Pub. date: 2011 | Online Pub. Date: October 04, 2011 | DOI: 10.4135/9781412994163 | Print ISBN: 9781412959636 | Online ISBN: 9781412994163| Publisher:SAGE Publications, Inc.About this encyclopedia
Analysis of Variance
Erin Hartman & Adrienne Hosek
Analysis of variance (ANOVA) is a method for decomposing variance in a measured outcome into variance that can be explained, such as by a regression model or an experimental treatment assignment, and variance that cannot be explained, which is often attributable to random error. Using this decomposition into component sums of squares, certain test statistics can be calculated that can be used to describe the data or even justify model selection. Lab experiments have become increasingly popular in political science, and ANOVA is a useful tool for analyzing such experiments. In recent years, there have been a number of laboratory experiments on the effects of campaigning and media advertising. Nicolas Valentino, Vincent Hutchings, and Ismail White (2002), Diana Mutz and Byron Reeves (2005), and Ted Brader (2005) have all performed lab experiments that aim to determine the effect that campaigning and advertising in media have on voters views and decisions. ...