscript addresses my concerns satisfactorily.
