Editing Questionnaire Items using the Delphi Method: Integrating Qualitative and Quantitative Methods

Abstract

The authors of this article argue that instrument development studies can be situated within constructive realism, an intermediary ontology between the representative constructed items and objectivist goals of measurement. The Delphi method uses constructionist processes by gathering expert opinions about the variable they wish to measure. Despite its popularity, little pragmatic guidance exists for researchers using the method in instrument development studies and authors of instrument development studies rarely describe the strategies used to decide when to keep, edit, or delete items when merging both quantitative and qualitative assessments of the developing items. This article, therefore, describes mixed methods decision-making strategies as they were implemented during the Delphi phase of the Situated Academic Writing Self-Efficacy Scale (SAWSES) validation project. Five case-study items are presented to highlight the strategies used to integrate the qualitative and quantitative data provided by a Delphi panel. Data were integrated by categorizing the quantitative data as having strong evidence for inclusion, deletion, or neutrality. Concurrently, qualitative data were integrated with the quantitative data by contemplating panellists’ individual and collective opinions about item value and wording, as well as stream-of-consciousness reflections from panellists about the nature of writing self-efficacy. This article contributes to the literature by describing, through use of specific examples, how qualitative and quantitative data can be effectively integrated to make decisions in mixed methods instrument development research and should be useful for all beginning and seasoned researchers attempting tool development.