Influences on single-use and reusable cup use: a multidisciplinary mixed-methods approach to designing interventions reducing plastic waste

Thank you very much for addressing the comments I have provided. The quality of work has really improved and is now more clear and comprehensive. The additions to literature review and clarification of aims has really helped the understanding of importance of this framework and gives a clearer idea of what will be addressed.

I just noticed a couple of minor typos:

1. p 8, first paragraph, last sentence. The comma after "and" should probably be before "and".

2. p 13, under "case study description", the following sentence seems to have a mistake: "Since previous efforts to eradicate single-use coffee cups across the campus had been of limited effectiveness, the university aims to develop of an intervention informed by behavioural science".

Good luck with the implementation of this project!

The paper has been deeply improved by the use of new explanatory tables. However, I suggest a few further minor revisions and improvements before being accepted.

First, I’m wondering if, in order to improve the narrative and to help the readers, it is possible to modify the central part of the methodology (e.g. pg. 11-12) from future (e.g. To identify the various capability, opportunity and motivation related influences on single-use and reusable cup use, we will compute the mean scale scores ) to suggestion/statement (e.g. To identify the various capability, opportunity and motivation related influences on single-use and reusable cup use, the mean scale scores may be computed … ).

Second, since it is a design method proposal, I suggest adding a simple flowchart in the methodology section in order to summarize the various steps to be implemented for future researches.

Other minor comments:

• Pg. 4 declare BCW acronym first time in the text as well.
• Fig. 4, please declare if it is elaborated by the authors or add the reference.

The article addresses an imporant and under-explored issue of eradicating single-use cups using theoretical framework of behaviour change. As there is not much literature on this particular behaviour, and none - to my knowledge - of the application of the Behaviour Change Wheel theory to it, it has a potential to contribute to the field significantly. At this stage, this is a protocol of a mixed-methods study.

It would be beneficial to expand the literature review to elaborate more on two areas:

a) Include the research on previous efforts made to increase the use of reusable cups, for instance, the two behaviour change interventions, published recently:

- Poortinga, W., & Whitaker, L. (2018). Promoting the use of reusable coffee cups through environmental messaging, the provision of alternatives and financial incentives. Sustainability , 10 (3), 873.

- Novoradovskaya, E., Mullan, B., Hasking, P., & Uren, H. V. (2021). My cup of tea: Behaviour change intervention to promote use of reusable hot drink cups. Journal of Cleaner Production , 284 , 124675.

b) Elaborate on the theories referred to in the introduction, COM-B, TDF and BCW. It is important to reflect why these three models were chosen, how they demonstrated effectiveness previously, and provide some examples of specific components of the frameworks, not just descriptions. It would also be beneficial to elaborate further on how COM-B and TDF line up with BCW, as it is not particularly clear.

It is also important to clarify the aims of the research. For example, in "What are the influences on single-use and reusable cup use?" it is unclear as to what exactly 'influences' refer to. There is potnetial to formulate hypotheses for the survey part of the findings.

In Methods I was wondering about details of the conducted power analysis, e.g., for which statistical test was it conducted?

Regarding the Survey : it may be needed to insert another question as the very first one or as an inclusion criterion for the study, whether the participant consumes takeaway hot drinks at all. There is a risk to end up with skewed data if those who do not drink takeaway hot drinks would be completing the survey and it is not controlled for.

In the Procedure section it is unclear how exactly the participants would be selected: randomly or using a certain strategy?

I am very excited to read this paper once the data can be obtained!

The topic is up to date but, in my opinion, the way the paper is written is not adequate for a scientific publication.

Interesting premises, and introduction. The literature presented and the framework could be really interesting to analyze pro-environmental behavior but not as it is presented.

I strongly suggest following a classic structure:

1) Introduction: frame of the general problem, literature gap, research question, and novelty

1.1) Literature review

2) Methodology: design, method, case study description.

3) Results and discussion

4) Conclusion

The wrong structure generates a lack of clarity in the presentation and in the general reading.

At the actual stage, the authors attempted to present a methodology instead of results, but without really adding novelty since the questions of the survey are quite trivial and partially bias in the actual form. Moreover, the framework presented in the first part is hard to connect with the survey. I suggest mapping some aspects presented in the framework with the current proposed survey. Finally, within the paper, it is not necessary to repeat several times that the survey was interrupted by the COVID-19, since the aim should be to present a method rather than results and for this purpose the COVID-19 has no impact.

Some minor comments:

1) pg. 2: "Life cycle assessments have shown reusable cups to be a more sustainable alternative to single-use cups, if used over 72 times (6)." It is not always true. It depends on which impact category is considered.

2) pg. 6: Aims section. I suggest to move in the introduction before the literature review

3) pg. 6: "Data collection ...." move it into methodology section

4) pg.7: "This will be a mixed-methods study". Citation needed