Really pushing my buttons: Affordances in block interfaces

Block-based languages are a useful scaffold for novice programmers to create syntactically correct code. However, block environments that attempt to represent feature-rich languages, such as Python or Java, face serious usability and pedagogical challenges. How can the affordances and controls of a block be exposed, without over-complicating the block's interface and obscuring its meaning to the user? In this paper, we visually explore a number of interface mechanisms to reconfigure blocks. We outline research questions to compare and contrast the advantages and disadvantages of these mechanisms, and call on the community to pursue these trade-offs further.