Two visualizations of OCL: a comparison

We compare two visualizations of OCL, VisualOCL and Constraint Diagrams, and establish some of their benefits and weaknesses. These two notations were designed to fit in to the diagrammatic modelling paradigm. We introduce a simple case study, with constraints written in both natural language and OCL, and visualize these constraints using VisualOCL and Constraint Diagrams. Using a set of criteria which is based on cognitive, syntactic and semantic questions, we compare the notations, with reference to the sample constraints