“…Although studies have found that expectancy-value models, such as the Theory of Planned Behavior (TPB: Ajzen, 1985), predict intention well (McEachan et al, 2011), there is still a large proportion in behavior left unexplained (Armitage and Conner, 2001). Unfortunately, the use of correlational data, which insufficiently validates a theory (Weinstein, 2007), far outweighs the number of studies attempting to change these processes through the development of interventions (Hardeman et al, 2002). This is despite the prevalence of clear methodological guidelines on belief alteration (Ajzen, 1991).…”