Due to the rapid growth of internet technologies and communication networks, product vendors and companies are identifying web as a platform for launching and promoting their products globally. The user communities of web utilize these forums as a tool for posting and delivering their opinion about products. In such circumstances, techniques based on opinion mining play significant roles which include, understanding the opinions posted by the users, analyzing user reviews, extracting useful patterns, assisting decision making process etc. This paper analyses the genuinity of opinions expressed by web users. © 2013 Springer-Verlag.