This study addresses an emerging topic for medical education research - the use of electronic messaging tools to expand learning "beyond the classroom". The research question is well framed by the introduction, but the methods section needs considerable revision to make this research potentially reproducible and explain how the authors developed the content themes for discussion.

Title The title is descriptive, but provides no insight as to what type of study this is. Consider changing title to indicate that this is a descriptive and thematic evaluation of the content of WhatsApp messages. An indication this study was done in the context of problem based learning groups may also be useful.

Abstract The abstract is organized, but lacks detail of how the thematic analysis was conducted. Adding this information to the abstract would be useful. The research question is stated in the abstract.

Introduction/Background The introduction is broad and clearly outlines limitations of current knowledge and frames the research question clearly.

Methods Subject recruitment and ethical approval are clearly outlined. Some description of the institution at which the study was conducted may be helpful to readers - size, location (urban, rural, underserved), medical student class size.

Statistical analysis is nearly non-existent, simply reporting counts of messages and any media shared within the messenger app (images, web page links). Consider adding detailed analysis on a per question basis - how many responses does an average question/comment generate. Are discussions primarily faculty led?

How the qualitative analysis was performed is not discussed at all (theme organization, information from the interviews).

Improvements in the analysis section are important to make this research accessible and reproducible.

Results Counts for the number of participants, messages, and other content shared within WhatsApp are described.

Thematic examples are included, but how these themes were identified is not clear. Providing clarity as to how the messages were classified into themes would be helpful for anyone wishing to replicate this project or better understand how this intervention may have influenced the themes.

Discussion The discussion evaluates the results in the context of the current knowledge base. The importance of the results are not overstated. The limitations of the study were adequately discussed.

Conclusions are founded on the results and discussion.