Political knowledge is a central concept in the study of public opinion and political behavior. Yet what the field collectively believes about this construct is based on dozens of studies using different indicators of knowledge. We identify two theoretically relevant dimensions: atemporaldimension that corresponds to the time when a fact was established and atopicaldimension that relates to whether the fact is policy-specific or general. The resulting typology yields four types of knowledge questions. In an analysis of more than 300 knowledge items from late in the first decade of the 2000s, we examine whether classic findings regarding the predictors of knowledge withstand differences across types of questions. In the case of education and the mass media, the mechanisms for becoming informed operate differently across question types. However, differences in the levels of knowledge between men and women are robust, reinforcing the importance of including gender-relevant items in knowledge batteries.