Predictions are that blogs will be the promotional tool of the future, if not now. The question remains: how credible are blogs as a source of consumer information? How do consumers perceive the credibility of blogs from different sources when making purchase decisions and product evaluations? The primary objective of the present study is to assess validity and reliability of a set of Semantic Differential scales purported to measure perceived credibility of different types of blogs. Confirmatory factor analysis via LISREL8.5 package was used to obtain appropriate statistics for convergent validity, discriminant validity, and composite reliability. In general, the scales used to measure the two hypothesized factors (source credibility and content credibility) for each type of blog achieved a satisfactory level of construct validity.