Statistical and judgmental criteria for scale purification

Purpose “Scale purification” – the process of eliminating items from multi-item scales – is widespread in empirical research, but studies that critically examine the implications of this process are scarce. The goals of this research are threefold: to discuss the methodological underpinning of scale purification, to critically analyze the current state of scale purification in supply chain management (SCM) research and to provide suggestions for advancing the scale-purification process. Design/methodology/approach A framework for making scale-purification decisions is developed and used to analyze and critically reflect on the application of scale purification in leading SCM journals. Findings This research highlights the need for rigorous scale-purification decisions based on both statistical and judgmental criteria. By applying the proposed framework to the SCM discipline, a lack of methodological rigor and coherence is identified when it comes to current purification practices in empirical SCM research. Suggestions for methodological improvements are provided. Research limitations/implications The framework and additional suggestions will help to advance the knowledge about scale purification. Originality/value This paper demonstrates that the justification for scale purification needs to be driven by reliability, validity and parsimony considerations, and that this justification needs to be based on both statistical and judgmental criteria.