An automated approach to identifying search terms for systematic reviews using keyword co‐occurrence networks

Abstract

Systematic review, meta‐analysis and other forms of evidence synthesis are critical to strengthen the evidence base concerning conservation issues and to answer ecological and evolutionary questions. Synthesis lags behind the pace of scientific publishing, however, due to time and resource costs which partial automation of evidence synthesis tasks could reduce. Additionally, current methods of retrieving evidence for synthesis are susceptible to bias towards studies with which researchers are familiar. In fields that lack standardized terminology encoded in an ontology, including ecology and evolution, research teams can unintentionally exclude articles from the review by omitting synonymous phrases in their search terms. To combat these problems, we developed a quick, objective, reproducible method for generating search strategies that uses text mining and keyword co‐occurrence networks to identify the most important terms for a review. The method reduces bias in search strategy development because it does not rely on a predetermined set of articles and can improve search recall by identifying synonymous terms that research teams might otherwise omit. When tested against the search strategies used in published environmental systematic reviews, our method performs as well as the published searches and retrieves gold‐standard hits that replicated versions of the original searches do not. Because the method is quasi‐automated, the amount of time required to develop a search strategy, conduct searches, and assemble results is reduced from approximately 17–34 hr to under 2 hr. To facilitate use of the method for environmental evidence synthesis, we implemented the method in the R package litsearchr, which also contains a suite of functions to improve efficiency of systematic reviews by automatically deduplicating and assembling results from separate databases.

revtools: An R package to support article screening for evidence synthesis

“…Instead, the features provided by revtools are likely to be particularly powerful when used in combination with those of related packages. Currently, for example, it is possible to plan a search strategy with litsearchr 35 ; screen your articles with revtools; download articles using fulltext 36 ; analyze the resulting data in metafor 37 or one of the many other meta-analysis packages available in R 9 ; and present a database of study results using EviAtlas 38 . While this is encouraging, many stages of the systematic review workflow remain unsupported within R, with data extraction being a key gap.…”

revtools: An R package to support article screening for evidence synthesis

“…Instead, the features provided by revtools are likely to be particularly powerful when used in combination with those of related packages. Currently, for example, it is possible to plan a search strategy with litsearchr 35 ; screen your articles with revtools; download articles using fulltext 36 ; analyze the resulting data in metafor 37 or one of the many other meta-analysis packages available in R 9 ; and present a database of study results using EviAtlas 38 . While this is encouraging, many stages of the systematic review workflow remain unsupported within R, with data extraction being a key gap.…”

What evidence exists on conservation actions to conserve insects? A protocol for a systematic map of literature reviews

“…We will target grey literature by searching across Google Scholar, DART-Europe E-theses, ProQuest Dissertations & Theses A&I, the Networked Digital Library of Theses and Dissertations Global ETD Search, and OpenThesis. We will use litsearchr [63,64] to search NDLTD Global ETD Search and OpenThesis with the full search string and will use simplified searches (see Table 1) for thesis databases that do not have the capacity to support the full search string. We will not search for grey literature on individual organisational websites, due to resource constraints, but also because relevant literature reviews are highly unlikely to be found here and not elsewhere.…”

“…Where results cannot be saved as a csv file, they will be downloaded using either Publish or Perish (www. harzi ng.com), the Grey Literature Search Recorder app (https ://www.eshac katho n.org/softw are/grey-lit-repor ter.html), litsearchr [63,64], or custom functions in R to scrape records into a.bib or.ris format where possible. Otherwise, they will be screened in place (i.e.…”