Political knowledge is one of the most influential variables in political science. However, scholars still grapple with its theoretical meaning and how to measure it best. I address the deeply contested issue of whether knowledge should be measured with either an open-ended or closed-choice measure. Beyond exploring the effects of these contested approaches on estimates of overall levels of mass knowledge, I also study how they influence who is deemed knowledgeable and explore how this affects a variety of attitudes. I find that measurement dramatically matters on all of these dimensions. In short, the results reported here raise important questions about the validity of knowledge indices and also have implications for the general study of political attitudes and behavior.
International Journal of Public Opinion Research, 2015, Vol 27, Issue 1, p. 1-21