ContextMisuse case modeling is a well-known technique in the domain of capturing and specifying functional security requirements. Misuse case modeling provides a mechanism for security analysts to consider and account for security requirements in the early stages of a development process instead of relying on generic defensive mechanisms that are augmented to software systems towards the latter stages of development. ObjectiveMany research contributions in the area of misuse case modeling have been devoted to extending the notation to increase its coverage of additional security related semantics. However, there lacks research that evaluates the perception of misuse case models by its readers. A misread or misinterpreted misuse case model can have dire consequences downstream leading to the development of an insecure system. MethodThis paper presents an assessment of the design of the original misuse case modeling notation based on the Physics of Notations framework. A number of improvements to the notation were suggested. A survey and a controlled experiment were carried out to compare the cognitive effectiveness of the new notation in comparison to the original notation. ResultsThe survey had 55 participants for have mostly indicated that the new notation is more semantically transparent than the original notation. The results of the experiment show that subjects reading diagrams developed using the new notation performed their tasks an average 6min quicker, while in general the subjects performed their tasks in approximately 14.5min. The experimental tasks only required subjects reading diagrams and not creating them. ConclusionThe main finding of this paper is that the use of colors and icons has improved the readability of misuse case diagrams. Software engineering notations are usually black and white. It is expected that the readability of other software notations will improve if they utilize colors and icons.