Although anonymity on the Internet has often been touted as the key to self-expression and identity development for the Net Generation, empirical support for this assumption has seldom been tested. This dissertation was a two study endeavor to develop 1) the Internet & Anonymity Measure (IAM) and 2) the Online Identity Development Model to assess the role of online anonymity in predicting identity exploration and commitment. Through a series of exploratory and confirmatory factor analyses in Study 1 and 2, the IAM emerged as a reliable measure to assess individuals' 1) perception of online anonymity, or the understanding and perception that online users can truly be unidentifiable and anonymous, 2) perception of offline-online disparities, or the perception that the Internet allows individuals to present themselves differently or inaccurately online versus offline, and 3) online expressiveness, or one's willingness to self-disclose in an online context rather than in face-to-face interactions.

For Study 2, an online identity development model was tested to examine the direct and indirect influences of online anonymity on identity development processes. The results directly linked online anonymity to greater online expressiveness and an increased perception of offline-online disparities. Structural equation modeling results showed that online anonymity was indirectly related to identity processes through the perception of offline-online disparities. That is, online disparities function as a mediator and proximal predictor of identity development processes. These results were supported at the general Internet context and within the context of instant messaging.