This paper draws upon a model of the publicness of publicly owned and managed spaces by means of fuzzy logic modelling. The value of this approach is that it is practical in simplifying and emphasizing both the interdependent nature of the concept of publicness and its complexity. The proposed model aims to effectively evaluate and compare the publicness of public space. The paper highlights different methodologies in understanding this publicness by considering various conceptual approaches at the heart of the debate about public space. In doing so, the paper is organized into four main parts. The first part considers the complex and fuzzy nature of the concept. The second presents the proposed model of publicness based on management, access and user dimensions by analyzing the leading discourse and previous models of publicness. The third part draws upon research methodology and fuzzy logic modelling, and the fourth part explains the findings of the case study in Istanbul.