Question pretext
Explain to the teacher that, as part of a study with the DOSBSE, we are observing a few classes. Ask the teacher's permission to sit in the back of the class as he or she continues with his or her regular activities.
Make clear that your notes will not be reported back to the school and will not affect his or her career. Therefore encourage him or her to teach as he or she normally would.
Observe the class for 15 minutes, then seek the soonest opportunity to ask the teacher the questions at the end of the questionnaire.