Theory	Core Constructs	Definitions
The Theory of Reasoned Action (TRA) Adopted from social psychology, TRA is one of the most fundamental and basic and influential theories of human behaviours. The theory has been used to predict a broader range of behaviours. Davis et al. (1989) applied TRA to individual acceptance of technology and observed that the variance explained was largely in line with studies that had employed TRA in the context of other behaviours.	Attitude toward Behaviour	“An individual’s positive or negative feelings (evaluative affect) about performing the target behaviour” ( Venkatesh et al., 2003 ).
	Subjective Norm	“The person’s/consumers perception that most people who are important to him think he should or should not perform the behaviour in question ( Venkatesh et al., 2003 ).
The Technology Acceptance Model (TAM) TAM is tailor made to Information System contexts, and was designed to predict information technology acceptance and usage on the job for the consumers, where the researchers completely depend on this theory. Unlike TRA, the final conceptualization of TAM excludes the attitude construct in order to better explain intention parsimoniously. TAM 2 extended TAM by including subjective norm as an additional predictor of intention in the case of mandatory settings ( Venkatesh et al., 2003 ). TAM has been widely applied to a diverse set of technologies and users.	Perceived Usefulness	“The degree to which a person believes that using a particular system would enhance his or her job performance” ( Davis et al., 1989: p. 320 ).
	Perceived Ease of Use	“The degree to which a person believes that using a particular system would be free of effort” ( Davis et al., 1989: p. 320 ).
	Subjective Norm	Adapted from TRA/TPB. Included in TAM 2 only.
The Motivational Model (MM) A significant contribution for research in psychology has supported general motivation theory as an explanation for behaviour in consumers. Several studies have examined motivational theory and adopted it for specific contexts in the research. Venkatesh et al. (2003) present an excellent review of the fundamental tenets of this theoretical base. Within the information systems domain, Davis et al. (1989) applied motivational theory to understand new technology adoption and use ( Venkatesh et al., 2003 ).	Extrinsic Motivation	The perception that users will want to perform an activity “because it is perceived to be instrumental in achieving valued outcomes that are distinct from the activity itself, such as improved job performance, pay, or promotions” ( Davis et al., 1989 ).
	Intrinsic Motivation	The perception that users will mostly want to perform an activity “for no apparent reinforcement other than the process of performing the activity per se” ( Davis et al., 1989 ).