Expertise of Technology acceptance model

        Expertise can be defined as "the perceived ability of the source to make valid assertions" (McCracken 1989, p. 311). It describes the extent to which the source is able to provide valid information (Hovland et al., 1953). This extent can be determined by assessing source’s aspects, such as such as knowledge, experience, or skills (Erdogan, 1999). Farr (2007) propose that expertise can be examined in two ways, basing on its two main characteristics, technical and practical competence (Braunsberger & Munch, 1998, p.24). Technical competence concerns the skilfulness of the source and its possession of special knowledge (Braunsberger & Munch, 1998. p.24). It can be acquired by “training, reading, formal education and scholarly pursuits’’ (Farr, 2007, p. 244). As opposed to technical competence, practical competence refers to the experience and skills possessed from direct participations in activates and can be achieved through trial and error process and practise (Braunsberger & Munch, 1998, p.24). Farr & White (2003) showed that both technical and practical competences contribute to the evaluation of perceived expertise. When a source has little practical competence, the technical competence had a small effect, however when a source is high in practical competence, technical competence was found to have a significant effect on the perceived credibility (Farr, 2007, p.244).

        However, self-proclaimed experts and real experts could present comparable level of knowledge and be perceived by consumers as similar. It means that an online reviewer who is a professional in a given field could be seen as having the same degree of expertise as a self-taught man. Particularly in the context of online environment, consumers may have difficulties to assess the expertise of an online reviewer. Many times the Internet anonymity makes it impossible to identify reviewer’s qualifications, because reviewers commonly use nicknames instead of their real names and provide scarce information about their background (Chang & Chuang, 2011, p.16; Zhao et al., 2015, p.1347). However, recipients can evaluate the reviewer’s expertise in a certain topic of interest by evaluating cues that signal expertise, such as the specific knowledge or strength of arguments embedded in the message (Clark et al., 2012, p.91; Cosenza et al., 2015, p.73).

        Source expertise was found to have a significant influence on information adoption (Cheung et al., 2008). The information source that is high in expertise is more persuasive than a source low in expertise (Maddux & Rogers, 1980). Thus, information sources perceived as “experts” will be more influential than non-expert ones (Braunsberger & Munch, 1998, p.25). Moreover, a source high in expertise can positively influence the attitude towards the source (Maddux & Rogers, 1980; McGinnies & Ward 1980), attitude towards the message (Homer & Kahle, 1990), and attitude toward information usefulness (Gunawan, 2015; Sussman & Siegal, 2003). Furthermore, it also reported that source expertise influences consumers’ attitude, behavioural intention and actual behaviour (McGinnies & Ward, 1980). Therefore, source expertise is a crucial element of the information persuasiveness (Dholakia & Sternthal, 1977). The measurement used to evaluate source expertise was adopted from Ohanian (1990) and included 3 items, namely, “expert”, “knowledgeable” and “qualified”. These attributes were chosen because they are considered to be clear indicators of expertise as well as have high loadings (Ohanian, 1990, p.43).