Coding and computational thinking have recently become compulsory skills in many school systems globally. Teaching these new skills presents a challenge for many teachers. A notable example of professional development designed using Constructionist principles to address this challenge is ScratchEd. Upon reflecting on her experiences designing and running ScratchEd, Karen Brennan identified five tensions faced by professional development providers, and proposed that these tensions could be used for scrutinising and critiquing professional development. In this paper we analyse, through the lens of Brennan's tensions, the process we have followed to design, evaluate and improve professional development. We argue that while we have experienced the same tensions, the extent to which we assess learning is a new tension that extends those identified by Brennan. There are strong reasons to assess teachers' knowledge, however, quantitative measures of learning could be at odds with Constructionism: as Papert argued in Mindstorms, constructionist educators should study their learning environments as anthropologists. Consequently, we have called this new tension the tension between anthropology and assessment.
In this article we report about a study to assess Dutch teachers' Pedagogical Content Knowledge (\small PCK), with special focus on programming as a topic in secondary school Informatics education. For this research, we developed an online research instrument: the Online Teacher \small PCK Analyser (OTPA). The results show that Dutch teachers' \small PCK scores between low and medium. Also we enquired whether there is any relation between teachers' \small PCK and the textbooks they use by comparing the results of this study with those of a previous one in which the \small PCK of textbooks was assessed. The results show that there is no strong relation. Finally, we looked for trends between teachers' \small PCK and their educational backgrounds, as most of the Dutch teachers have a different background than Informatics. The results show that also in this case there is no strong relation.
The goal of this literature study is to give some preliminary answers to the questions that aim to uncover the Pedagogical Content Knowledge (PCK) of Informatics Education, with focus on Programming. PCK has been defined as the knowledge that allows teachers to transform their knowledge of the subject into something accessible for their students. The core questions to uncover this knowledge are: what are the reasons to teach programming; what are the concepts we need to teach programming; what are the most common difficulties/misconceptions students encounter while learning to program; and how to teach this topic. Some of the answers found are, respectively: enhancing students' problem solving skills; programming knowledge and programming strategies; general problems of orientation; and possible ideal chains for learning computer programming. Because answers to the four questions are in a way not connected with each other, PCK being an unexplored field in Informatics Education, we need research based efforts to study this field.