Social marketing theory measurement precision: a theory of planned behaviour illustration

Abstract

Purpose: In response to calls for theory use and a more reflexive turn in social marketing, this paper aims to draw on previously executed studies. In line with dominant social marketing downstream-focussed practice, the explanatory power of a commonly used theory, namely, the theory of planned behaviour (TPB), was empirically examined across three different contexts and critically assessed to guide future research practice. Design/methodology/approach: TPB measures were drawn from prior studies, and inconsistent item use across contexts was observed. Quantitative studies involving from 876 to 3,191 respondents underpin this study. Each study focussed on a different behaviour, namely, walking to and from school, binge drinking and packing fruits and vegetables into lunchboxes. Hierarchical multiple linear regressions were used for data analysis. Findings: Item use was mixed, construct reliability was not consistent and consequent findings indicated that TPB explained walking to and from school and binge drinking, but it did not explain packing fruits and vegetables into lunchboxes. Originality/value: Theory use is recommended to enhance intervention outcomes. However, theory application remains scarce in social marketing. Moreover, when theory is used, consistent measures are not used; items are removed from constructs to obtain model fit and constructs used within the theory differ. The current study draws from three studies, all of which applied TPB to explain behaviours. Mixed outcomes were observed when the same analytical process was applied using the available measures and constructs. Close investigation of the measures used across the three studies highlights one explanation for mixed findings. In the absence of consistent application of the theory, drawing definitive conclusions about a theory’s effectiveness is premature. Precise application of theoretical constructs is needed to deliver theoretically derived understanding.