Original Research

Original Research articles report on primary and unpublished studies. Original Research may also encompass confirming studies and disconfirming results which allow hypothesis elimination, reformulation and/or report on the non-reproducibility of previously published results. Original Research articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish an Original Research article. Original Research articles should have the following format: 1) Abstract, 2) Introduction, 3) Materials and Methods, 4) Results, 5) Discussion.

Systematic Review

Systematic Review articles present a synthesis of previous research, and use clearly defined methods to identify, categorize, analyze and report aggregated evidence on a specific topic. Included in this article type are meta-syntheses, meta-analyses, mapping reviews, scoping reviews, systematic reviews, and systematic reviews with a meta-analysis. Systematic Review articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Systematic Review article. Systematic Reviews should: clearly define the research question in terms of population, interventions, comparators, outcomes and study designs (PICOS), and state which reporting guidelines were used in the study. For design and reporting, systematic reviews must conform to the reporting guidelines (e.g., PRISMA, Cochrane, Campbell), and include the PRISMA flow diagram http://prisma-statement.org/prismastatement/flowdiagram.aspx (if applicable), as well as funding information (if no specific funding to carry out the research, please state so). Systematic Reviews should have the following format: 1) Abstract, 2) Introduction, 3) Methods (including study design; participants; interventions; comparators; systematic review protocol; search strategy; data sources; study sections and data extraction; data analysis), 4) Results (including a flow diagram of the studies retrieved for the review; study selection and characteristics; synthesized findings; assessment of risk of bias), 5) Discussion (including summary of main findings; limitations; conclusions). Systematic Reviews must not include unpublished material (unpublished/original data, submitted manuscripts, or personal communications) and may be rejected in review or reclassified, at a significant delay, if found to include such content.

Methods

Methods articles present either a new or established method, protocol, or technique that is of significant interest in the field. Methods articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Methods article. Method articles should have the following format: 1) Abstract, 2) Introduction (outlining the protocol and its possible applications), 3) Materials and Equipment (including a list of reagents/ materials and/or equipment required; formulation of any solutions where applicable), 4) Methods (including objectives and validation of the method; step-by-step procedures; timing of each step or related series of steps; pause points; example(s) of application and effectiveness; details of precision/ accuracy and limits of detection or quantification, where applicable) , 5) (Anticipated) Results (describing and illustrating with figures, where possible, the expected outcome of the protocol; advantages, limitations, possible pitfalls and artifacts and any troubleshooting measures to counteract them), 6) Discussion. Any analytical methods applied to the data generated by the protocol must be referenced or described. Results must be replicable.

Review

Review articles cover topics that have seen significant development or progress in recent years, with comprehensive depth and a balanced perspective. Reviews should present a complete overview of the state of the art (and should not merely summarize the literature), as well as discuss the following: 1) Different schools of thought or controversies, 2) Fundamental concepts, issues, and problems, 3) Current research gaps, 4) Potential developments in the field. Review articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Review article. Review articles should have the following format: 1) Abstract, 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion. Review articles must not include unpublished material (unpublished/original data, submitted manuscripts, or personal communications) and may be rejected in review or reclassified, at a significant delay, if found to include such content.

Mini Review

Mini Review articles cover focused aspects of a current area of investigation and its recent developments. They offer a succinct and clear summary of the topic, allowing readers to get up-to-date on new developments and/or emerging concepts, as well as discuss the following: 1) Different schools of thought or controversies, 2) Current research gaps, 3) Potential future developments in the field. Mini Reviews articles are peer-reviewed, have a maximum word count of 3,000 and may contain no more than 2 Figures/Tables. Authors are required to pay a fee (B-type article) to publish a Mini Review article. Mini Review articles should have the following format: 1) Abstract, 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion. Mini Review articles must not include unpublished material (unpublished/original data, submitted manuscripts, or personal communications) and may be rejected or reclassified, at a significant delay, if found to include such content.

Policy and Practice Reviews

Policy & Practice Reviews provide a comprehensive coverage and balanced overview of current and relevant topics related to policy, regulations, and guidelines that may be coming from academia, relevant societies, regulatory bodies, industries and others. In contrast to Policy Briefs, this article type provides authors with more space to elaborate on policies and/or guidelines. Policy & Practice Reviews are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Policy & Practice Review. Policy & Practice Reviews should have the following format: 1) Abstract, 2) Introduction, 3) Sections on assessment of policy/guidelines options and implications, 4) Actionable Recommendations, 5) Discussion.

Hypothesis and Theory

Hypothesis and Theory articles present a novel argument, interpretation or model intended to introduce a new hypothesis or theory. They should provide the following: 1) New interpretation of recent data or findings in a specific area of investigation, 2) Accurate presentation of previously posed hypotheses or theories, 3) Hypothesis presented should be testable in the framework of current knowledge, 4) May include original data as well as personal insights and opinions. Hypothesis and Theory articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Hypothesis and Theory article. Hypothesis and Theory articles should have the following format: 1) Abstract, 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion.

Perspective

Perspective articles present a viewpoint on a specific area of investigation. They should provide the following: 1) Discuss current advances and future directions, 2) Clear presentation of the authors’ perspective, 3) Accurate presentation and citations of other authors’ work, 4) May include original data as well as personal insights and opinions. Perspective articles are peer-reviewed, have a maximum word count of 3,000 and may contain no more than 2 Figures/Tables. Authors are required to pay a fee (B-type article) to publish a Perspective article. Perspective articles should have the following format: 1) Abstract, 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion.

Conceptual Analysis

Conceptual Analysis articles explore the concepts and issues that define a field. They should examine the constituent elements of each concept, and the connections between them. Conceptual Analysis articles must not include unpublished material (unpublished/original data, submitted manuscripts, or personal communications) and may be rejected or reclassified, at a significant delay, if found to include such content. Instead, Conceptual Analysis articles should extend current knowledge by presenting a novel argument, interpretation, model, or critique. Conceptual Analysis articles are peer-reviewed, have a maximum word count of 8,000 words and may contain no more than 10 Figures/Tables. Authors are required to pay a fee (B-type article) to publish a Conceptual Analysis article. Any inclusion of verbatim text must be contained in quotation marks and clearly reference the original source. Conceptual Analysis articles should have the following format: 1) Abstract, 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion.

Classification

Classification articles include a brief commentary and a set of classifications that have previously received scientific scrutiny by expert groups of investigators so as to bring definition and order to nomenclature. As such, Classification Articles will necessarily change from time to time, and be republished, as new information accrues. Classification articles are peer-reviewed, have a maximum word count of 2,000 and may contain no more than 15 Table/Figures. Authors are required to pay a fee (A-type article) to publish a Classification Article. Classification articles should have the following format: 1) Abstract, 2) Introduction (brief commentary) 3) Set of Classifications 4) Discussion.

Policy Brief

Policy Briefs articles are short reports that provide a practical and evidence-based evaluation of policy-related issues. This article type also provides policy options and actionable recommendations which allows it to be used as a decision-making tool. Policy Briefs articles are peer-reviewed, have a maximum word count of 3,000 and may contain no more than 5 Tables/Figures. Authors are required to pay a fee (B-type article) to publish a Policy Brief article. Policy Brief articles should have the following format: 1) Abstract (up to 125 words in a bullet point format), 2) Introduction, 3) Sections on Policy Options and Implications, 4) Actionable Recommendations, 5) Conclusions.

Brief Research Report

Brief Research Report articles present original research and/or preliminary findings in a more succinct way, and with fewer details, than Original Research articles. Additionally, in line with the Frontiers ethos of publishing scientifically-sound discoveries, Brief Research Reports also encourage submission of negative results and may report on the non-reproducibility of previously published results. Brief Research Reports articles are peer-reviewed, have a maximum word count of 4,000 and may contain no more than 4 Figures/Tables. Authors are required to pay a fee (B-type article) to publish a Brief Research Report. Brief Research Report articles should have the following format: 1) Abstract, 2) Introduction, 3) Method, 4) Results, 5) Discussion. Supplementary material may be included with Brief Research Reports.

General Commentary

General Commentary articles provide critical comments on a previous publication at Frontiers. Authors wishing to submit commentaries on articles published outside of Frontiers are encouraged to reformat and submit them as an Opinion type. General Commentary articles are peer-reviewed, have a maximum word count of 1,000 words and may contain no more than 1 Figure/Table. They should not contain unpublished or original data. General Commentary articles must be submitted for consideration to the same Journal and Specialty as the original article. Authors are required to pay a fee (C-type article) to publish a General Commentary article. General Commentary articles should have the following format: 1) Title: “Commentary: Title of the original article” (mandatory), 2) Introduction, 3) Subsections relevant for the subject, 4) Discussion. At the beginning of your General Commentary, please provide the complete citation of the article being commented on.

Opinion

Opinion articles allow authors to contribute viewpoints on the interpretation of recent findings in any research area, value of the methods used, as well as weaknesses and strengths of scientific hypotheses. They should abide to the following guidelines: not contain unpublished or original data, be supported by evidence, be fully referenced, encourage constructive discussion, refrain from emotionally-charged argumentation. Opinion articles are peer-reviewed and have a maximum word count of 2,000 and may contain no more than 1 Figure/Table. Authors are required to pay a fee (C-type article) to publish an Opinion article. Opinion articles should have the following format: 1) Introduction, 2) Subsections relevant for the subject, 3) Discussion.

Correction

Corrigendum/Addendum: should authors notice errors that affect the scholarly record or the integrity of the paper, authors are encouraged to submit a correction online. The correction must detail the reason(s) for the error(s) and include only the elements (e.g. sections, sentence, figure) of the manuscript being revised or corrected. All authors of the original paper need to agree to the request for changes. The contribution to the field statement should be used to clearly state the reason for the Correction. Depending on the extent of the correction required, corrections may require peer review. Authors are informed that requests for changes beyond that described here may not be accepted for publication.

Erratum: should authors notice differences between their approved galley proofs and the final published article, thus leading to errors that affect the scholarly record or the integrity of the paper, authors are encouraged to submit a request for erratum to the Frontiers Production Office (production.office@frontiersin.org), clearly specifying the error and the correct information.

Editorial

Editorials are submitted exclusively by the host editor(s) of a Frontiers Research Topic, to convey to the reader the aims and objectives of the research that pertains to the topic, as well as placing it in a broader context. The Editorial should present the contributing articles of the Research Topic but should not be a mere table of contents. As the final contributing article to the Research Topic, Editorials should be submitted once all expected articles have been accepted and published. Editorials should not include unpublished or original data and the inclusion of references is strongly encouraged. Editorial articles may contain 1 Figure and have a word count of 1,000 for Topics with 5-10 articles. The word limit can be increased for each additional article in the Topic, up to a maximum of 5,000 words for 50 articles or more. Topic editors are not required to pay a fee to publish an Editorial article. Submissions are required to have the title Editorial: "Title of Research Topic".

Study Protocol

Study Protocol articles document the design of prospective research and it is intended to facilitate dissemination of ongoing studies and promote transparency. Study Protocol articles are peer-reviewed, have a maximum word count of 12,000 and may include up to 15 Figures/Tables. Authors are required to pay a fee (A-type article) to publish a Study Protocol article. Study Protocol articles should have the following format: 1) Abstract (please include the clinical trial registry number for clinical studies), 2) Introduction, 3) Methods and Analysis (including design; selection/treatment of subjects; interventional methods; data analysis), 4) Discussion, 5) Ethics and Dissemination. For clinical studies, registration in a public clinical trial registry is mandatory prior to the submission of the manuscript and the authors are strongly encouraged to follow the SPIRIT guidelines (http://www.spirit-statement.org/) and checklist. Study Protocols are not considered if other articles relating to the study are already published or in review, if it reports any research data from the study, or for any pilot or feasibility study.