Making sense of UML class model changes by textual difference presentation

Understanding the difference between two models, such as different versions of a design, can be difficult. It is a commonly held belief that the best way of presenting a model difference is by using graph or tree-based visualizations. We disagree and present an alternative approach where sets of low-level model differences are abstracted into high-level model differences that lend themselves to being presented textually. The results of preliminary user studies support our claim.