Dear Dr. Abugri,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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Please go through the comments by reviewers #2 and #3. Please ignore Reviewer #1's comments.

Regarding Reviewer #2's comment about the small sample of final papers and your presented conclusions, I have two suggestions - feel free to choose one, but if you want to do the minimum required then please go with option #1.

(1) Limiting and qualifying your conclusions based on the fact you have a very small sample without ability to conduct thematic analysis or inferential statistics. Related to this, I suggest adding a sub-section to your 'Discussion' section, titled 'Limitations', which will outline the limitations of your study.

(2) Expanding your final sample by relaxing some of your inclusion/exclusion criteria, which might change your research scope/objective/questions somewhat (don't go too far with this of course). The advantage of this approach is that you will be able to say more about your final sample of papers and support more of what you have to say, potentially with thematic analysis and perhaps even inferential statistics. In short, your contribution will be greater. Related to this, I suggest adding a sub-section to your 'Discussion' section, titled 'Contribution', which will outline the contributions of your study.

==============================

Please submit your revised manuscript by Jul 13 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
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If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Rea Lavi

Academic Editor

PLOS ONE

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1. When submitting your revision, we need you to address these additional requirements.-->--> -->-->Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at -->-->https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and -->-->https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf-->--> -->-->2. Please provide a complete Data Availability Statement in the submission form, ensuring you include all necessary access information or a reason for why you are unable to make your data freely accessible. If your research concerns only data provided within your submission, please write "All data are in the manuscript and/or supporting information files" as your Data Availability Statement.-->--> -->-->3. When completing the data availability statement of the submission form, you indicated that you will make your data available on acceptance. We strongly recommend all authors decide on a data sharing plan before acceptance, as the process can be lengthy and hold up publication timelines. Please note that, though access restrictions are acceptable now, your entire data will need to be made freely accessible if your manuscript is accepted for publication. This policy applies to all data except where public deposition would breach compliance with the protocol approved by your research ethics board. If you are unable to adhere to our open data policy, please kindly revise your statement to explain your reasoning and we will seek the editor's input on an exemption. Please be assured that, once you have provided your new statement, the assessment of your exemption will not hold up the peer review process.-->?>

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Partly

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2. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #1: I Don't Know

Reviewer #2: N/A

Reviewer #3: N/A

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3. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

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4. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1:  Providing a rationale discussion for the difference in results that was provided through such huge revision of such numbers of the study would have provided a new prospective for the paper other than it's provided version

Reviewer #2:  The article is well written and covers the objective well. The scoping review has followed standard procedure and has explained its findings well.

The few minor issues found are:

1. The full form of TBL is not explained.

2. Table 1 is out of view in PDF and only visible in downloaded word file. The formatting may need to be changed by authors or the editorial.

3. Few language issues were seen, eg. use of "cannot established".

Two major issues found are:

1. Flow chart looks a bit confusing. The second exclusion isn't given a reason.

2. References might need to be redone according to journal guidelines and definitely need to be seen one by one. There are some inconsistencies like all caps headings.

Reviewer #3:  PBL in undergraduate learning is an interesting and under-researched area, and I hope the authors will consider directions for a future iteration of this paper.

I have 3 concerns about this paper:

1. It isn’t clear to me why so few papers were judged to meet the criteria. As I mention below, I used the authors’ search terms on only Google Scholar (and not on the other databases they used) and found easily found a number of articles that fit their stated criteria, were in fact based on these criteria, and discussed them clearly. The selection methods need to be more carefully articulated so they are defensible, or possibly, the authors might consider returning to the search results.

2. The tiny sample of articles in this paper does not justify its conclusions. One article on first-year medical students can suggest a way to proceed, but in itself it is not definitive of anything. The article methods are, as the authors note, variable and include attitude studies, questionnaires, and perceptions. It is difficult to draw conclusions from self-report.

3. The use of the words trials, causation, and guaranteed indicates a need for rethinking the kind of literature they are examining, much of which, again, is self-report or perception-based. These more clinical words do not fit this territory.

Line by line comments:

ll. 30, 33: major conclusions drawn on the basis of a single study

l. 46: “lots of”: please indicate which strategies and arrive at a number

l. 47: “time immemorial” indicates back thousands of years

l. 54: citation does not fit the assertion

l. 61: Barrows said PBL was not a method and noted the wide variety of objectives

l. 68: augusted is not a word

l. 72: “monumental historical proportions” : avoid these vague assertions

l. 81: Organizational issue: this needs to be moved elsewhere. No link to previous paragraphs.

ll. 83-5: in Ghana or in general? Define “several curricula”

l. 90: suggest using Garrison (1992) and Newman et al (1995) in addition to Facione. They have metrics for analysis

l. 101-102: important to distinguish between self-report, which is notoriously unreliable, and assessment.

l. 105: Organization issue: this is a new topic

L. 115: TBL is distinct and its use here does not seem to serve a purpose

l. 130-31: is this clearly done later?

l. 163-64: Where was this presented?

l. 224-25: rich and poor settings only thematic trends?

l. 235-36: please identify the “rigorous process.” This is important because so few studies were identified, and it presents a blank space in the process. Why were so few identified? I conducted a search using only 1 set of the search terms in Google Scholar and found a substantial number of studies that met the criteria set in this paper.

l. 242: showcases: find better word.

l. 310-13: while on its own this statement seems defensible, the “heterogeneity in data collection… limits the generalizability of findings.” This is a chief weakness and undercuts the assertions that are made throughout the rest of the chapter. One way around this would be to discuss the articles in groups by author. However, even then, ll. 329-33 present a problem for making any claims in such a tiny study. The best that can be set is that the study, small as it is, suggests possible…..

ll. 365-66: same issue here with assertions based on extremely limited data

ll. 409-10: how is this clear?

ll. 424: where could this guidance come from?

ll. 432: Causation is not possible in these studies. PBL can enhance (as this piece points out on l. 455), or be an opportunity for learning.

ll. 437: Best to avoid the use of “trials,” usually limited to clinical studies.

l. 445: research gaps are not “filled up”

l. 447: no way to guarantee this.

Table 2: confusing; suggest adding columns or spaces to indicate that the same articles are categorized in multiple ways

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what does this mean? ). If published, this will include your full peer review and any attached files.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step.

Dear Dr. Abugri,

Please explain in more depth how and why the initial 20,789 papers were excluded (line 245).

"The studies were also extremely variable in design, sample size, and assessment tools, precluding synthesis and resulting in an inability to conduct thematic or inferential statistical analysis" (lines 285-287). If there is no ability to synthesize or analyze, then what can we learn from this effort? I would suggest either expanding your study scope and subsequently your search criteria to include more papers, or find a way to analyze the papers you did include qualitatively or thematically. For ideas, you can view the following, though there are other sources you can use:

Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative research in psychology, 3(2), 77-101.

Conducting such an analysis would require you to add to your introduction and return to those sources in the findings, making your paper richer and more insightful for readers.

Please submit your revised manuscript by Nov 06 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Rea Lavi

Academic Editor

PLOS ONE

Journal Requirements:

If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise.

Additional Editor Comments:

Reviewer #4:

Reviewer #5:

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

Reviewer #4: (No Response)

Reviewer #5: (No Response)

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2. Is the manuscript technically sound, and do the data support the conclusions??>

Reviewer #4: Partly

Reviewer #5: Partly

**********

3. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #4: N/A

Reviewer #5: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #4: Yes

Reviewer #5: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #4: Yes

Reviewer #5: Yes

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Reviewer #4: I acknowledge that this is an ambitious study mapping available evidence on PBL effects. However, I believe the manuscript is incomplete for the following reasons:

1) As the authors state in their limitations, "The overall number of studies that were included was small (n = 8), and only one of these focused specifically on first-year medical students, which lowers the generalizability and degree of analysis." Additionally, while "20,789 studies were excluded during this rigorous process," the specific reasons for exclusion at each stage remain unclear, making it difficult to assess the comprehensiveness of the review.

2) The authors acknowledge that "Most of the studies employed self-reported data that may yield subjective bias and undermine the validity of the findings" and used "cross-sectional designs, which made it harder to prove causative relationship or long-term effects." Furthermore, "The heterogeneity in data collection methods complicates direct comparisons across studies and limits the generalizability of findings." These methodological variations, particularly in measuring critical thinking skills, make it challenging to synthesize findings meaningfully.

3) While the authors state this is "a scoping review [that] maps available evidence," the abstract and conclusion make claims about PBL "may support the development of critical thinking and communication skills" and suggest "effectiveness," which goes beyond the stated objective of identifying "key themes and gaps in the literature."

4) Although "data description was summarized descriptively, using mainly thematic trends, and contextual comparison between resource-rich and poor settings," there is limited in-depth thematic analysis. The influence of "cultural backgrounds" and "diverse educational backgrounds" mentioned by the authors is not systematically examined. Consequently, while the authors aim to "optimize PBL's implementation," it remains unclear how medical educators can practically apply these findings in their specific contexts.

Reviewer #5: The manuscript explores the effects of problem-based learning (PBL) on undergraduate medical students' critical thinking and communication skills development using a scoping review framework proposed by Arksey and O'Malley. The set of skills selected is relevant to the medical education field.

Comments:

1. The title and abstract reflect the title of the study. Suggest to revise the keyword first year medical student, as it is also linked to medical education another one of your keyword.

2. The introduction provides a context for the study, however, it is long-winded. There seems to be a disconnect between the history of PBL and twenty-first-century education. It is suggested to bridge the gap by emphasizing the core problem faced by the medical students in general, leading to the first year undergraduate students. Is there a gap between the PBL offered in resource-rich and resource-poor areas, is this connected to the availability of technology?

3. The definition for critical thinking needs and communications skills need to be clarified as the text indicated other the expansion of variables such as critical thinking is represented by (analytical reasoning and problem-solving) and communication skills is represented by (teamwork and interpersonal communication)

4. The methodology was satisfactorily explained. The PRISMA flow diagram was included.

5. Table 1: Data extraction text is unclear.

6. For the results section, there happens to be a conflict on generic skills (Problem-solving and collaborative skills, when it was mentioned as generic skills are (Problem-solving and analytical reasoning) in the inclusion criteria.

7. The discussion was rather limited to outdated citations; to enhance the write-up by using current literature.

8. Conclusion sums up the study’s scope well.

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what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy

Reviewer #4: No

Reviewer #5: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step.

Dear Dr. Abugri,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Feb 21 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

• A letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Rea Lavi

Academic Editor

PLOS One

Journal Requirements:

1. If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise.

2. Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

Additional Editor Comments:

Dear Authors,

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Comments to the Author

Reviewer #5: All comments have been addressed

Reviewer #6: (No Response)

Reviewer #7: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions??>

Reviewer #5: Yes

Reviewer #6: No

Reviewer #7: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #5: Yes

Reviewer #6: N/A

Reviewer #7: N/A

**********

4. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #5: Yes

Reviewer #6: Yes

Reviewer #7: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #5: Yes

Reviewer #6: Yes

Reviewer #7: Yes

**********

Reviewer #5: (No Response)

Reviewer #6: thankyou for undertaking this review. Unfortunately I have two specific issues in relation to the methods which make the manuscript unsuitable for publication at this time. - specifically a comprehensive search strategy was not used therefore limiting studies identified

Firstly the authors have only used 'problem-based learning' in the search - this excludes 2 important synonyms : case-based learning and inquiry based learning

Secondly - ERIC was not included. While I would agree studies are likely to be in PubMed or Proquest, ERIC is the comprehensive education data base.

Reviewer #7: The authors have responded to reviewers' comments and have updated the manuscript. A few additional suggestions are below:

• Fix the in-text citation style. Remove the comma before numbering at the end of each sentence.

• Several citations are too old (For example, 1986). Please provide updated citations.

• Elaborate on resource-rich and resource-limited settings. What resources are needed for PBL? Give examples of PBL conducted in resource-rich and resource-limited settings.

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what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy

Reviewer #5: No

Reviewer #6: No

Reviewer #7: No

**********

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

To ensure your figures meet our technical requirements, please review our figure guidelines: https://journals.plos.org/plosone/s/figures

You may also use PLOS’s free figure tool, NAAS, to help you prepare publication quality figures: https://journals.plos.org/plosone/s/figures#loc-tools-for-figure-preparation.

NAAS will assess whether your figures meet our technical requirements by comparing each figure against our figure specifications.

The effects of problem-based learning (PBL) on undergraduate medical students' critical thinking and communication skills development. A scoping review across resource-rich and resource-limited settings (2015-2024).

PONE-D-25-14527R3

Dear Dr. Abugri,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

Rea Lavi

Academic Editor

PLOS One

Additional Editor Comments (optional):

Please shorten the title of the manuscript so that it does not take up more than two lines.

Please remove ".0" from section titles. Section titles should be, for example, "1. Introduction".