Results from exploratory factor analysis (EFA) demonstrated that the data set supported 4 blog quality criteria with 35 indicators. The users’ perceptions of quality criteria are content quality, usability, authority, and blog credibility. Each criterion has a different numbers of indicators as shown in Figure 1. However, quality is related to human perception and there are individual differences, the personal characteristics (gender, education level, age, profession, purposes of use, and specific interests) affected the users’ choices of criteria for evaluating the quality of blogs.