People often discount their own information and imitate others though a process known as herd behavior. This paper investigates herd behaviors in technology adoption and continued use. Specifically, this paper concerns how people may follow others when choosing to adopt information systems and how they may revise this initial decision at the post-adoption stage. Herd literature suggests that people may discount their own beliefs when making adoption decisions and that these adoption decisions are fragile and can be easily reversed at the post-adoption stage. This has implications for existing information systems (IS) research on initial adoption and postadoption system use. We develop a new concept called level of herding to measure to what degree a person follows the actions of others, rather than his/her own beliefs, then adopting a new technology. A research model is developed. A longitudinal survey is being conducted to examine the research model, using PBwiki, an online wiki system, as the research technology. Findings from this research can help us understand herd behavior in the adoption and continued use of technology.