Design of Social Media for Health Behavior Change: An Ontological Approach ThirumalaiMohanraj 2016 Use of social media for health behavior change is a complex interdisciplinary problem and has seen a rapid growth in the recent years. Following a systematic approach, an ontological framework was created to conceptualize a lens which exposes the various complexities of this problem. The framework provides an information systems point of view on the research on the use of social media for health behavior change. The framework was then used to systematically analyze the current state of the research on this problem by creating an ontological topography of all extant literature. The ontological topography was created at monadic, dyadic and triadic levels and helped expose the bright, light and blind/blank spots in the current body of research. The ontological topography and literature review shed light on the inadequacies of the current research which places social media features at the periphery or compromise by eliminating traditional online health behavior change features. A lack of research which intends to make use of users’ existing social networks was also highlighted. These findings led to a research objective of designing a new prototype for online health behavior change system which enables delivery of a holistic behavior change intervention within a mainstream social networking site (Facebook), using its API. An evaluation of the usability, engagement, perceived social support and perceived privacy of the prototype was performed. Study findings illustrated that the designed prototype has good usability and resulted in a significant increase in social support. Program engagement parameters have also been found to be better than established benchmarks. The qualitative interviews revealed that the users were able to appreciate the tailored nature of the content provided through the prototype, being able to connect with their existing social contacts and also make new connections. Users were also able to point out the pitfalls of the prototype and offered suggestions on how to improve the design further. Future research efforts could benefit from incorporating the ontological framework with the prototype (with minimal configuration changes) to rapidly produce the required solutions to achieve a variety of health behavior change solutions for diverse populations.