手法を比較

	Scott's Pi	Manifest Content Analysis
分野	Communication	Communication
系統	Process / pipeline	Process / pipeline
提唱年	1955	1952
提唱者	William A. Scott	Bernard Berelson; codified by Klaus Krippendorff
種類	Chance-corrected agreement coefficient for two coders on nominal scales	Systematic quantitative coding of explicit message content
原典	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
別名	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
関連	4	5
概要	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.