End-user development is a growing domain; however, few dedicated end-user development tools exist allowing end-users to incorporate their domain knowledge into software solutions. EUREQA is a design pattern driven UML class diagram modeling tool allowing end-user developers to create UML class diagram models reflecting their domain knowledge. The UML class diagram can be used as a basis for model-driven development. EUREQA was evaluated with 20 participants recording data through direct observation, screen recordings, the think-aloud protocol and semi-structured interviews. Half of the participants used EUREQA and the other half used the Microsoft Visio modeling tool. The authors found that EUREQA participants scored higher than Visio participants for this task and that skill had less effect on the EUREQA participants’ solutions. Specifically inexperienced EUREQA users struggled less when working with UML class diagram elements compared to Visio participants.