The term Computational Thinking (CT) is commonly acceptable as a 21st century skill in reading, writing, and arithmetic, causing many states to adopt new policies as far as the curriculum, didactic material, teaching and learning methods, as well as assessment methods. In this frame, we have developed a series of Arduino lessons for teachers’ training, including physics computing and computational thinking development. For the training material quality improvement, we have developed a set of assessment criteria (Rubric) that will be used during the teacher’s training course resulting in the formative assessment. The aim of this work is to analyze and justify the rubric’s format and priorities, as well as to inform the teachers’ trainers about the course assessing priorities.