The measurement and analysis of people's knowledge on scientific topics, such as climate change, is challenging for researchers. One reason is that objectives are multi-dimensional and that probability is inherent. Moreover, uncertainties can exist on the individual's level among the public, but are rarely grasped by existing scales. Therefore, researchers must thoroughly consider what to measure and how. This paper theorizes five different dimensions of climate change knowledge. Three response scales including different degrees of confidence are applied on data from a German online survey (n=935); empirical results of multivariate regression analyses on attitudes are compared. Results highlight the importance of distinctively measuring dimensions and types of knowledge.