Media richness theory is a well known theory in media adoption and use. In recent years, it has gone through much empirical examination; however, some aspects of the theory still remain largely untested. In the current study, we investigated a core premise of the theory that there exists an inherent and fixed lean-rich continuum of communication media. Our results indicated that media richness was not inherent and fixed as assumed by media richness theory. Instead, with the social constructions shared among communicators, such as the shared group goals generated in this study, a lean CMC medium could be transformed into a rich one, so that rich information could be conveyed through this supposedly lean CMC medium.