Reliability of search in systematic reviews: Towards a quality assessment framework for the automated-search strategy

Abstract Context The trust in systematic literature reviews (SLRs) to provide credible recommendations is critical for establishing evidence-based software engineering (EBSE) practice. The reliability of SLR as a method is not a given and largely depends on the rigor of the attempt to identify, appraise and aggregate evidence. Previous research, by comparing SLRs on the same topic, has identified search as one of the reasons for discrepancies in the included primary studies. This affects the reliability of an SLR, as the papers identified and included in it are likely to influence its conclusions. Objective We aim to propose a comprehensive evaluation checklist to assess the reliability of an automated-search strategy used in an SLR. Method Using a literature review, we identified guidelines for designing and reporting automated-search as a primary search strategy. Using the aggregated design, reporting and evaluation guidelines, we formulated a comprehensive evaluation checklist. The value of this checklist was demonstrated by assessing the reliability of search in 27 recent SLRs. Results Using the proposed evaluation checklist, several additional issues (not captured by the current evaluation checklist) related to the reliability of search in recent SLRs were identified. These issues severely limit the coverage of literature by the search and also the possibility to replicate it. Conclusion Instead of solely relying on expensive replications to assess the reliability of SLRs, this work provides means to objectively assess the likely reliability of a search-strategy used in an SLR. It highlights the often-assumed aspect of repeatability of search when using automated-search. Furthermore, by explicitly considering repeatability and consistency as sub-characteristics of a reliable search, it provides a more comprehensive evaluation checklist than the ones currently used in EBSE.