A Proposal of Constant Modification Problem for Beginners to Start Scratch Programming

Scratch is a block-based programming language developed by MIT, that can easily create digital stories, games and interactive animations. It is found that the experience and knowledge of learning Scratch may facilitate learning more advanced programming languages. However, beginners may be completely clueless and uninspired to get started with Scratch. Modifying a Scratch project is preferred than creating a new one for a beginner. In this paper, we propose a Constant Modification Problem (CMP) as a type of practices for Scratch learning. We choose five Scratch games to generate CMP instances. Each question in CMP asks to answer the modification of a constant in the code. A CMP instance consists of the Scratch codes, the Scratch project to play, a set of questions, and the link to the Scratch project editor. The user interface runs on the web browser, and the correctness of answers is marked automatically through string matching with the correct answers though it.