CodeMaster UI Design - App Inventor: A Rubric for the Assessment of the Interface Design of Android Apps developed with App Inventor

One way to teach computational thinking in K-12 is through the development of mobile applications with App Inventor. Although there exist several courses in this context, there is still a need for support for the evaluation of the applications created by the students. Specifically for the evaluation of the interface design there are still no automated approaches available. Thus, in order to support the evaluation of the visual design of apps based on its compliance with guidelines, we developed CodeMaster UI Design Rubric - App Inventor in the context of computing education in school. In order to facilitate its application in practice, the evaluation of applications created with App Inventor has been automated. The reliability and validity of the rubric were evaluated through an evaluation with 978 projects from the App Inventor Gallery. The results indicate that the CodeMaster UI Design Rubric - App Inventor can be considered reliable (Cronbach's alpha = 0.72). In terms of construct validity, there is evidence of convergent validity. However, we identified the need to revise some criteria due to a lack of correlations with UI design element categories. Based on these results, the rubric is being improved and larger-scale studies are being carried out.