Learning UML Sequence Diagrams with a New Constructivist Pedagogical Tool: SD4ED

Increasingly, students from many different majors are taking foundational courses in Software Engineering (SE) where modelling forms a major part. Novices with limited Object-Oriented (OO) programming skills often find OO modelling concepts abstract and difficult when compared to other topics. In particular, dynamic modelling of sequence diagrams (SDs) was shown to pose the most difficulties when novices learn UML modelling. Novices often do not consider how SDs are constrained by static models such as class diagrams and fail to meet some of the postconditions specified in the use case descriptions. These problems are exacerbated for instructors teaching large classes unable to give adequate formative feedback in the early stages, leading to poor student satisfaction and learning outcomes. This paper explores the efficacy of using a constructivist-learning tool in large classes able to give immediate feedback in the early stages. In this paper, we report our experience of developing an interactive pedagogical tool called SD4ED to help students learn SDs. The main novelty of our approach is the mechanism devised to provide instant feedback while students are creating the SDs based on the constraints for the underlying static model, postconditions specified for the underlying use case and the current knowledge state aggregating past messages. Unlike other UML tools developed in the past, our tool helps students to create consistent and complete models using a constructivist approach. Our pre- A nd post-tests and survey feedback showed substantially improved learning outcomes and student satisfaction.