This 2013 chapter by Küster and Kappas explores methods for measuring emotions in online communities. The authors examine three primary approaches: analyzing large datasets of online text using automated tools like LIWC and SentiStrength, soliciting self-reported emotional experiences from individuals, and recording physiological responses. While automated text analysis offers scalability, limitations arise from contextual ambiguity and sampling bias. The chapter emphasizes the need to integrate these methods to gain a more complete understanding of online emotions, advocating for future research incorporating multimodal data from video and other sources. Ultimately, the authors highlight the complex interplay between text, subjective experience, and physiological responses in shaping online emotional expression.