  Introducing computational thinking in primary school curricula implies that
teachers have to prepare appropriate lesson material. Typically this includes
creating programming tasks, which may overwhelm primary school teachers with
lacking programming subject knowledge. Inadequate resulting example code may
negatively affect learning, and students might adopt bad programming habits or
misconceptions. To avoid this problem, automated program analysis tools have
the potential to help scaffolding task creation processes. For example, static
program analysis tools can automatically detect both good and bad code
patterns, and provide hints on improving the code. To explore how teachers
generally proceed when creating programming tasks, whether tool support can
help, and how it is perceived by teachers, we performed a pre-study with 26 and
a main study with 59 teachers in training and the LitterBox static analysis
tool for Scratch. We find that teachers in training (1) often start with
brainstorming thematic ideas rather than setting learning objectives, (2) write
code before the task text, (3) give more hints in their task texts and create
fewer bugs when supported by LitterBox, and (4) mention both positive aspects
of the tool and suggestions for improvement. These findings provide an improved
understanding of how to inform teacher training with respect to support needed
by teachers when creating programming tasks.
