Your chance of getting a good, or even just OK, teacher is about 20/80.

After having attended a number of courses, I strongly suspect that they do not require any kind of teaching background or experience from their “teachers”. In the eight years I have lived in Berlin, I have come across one (1) teacher who very clearly had teaching background and also had obviously received formal training in the subject at hand. The rest – not so much – in fact many of them have shown a glaring lack of any kind of teaching capabilities, let alone formal training in the subject in which they were supposed to teach, and in many situations acted extremely unprofessionally.

For an institution which has the word “school” in their name, and whose courses are, for many, not particularly cheap – AND heavily government subsidised – that is quite remarkable. And perhaps the reason why they don’t have any kind of post-course evaluation procedure in place.