Critical media literacy demands understanding of the deeper meanings of media messages. Using a grounded theory approach, this study analyzed responses by first-year college students with no formal media literacy education to three types of video messages: an advertisement, a public relations message and a news report. Students did not exhibit nuanced understandings of message purpose or sender in any of three types of messages, and had particular difficulty distinguishing public relations and news messages. These results suggest a media literacy curriculum addressing distinctions between media formats, with emphasis on analysis of message intent and point of view, is needed. (Contains 3 tables.)