An Article is a substantial research study, with a complex story often involving several techniques or approaches. The main text (excluding abstract, Methods, references and figure legends) is typically no more than 4,000-4,500 words. The abstract is typically 150 words, unreferenced. Articles have up to 10 display items (figures and/or tables). An Introduction section is followed by sections headed Results, Discussion, Methods and Data Availability. Alternatively, authors may follow the IMRaD format and present the Methods prior to the Results section. The Results and Methods should be divided by topical subheadings; the Discussion may contain subheadings at the editors' discretion. As a guideline, Articles have around 60 references.
Articles include received and accepted dates. They may be accompanied by supplementary information. Articles are peer reviewed.
A Brief Communication reports a concise study of high quality and broad interest. Brief Communications begin with a brief unreferenced abstract (3 sentences, usually no more than 70 words). The main text is typically 1,000-1,500 words, including abstract, references and figure legends, and contains no headings. Brief Communications normally have no more than 2 display items, although this may be flexible at the discretion of the editor. Brief Communications include a Methods and Data Availability section. As a guideline, Brief Communications have around 20 references.
Brief Communications include received and accepted dates. They may be accompanied by supplementary information. Brief Communications are peer reviewed.
Comment is a very flexible format; Comments may be on policy, science and society or purely scientific issues. The main criteria are that they should be of immediate interest to a broad readership and should be written in an accessible, non-technical style. Their length is typically 1,000-2,000 words. Because the content is variable, the format is also flexible. Comments do not normally contain primary research data, although they may present 'sociological' data (funding trends, demographics, bibliographic data, etc.). References typically do not exceed 25.
Comments include received and accepted dates. Comments are typically peer reviewed.
Editorials are written by the senior editorial team of the journal, under the direction of the Editor-in-Chief. They are not typically peer reviewed, although they can be at the discretion of the editorial team, and are published with received and accepted dates.
Important scientific comments and clarifications on peer-reviewed articles published in npj Microgravity may be submitted as Matters Arising. The guidelines for Matters Arising are outlined here.
Meeting Reports are commissioned by the Editors and should include a substantive discussion and clear outputs from a scientific meeting or workshop that will be of broad interest to the wider community including those that could not attend. The text should not normally exceed 3,000 words. As a guideline, Meeting Reports allow up to 70 references.
Meeting Reports are always peer reviewed and include received and accepted dates.
Perspective is a format for scholarly reviews and discussions of the primary research literature that are too technical for a Commentary but do not meet the criteria for a Review—either because the scope is too narrow, or because the author is advocating a controversial position or a speculative hypothesis or discussing work primarily from one group. Two reviews advocating opposite sides in a research controversy are normally published as Perspectives. The text should not normally exceed 3,000 words. As a guideline, Perspectives allow up to 70 references.
Perspectives are always peer reviewed and include received and accepted dates.
A Review is an authoritative, balanced and scholarly survey of recent developments in a research field. The requirement for balance need not prevent authors from proposing a specific viewpoint, but if there are controversies in the field, the authors must treat them in an even-handed way. Reviews are normally 3,000-4,000 words, and illustrations are strongly encouraged. References are typically limited to 100, with exceptions possible. Citations should be selective. The scope of a Review should be broad enough that it is not dominated by the work of a single laboratory, and particularly not by the authors' own work.
Reviews include received and accepted dates. Reviews are always peer reviewed.