The promotion of the "Rule of Law" is a leading ambition of the EU's external action (Article 21 TEU). The dominant approach in most policy documents is to define the rule of law in terms of legal and institutional checklists. However, several authors have criticized this "anatomical" approach and have argued for a "sociological" approach. In this paper, I will discuss two empirical models of the rule of law. Most current studies follow the model of the "Rule of Law in Action." This approach is based on Roscoe Pound's distinction between the "law in the books" and the "law in action." I will argue that this conventional approach has several shortcomings. I will therefore introduce an alternative model, based on Eugen Ehrlich's concept of the "living law." The principal concern of the "Living Rule of Law" model is not the level of social support but rather the social definition of the rule of law. To assess the strengths and weaknesses of both approaches, I will apply both models in a case study about rule of law reform in a refugee camp on the Thailand-Burma border. It will be concluded that empirical research is essential to evaluate the EU's external action. Moreover, empirical studies based on the model of the Living Rule of Law support a legal pluralist approach, which focuses on the user perspective of citizens and which recognizes the contested notion of the rule of law across cultural borders.