A tracer for teacher development in the programming language ScratchJr

Abstract

Block-based languages have features that make leaning programming easier. Future teachers should have basic competences in informatics and programming, similarly to their competences in other subjects. These competences should comprise concepts and skills of programming, including program debugging. However, programming environments for block-based languages do not include affordances to control program execution. In this paper, a program tracer for the ScratchJr language is presented, implemented as an extension of its programming environment. The main facilities included are: to display the values of sprite attributes, the inclusion of several ways of controlling the advance of program execution, to display the number of the iteration being executed in counter loop, and to display simultaneously the scripts of all the characters.