Utilizing data collected in a southern city of China, this study proposes and tests a model that examines two personality traits namely extraversion and neuroticism as antecedents of perceived risk, personal relevance (two dimensions of involvement) and familiarity, and the influence of familiarity on analysis and elaboration (two dimensions of expertise). Familiarity and expertise are utilized as two dimensions of prior knowledge. Findings reveal that extraversion’s effects on personal relevance and familiarity are moderate. Familiarity has strong impact on analysis but moderate impact on elaboration. The impact of neuroticism on perceived risk and familiarity are found to be weak. While personal relevance has a moderate effect on familiarity, perceived risk’s impact on familiarity is found to be weak.