A literature review should represent the relevant state of knowledge, not simply maximize the percentage of recent citations. Recent research matters, but older foundational and still-relevant studies may be equally necessary.
Read Guide →
A major review can give you a strong starting point, but its publication date does not tell you where its evidence ends. Find its last search date, understand how it searched, then systematically retrieve the research that appeared afterward.
Read Guide →
Database alerts rerun a saved search against newly added records and notify you when something matches. The useful ones come from searches precise enough to catch important new research without flooding you with irrelevant results.
Read Guide →
Citation alerts and keyword alerts monitor different signals. Citation alerts follow new work connected to a known paper, while keyword alerts look for new records matching a topic, so the right choice depends on what you want to keep watching.
Read Guide →
Keeping up with a research field does not mean reading every paper it produces. A sustainable system monitors several useful signals, screens new research quickly, and reserves close reading for work that could actually change what you know or do.
Read Guide →
A preprint can give you early access to important research, but being new does not make it important or reliable. Evaluate its relevance, methods, evidence, transparency, version history, and publication status before deciding how much attention it deserves.
Read Guide →
Sometimes the most recent evidence is available only as a preprint or another research output that has not completed peer review. You do not necessarily need to ignore it, but its preliminary status should affect how you evaluate, describe, cite, and rely on it.
Read Guide →
Grey literature includes research and other evidence produced outside conventional academic and commercial publishing. Learn what counts as grey literature and when searching for it can materially improve a literature review.
Read Guide →
Ignoring grey literature can leave a review with a systematically incomplete evidence base, especially when the availability of research depends on its results. The problem is not simply missing studies, but whether the evidence you can find differs from the evidence you cannot.
Read Guide →
Theses, dissertations, reports, and working papers are scattered across repositories, specialist databases, organizational websites, and search engines. Learn where to search and how to find documents that conventional journal databases may miss.
Read Guide →
Conference abstracts can reveal relevant studies before or without full publication, but their limited reporting makes them difficult to evaluate. Whether to include them depends on your review question, eligibility criteria, and intended use of the evidence.
Read Guide →
A conference abstract with no identifiable full paper should not simply disappear from your review. Trace the study carefully, seek additional information where appropriate, and decide what the abstract can support based on your review criteria and the information actually available.
Read Guide →
Government and institutional reports can contain valuable research evidence, including surveys, evaluations, administrative analyses, and technical studies. Their authority as documents, however, should not be confused with the methodological strength of the evidence they contain.
Read Guide →
A report does not become unreliable simply because it was never peer reviewed, but you cannot assume that someone else has checked it for you. Evaluate its provenance, methods, data, transparency, potential bias, and the strength of the claims it actually supports.
Read Guide →
Preprints can provide timely access to research before journal peer review, particularly in rapidly developing fields. Whether you should include them depends on your review purpose, eligibility criteria, and how carefully you manage their provisional and versioned status.
Read Guide →
When a preprint has subsequently become a peer-reviewed journal article, the journal version will usually be the appropriate source to cite. But the preprint should not automatically disappear when it contains unique information or differs meaningfully from the published paper.
Read Guide →
When a preprint and its published paper report different results, do not automatically discard one version or assume peer review explains the change. Compare the study versions systematically to determine what changed, why it matters, and which result should inform your interpretation.
Read Guide →
Studies can exist long before, or without ever becoming, journal articles. Learn how to trace unpublished and ongoing research through registries, conference records, repositories, study authors, sponsors, and other sources.
Read Guide →
Publication bias occurs when whether research becomes publicly available is influenced by its findings. The result can be a published literature that looks more positive, consistent, or convincing than the underlying body of research actually is.
Read Guide →
The file drawer problem occurs when completed research, particularly studies with null, non-significant, or otherwise unremarkable findings, remains undisclosed. When those hidden studies differ systematically from published research, the visible literature can give a misleading impression of the evidence.
Read Guide →
Searching for unpublished research can reduce the risk of missing important evidence, but it can also require substantial time for uncertain return. The right level of effort depends on your review question, the risk of selective publication, the likely location of missing studies, and whether finding them could realistically change your conclusions.
Read Guide →
A publisher paywall does not necessarily mean the paper is inaccessible or that you need to pay for it yourself. Several legitimate routes may provide the same paper through your library, an open-access copy, a repository, interlibrary loan, or the author.
Read Guide →
A paywalled journal article may have a legitimate open version elsewhere. Learn where to search, how to recognize different manuscript versions, and how to verify that the copy you find is the paper you actually need.
Read Guide →
An accepted manuscript has passed peer review but is not necessarily identical to the final published article. For many reading purposes it may contain the research you need, but post-acceptance changes, corrections, and citation details can sometimes make the version of record important.
Read Guide →
If you cannot access a research paper, contacting the author is a legitimate option and may result in a copy or an authorized access link. Learn whom to contact, how to make the request, and why the version an author can share may depend on publisher policies and publication rights.
Read Guide →