Data Richness and Thickness Assessment Tool for Primary Qualitative Research Studies

Data richness and thickness are among several criteria that can be taken into consideration when sampling studies for inclusion for qualitative evidence syntheses (QES). The data richness and thickness assessment tool can ensure that selected studies align with the methodological needs of the selected synthesis approach. This tool was developed in a Cochrane context by methodologists in the Cochrane Qualitative and Implementation Methods Group and authors using an evidence-based approach. 

The aim of the tool is to assist authors in systematically and transparently assessing the conceptual richness and contextual thickness of data within primary qualitative studies. The richness tool evaluates the depth and detail of qualitative data in the studies included in a QES, focusing on contextual detail, data complexity, and the insights provided. The thickness tool measures the comprehensiveness and robustness of qualitative analysis, examining how well the analysis is supported by the data, the level of researcher reflexivity, and the coherence of the findings. The tool supports different QES methods.

Objectives of the data richness and thickness assessment Tool:

  • Systematic assessment: Provide a structured method for evaluating the richness and thickness of qualitative data from primary studies included in a QES, ensuring consistent assessments across different reviewers and studies.
  • Facilitating sampling: Facilitate the sampling of qualitative studies by identifying those studies with the richest and thickest data, thus prioritising studies that are most likely to contribute to a nuanced and comprehensive understanding of the research question.
  • Transparent reporting: Improve the transparency in how data richness and thickness are assessed and reported, which is crucial for the credibility and replicability of QES.
  • Guidance development: Offer practical guidance to review authors on the application of the tool, helping them discern and agree upon what constitutes rich and thick data in the context of their specific review.

February 2025: Cochrane endorsed the data richness and thickness assessment tool as optional for prospective authors following a recommendation from the Methods Executive, which was informed by the relevant Methods Group, Cochrane's Methods Support Unit, the Head of Methods and Evidence Synthesis/Deputy Editor-in-Chief, a Cochrane Review Group representative and the Methods Executive representative on Cochrane's Editorial Board.

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