Political knowledge today is studied primarily at the explicit level. Measures of political knowledge often rely on testing whether voters are aware of various "facts" about political life, such as the names and offices of prominent political actors, the institutional structures of the political system, and the ideological or policy differences between the major political parties (e.g., Delli Carpini and Keeter 1996). These various kinds of political information are considered to be important by political scientists and other social scientists because they facilitate the informed voting decisions that are needed to hold elected leaders accountable (e.g., Lau and Redlawsk 2006; Pande 2011).
Since the language of political inquiry seems to be inescapably metaphorical, the question necessarily arises as to how metaphors of various types, including models, enter into the composition and expression of political knowledge. The solutions that have been most influential in contemporary political science can be called the verificationist and constitutivist views of political metaphor. While both views contain important elements of truth, there are fundamental difficulties in each that require the search for a more satisfactory view. An alternative view of metaphor and political knowledge is developed by reference to four main problems: Why is political speech metaphorical? How do metaphors make political things manifest? How are political metaphors tested? and Are metaphors indispensable to political expression and political knowledge?
Survey research shows that voters know very little about politics. Left unexamined is whether political knowledge is a distinct type of knowledge when compared to other subjects. We seek to establish a baseline by putting political knowledge into a broader context. We show that our respondents' knowledge about politics is similar in construction to their knowledge about other subjects, such as shopping, sports, popular culture, geography, economics, and the rules of the road. We conclude that knowledge of politics largely resides on the same dimension as other knowledge topics, implying that knowledge of politics is not a unique construct.
Political knowledge has emerged as one of the central variables in political behavior research, with numerous scholars devoting considerable effort to explaining variance in citizens' levels of knowledge and to understanding the consequences of this variance for representation. Although such substantive matters continue to receive exhaustive study, questions of measurement also warrant attention. I demonstrate that conventional measures of political knowledge—constructed by summing a respondent's correct answers on a battery of factual items—are of uncertain validity. Rather than collapsing incorrect and "don't know" responses into a single absence-of-knowledge category, I introduce estimation procedures that allow these effects to vary. Grouped-data multinomial logistic regression results demonstrate that incorrect answers and don't knows perform dissimilarly, a finding that suggests deficiencies in the construct validity of conventional knowledge measures. The likely cause of the problem is traced to two sources: knowledge may not be discrete, meaning that a simple count of correct answers provides an imprecise measure; and, as demonstrated by the wealth of research conducted in the field of educational testing and psychology since the 1930s, measurement procedures used in political science potentially result in "knowledge" scales contaminated by systematic personality effects.