This document discusses defining and researching audiences. It explains that quantitative research uses statistical analysis of closed questions to understand things like readership rates. Qualitative research takes a more personal approach through open-ended interviews, focus groups, and questionnaires to understand what audiences like and dislike. Audience profiles categorize demographics like age, gender, income level, education, and location to effectively target advertising. Understanding psychographics, socioeconomic status, and geodemographics provides insight into lifestyles and spending habits for narrowing the target market. The document provides examples of audience data and outlines how mainstream and niche audiences differ in size and specificity of interests.