Since many web users have posted their opinions and information without revealing their personal identities (i.e. demographics, social standing, or expertise), anonymity has become a common form of exchanging information in online communities, such as social media, Internet forums, social networks, etc. In the meantime, negative social consequences due to malicious comments or identity deception, have been resulted from anonymous activities in online social community. The current literature has found largely mixed results about the impact of anonymity on group outcomes. In order to clarify mixed results about anonymity in the current literature, this study proposes a new operational definition of anonymity which consists of three dimensions: unlinkability, unobservability, and pseudonymity. The data used in this study was collected from 238 online communities’ users through a web-based survey conducted in South Korea. The results show that unlinkability, unobservability and pseudonymity positively influence self-discrepancy, which in turn positively influences the quality and quantity of information sharing.