A User-centered Approach for Modeling Web Interactions Using Colored Petri Nets

Interactions are communication acts which take place between at least two agents and result in information interchange. To represent these activities, formal methods can be used to model interaction flows and Colored Petri Nets (CPNs) are a handy formal language with graphical notation for modeling systems. This paper introduces wiCPN (Web Interaction Modeling Using Colored Petri Nets), a language based on CPNs for representing Web interactions with improved notation. Our proposal is first presented with its proper refinements over traditional CPNs. Next, we have applied the approach for modeling the interaction of Classroom eXperience’s (CX) Web front-end, a real u-learning environment. As CX is an educational system developed to assist instructors and students during academic activities, we verified the developed model’s reachability to ensure it was able to represent users different access levels. We also validated our proposal with user experiments, comparing it with UML. Our designed model represented CX’s interaction correctly, considering user access levels and maintaining an understandable notation. Results indicate advantages of wiCPN over UML for modeling interactive interfaces. By gathering strengths of Petri Nets with a higher level graphical notation, wiCPN propitiated better understanding of the model, representing interaction in a structured and intuitive way.