I said in the blog immediately below that I would apologise if my 'sneaking feeling' that an error had crept into a colleague's notes proved to be unfounded. I asked him to clarify what was puzzling me. It transpires that he had made an error - of sorts. A reference to a now defunct idea had stayed in his notes. By way of an oversight, he had not deleted it.
Before I consulted him, I had asked a group of some 70 or so students if they knew anything about this. They did not - despite having reference to it in their lecture notes. Had they not read these notes or had they just memorised them taking what they said at face value without actually studying the topic?
All-in-all the whole affair has proved informative and seems to vindicate my approach: that lecture notes are what students take down in lectures - not what lecturers give in addition to (or, in the case of some students, instead of) lectures.
One cannot learn from notes, when they are the primary source of information. Notes are a distillation and an aide-mémoire to something much fuller; something about which one wants to be reminded in order to give a fuller picture. An edifice cannot be built using only a few straws of information.