This is where I have a problem with a non-specialist observing. As a mathematician, it would be relatively straightforward to convince a non-mathematician of what work was being done. In a similar way to me observing a class of children reading a book for English. There are many interpretations of the event. Is the teacher just coasting - and is this a common occurence - or is this a normal part of English language teaching? I dare say one could be convinced of either depending upon ones raison d'etre for being there. I quite like DM's idea of paired observations. We do this for interviews on occasion, but seldom for teacher observations.