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NOMINATE (an acronym for Nominal Three-Step Estimation) is a multidimensional scaling application developed by political scientists Keith T. Poole and Howard Rosenthal in the early 1980s to analyze preferential and choice data, such as legislative roll-call voting behavior.〔Poole, Keith T. and Howard Rosenthal. 1983. "A Spatial Model for Legislative Roll Call Analysis." GSIA Working Paper No. 5- 83-84. http://voteview.com/Upside_Down-A_Spatial_Model_for_Legislative_Roll_Call_Analysis_1983.pdf〕〔Poole, Keith T. and Howard Rosenthal. "A Spatial Model For Legislative Roll Call Analysis." ''American Journal of Political Science'', May 1985, 357-384.〕 As computing capabilities grew, Poole and Rosenthal developed multiple iterations of their NOMINATE procedure: the original D-NOMINATE method, W-NOMINATE, and most recently DW-NOMINATE (for dynamic, weighted NOMINATE). In 2009, Poole and Rosenthal were named the first recipients of the Society for Political Methodology's Best Statistical Software Award for their development of NOMINATE, a recognition conferred to "individual(s) for developing statistical software that makes a significant research contribution."〔The Society for Political Methodology: Awards. http://polmeth.wustl.edu/about.php?page=awards〕 ==Procedure== The main procedure is an application of multidimensional scaling techniques to political choice data. Though there are important technical differences between these types of NOMINATE scaling procedures;〔Description of NOMINATE Data. http://www.voteview.com/page2a.htm〕 all operate under the same fundamental assumptions. First, that alternative choices can be projected on a basic, low-dimensional (often two-dimensional) Euclidean space. Second, within that space, individuals have utility functions which are bell-shaped (normally distributed), and maximized at their ideal point. Because individuals also have symmetric, single-peaked utility functions which center on their ideal point, ideal points represent individuals' most preferred outcomes. That is, individuals most desire outcomes closest their ideal point, and will choose/vote probabilistically for the closest outcome. Ideal points can be recovered from observing choices, with individuals exhibiting similar preferences placed more closely than those behaving dissimilarly. It is helpful to compare this procedure to producing maps based on driving distances between cities. For example, Los Angeles is about 1,800 miles from St. Louis; St. Louis is about 1,200 miles from Miami; and Miami is about 2,700 miles from Los Angeles. From this (dis)similarities data, any map of these three cities should place Miami far from Los Angeles, with St. Louis somewhere in between (though a bit closer to Miami than Los Angeles). Just as cities like Los Angeles and San Francisco would be clustered on a map, NOMINATE places ideologically similar legislators (e.g., liberal Senators Barbara Boxer (D-Calif.) and Al Franken (D-Minn.)) closer to each other, and farther from dissimilar legislators (e.g., conservative Senator Tom Coburn (R-Okla.)) based on the degree of agreement between their roll call voting records. At the heart of the NOMINATE procedures (and other multidimensional scaling methods, such as Poole's Optimal Classification method) are algorithms they utilize to arrange individuals and choices in low dimensional (usually two-dimensional) space. Thus, NOMINATE scores provide "maps" of legislatures. Using NOMINATE procedures to study congressional roll call voting behavior from the First Congress to the present-day, Poole and Rosenthal published ''Congress: A Political-Economic History of Roll Call Voting''〔Poole, Keith T. and Howard Rosenthal. 1997. ''Congress: A Political-Economic History of Roll Call Voting.'' New York: Oxford University Press.〕 in 1997 and the revised edition ''Ideology and Congress''〔Poole, Keith T. and Howard Rosenthal. 2007. ''Ideology and Congress''. New Brunswick, NJ: Transaction Publishers. http://www.transactionpub.com/title/Ideology-and%20Congress-978-1-4128-0608-4.html〕 in 2007. Both were landmark works for their development and application of the use of sophisticated measurement and scaling methods in political science. These works also revolutionized the study of the American politics and, in particular, Congress. Their methods provided political scientists—for the first time—quantitative measures of Representatives' and Senators' ideology across chambers and across time. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NOMINATE (scaling method)」の詳細全文を読む スポンサード リンク
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