方法对比

	Wordfish Scaling	Manifesto Coding	Wordscores
领域	Political Science	Political Science	心理测量学
方法族	Latent structure	Process / pipeline	Latent structure
起源年份	2008	2001	2003
提出者	Jonathan Slapin and Sven-Oliver Proksch	Manifesto Research Group / Comparative Manifesto Project (CMP/MARPOR)	Michael Laver, Kenneth Benoit, John Garry
类型	Unsupervised latent-position model for word-count data	Quantitative content analysis of party manifestos	Text analysis and dimension reduction
开创性文献	Slapin, J. B., & Proksch, S.-O. (2008). A Scaling Model for Estimating Time-Series Party Positions from Texts. American Journal of Political Science, 52(3), 705–722.	Budge, I., Klingemann, H.-D., Volkens, A., Bara, J., & Tanenbaum, E. (2001). Mapping Policy Preferences: Estimates for Parties, Electors, and Governments 1945–1998. Oxford: Oxford University Press. ISBN: 9780199244003	Laver, M., Benoit, K., & Garry, J. (2003). Extracting policy positions from political texts using words as data. American Political Science Review, 97(2), 311-331.
别名	Wordfish text scaling, Poisson scaling of texts, Unsupervised text scaling, Wordfish position estimation	CMP coding, MARPOR coding, Manifesto content analysis, Party manifesto coding	—
相关	4	4	5
摘要	Wordfish scaling is an unsupervised text-as-data method that estimates a single latent position for each political document — a party manifesto, a legislative speech, a press release — directly from its word frequencies, without any reference texts or hand coding. Introduced by Slapin and Proksch in 2008, it models word counts as draws from a Poisson distribution whose rate depends on a document position and word-specific parameters, recovering, for example, a left–right ordering of parties purely from how often each word appears in each text.	Manifesto coding is the quantitative content-analysis methodology of the Comparative Manifesto Project (CMP/MARPOR) for measuring parties' policy preferences from their election manifestos. Trained coders break each manifesto into quasi-sentences and assign every unit to one of a fixed set of policy categories. Counting how often each category appears yields salience measures, and combining pro- and anti- categories produces position scores such as the left–right RILE index, giving comparable estimates of party positions across more than fifty democracies since 1945.	Wordscores is a text-based scaling method developed by Laver, Benoit, and Garry (2003) that estimates the policy positions of political actors based on word frequencies in their texts. By comparing word usage in reference texts of known positions with test texts, the method infers the latent political dimension of any document without requiring manual coding or training data.