方法对比

	Scott's Pi	Manifest Content Analysis
领域	Communication	Communication
方法族	Process / pipeline	Process / pipeline
起源年份	1955	1952
提出者	William A. Scott	Bernard Berelson; codified by Klaus Krippendorff
类型	Chance-corrected agreement coefficient for two coders on nominal scales	Systematic quantitative coding of explicit message content
开创性文献	Scott, W. A. (1955). Reliability of content analysis: The case of nominal scale coding. Public Opinion Quarterly, 19(3), 321–325.	Krippendorff, K. (2004). Content Analysis: An Introduction to Its Methodology (2nd ed.). Thousand Oaks, CA: Sage. ISBN: 9780761915454
别名	Scott pi, Scott's index of reliability, Pi reliability coefficient, Scott Pi Katsayısı	Quantitative manifest coding, Surface-content analysis, Manifest-level content analysis, Berelson content analysis
相关	4	5
摘要	Scott's pi is a chance-corrected coefficient of intercoder agreement for two coders working on a nominal scale, introduced by William Scott in 1955 specifically for content analysis. It improves on raw percent agreement by subtracting the agreement two coders would reach by chance, where chance is estimated from a single pooled distribution of categories shared by both coders rather than from each coder's separate marginals.	Manifest content analysis is a quantitative research technique that systematically counts the explicit, surface-level features of communication messages — words, sources, themes, images, or actors that are directly visible in the text or media artifact — according to a predefined coding scheme. Rooted in Bernard Berelson's classic definition of content analysis as the 'objective, systematic, and quantitative description of the manifest content of communication,' it is one of the foundational empirical methods of mass communication and media research.