Resolving the theory of planned behaviour's ‘expectancy-value muddle’ using dimensional salience

The theory of planned behaviour is one of the most widely used models of decision-making in the health literature. Unfortunately, the primary method for assessing the theory's belief-based expectancy-value models results in statistically uninterpretable findings, giving rise to what has become known as the ‘expectancy-value muddle’. Moreover, existing methods for resolving this muddle are associated with various conceptual or practical limitations. This study addresses these issues by identifying and evaluating a parsimonious method for resolving the expectancy-value muddle. Three hundred and nine Australian residents aged 18–24 years rated the expectancy and value of 18 beliefs about posthumous organ donation. Participants also nominated their five most salient beliefs using a dimensional salience approach. Salient beliefs were perceived as being more likely to eventuate than non-salient beliefs, indicating that salient beliefs could be used to signify the expectancy component. The expectancy-value term was therefore represented by summing the value ratings of salient beliefs, an approach that predicted attitude (adjusted R 2 = 0.21) and intention (adjusted R 2 = 0.21). These findings suggest that the dimensional salience approach is a useful method for overcoming the expectancy-value muddle in applied research settings.