After meeting with my team and my team leader today, I went out on the lunch hour and tried all the places I had to leave notices at last time. Got three more places taken care of. Alas, one poor woman locked herself out of her apartment when she answered the door for me. :( But her neighbor (who I also needed to interview - how lucky!) had the landlord's number. AND she could authoratitively tell me that one of my addresses was NOT a residence.
I have an 'appointment' to see another resident at 2 tomorrow. I do hope he's actually there then and answers the door - he indicated he could be a proxy for a vacant apartment in his building, which would be two more down. (Dude! Be there! Please!)
I plan to go out again tonight and try to visit all 11 places I haven't gotten to yet (they are all on the same block).