New measures in marketing are invariably created by using a psychometric approach based on Churchill's “scale development” procedure. This paper aims to compare and contrast Churchill's procedure with Rossiter's content‐validity approach to measurement, called C‐OAR‐SE.
The comparison of the two procedures is by rational argument and forms the theoretical first half of the paper. In the applied second half of the paper, three recent articles from the Journal of Marketing (JM) that introduce new constructs and measures are criticized and corrected from the C‐OAR‐SE perspective.
The C‐OAR‐SE method differs from Churchill's method by arguing for: total emphasis on achieving high content validity of the item(s) and answer scale – without which nothing else matters; use of single‐item measures for “basic” constructs and for the first‐order components of “abstract” constructs; abandonment of the “reflective” measurement model, along with its associated statistical techniques of factor analysis and coefficient alpha, arguing that all abstract constructs must be measured as “formative”; and abandonment of external validation methods, notably multitrait‐multimethod analysis (MTMM) and structural equation modeling (SEM), to be replaced by internal content‐validation of the measure itself. The C‐OAR‐SE method can be applied – as demonstrated in the last part of the article – by any verbally intelligent researcher. However, less confident researchers may need to seek the assistance of one or two colleagues who fully understand the new method.
If a measure is not highly content‐valid to begin with – and none of the new measures in the JM articles criticized is highly content‐valid – then no subsequent psychometric properties can save it. Highly content‐valid measures are absolutely necessary for proper tests of theories and hypotheses, and for obtaining trustworthy findings in marketing.
C‐OAR‐SE is completely original and Rossiter's updated version should be followed. C‐OAR‐SE is leading the necessary marketing measurement revolution.
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