There's nothing like reinventing the wheel to make one feel foolish. On the other hand, to independently hit on an idea should be a sign of intelligence. I am referring to my previous blog when I realised that in order to get responses to all the questions in my research questionnaire, I should divide it into two (or three, or four) separate questionnaires and give each person one of those questionnaires.
I have discovered that this technique is called 'split questionnaire design' and there are plenty of papers available on Google Scholar which discuss it. Most of them seem very heavy on the statistics, which is something that I can leave for my supervisor. I found one interesting paper (by Adigüzel and Wedel) entitled "split questionnaire design for massive surveys", which seems to contain everything that I need.
I notice that the abstract finishes "... as a result of reduced respondent burden, the quality of data using split questionnaire design improves". Amen.