This document summarizes various audience research theories that can be used to define target audiences. It discusses demographic and psychographic profiling methods from theorists like Young and Rubicam to segment audiences. More detailed profiling scales from Mosaic UK are presented. The document also covers uses and gratification research on why audiences engage with media, as well as Stuart Hall's audience reception theory and Ien Ang's work on dominant ideology and social debate. The conclusion states that understanding audience research helps media producers appeal to target groups and define appropriate content.