From App Inventor to Java: A Strategy for Mediating the Transition

In school informatics, visual programming environments are common when teaching fundamentals of programming. Such visual tools were designed to make the programming process easier for novices (in comparison with textual-oriented development tools). In our research, we deal with issues of teaching programming within the upper secondary education. We teach students to program Android mobile applications using the MIT App Inventor 2. Benefits of visual programming are being confirmed throughout the classes repeatedly. However, we observed that students with more serious interest in programming tend to be less enthusiastic about using the MIT App Inventor 2 in a long-term period as their ambition to work in a more professional manner is very strong. The transition to a textual programming in Java is objectively difficult and may be rather frustrating for students. In this article, we suggest a strategy for bridging the gap between visual programming in MIT App Inventor 2 and writing the application's source code in Java to mediate a fluent transfer of knowledge from one context to another. We propose to start with learning activities focused on analyzing and adapting the Java source codes of sample applications that are already familiar to students. These scaffoldings provided by the App Inventor Java Bridge code generator could help students with recognizing the analogies. Next, students should be involved in small scaled programming assignments focused on learning Java and using the supporting App Inventor Java Bridge library directly. The knowledge and skills mediated by Java Bridge technology put students into their zone of proximal development, so they can solve more complex tasks independently and their learning performance is likely to be better.