From 1983 to 1989, we ran a weekly TV survey in Adelaide. Every Saturday, an interviewer would go to a randomly selected area and leave questionnaires at ten households, one for each person aged 10 or above. The people filled in their questionnaires over the next 24 hours, and the interviewer came back to collect the completd questionnaires on Sunday - or leave a business reply envelope for any questionnaires not yet completed.
The work was verified by mailing out check letters to a few household in each cluster. This letter repeated a few key questions, and added several others such as "was the interviewer courteous?"
This was a cheap way to do a survey, and it all ran very smoothly. A lot of our interviewers were young people, often students. One of them was a very self-possessed young woman, pleasant but rather dominating. She was big, too: both tall and solid
For the first few weekends she worked, our field supervisor went out with her, checking her work. It seemed fine, so after that we just sent out check letters each week.
We always got a very good response rate from her work - I suspected that she terrified respondents into submission. Let's call her Volumnia. The interviewers seldom came into the office - we used mail and couriers to send out the blank questionnaires and collect the completed ones.
One day we had a visit from a guy we'd never seen before. He was Volumnia's brother, he said. Let's call him Tim. She'd run out of business reply envelopes, and he was just passing by our office, and she'd asked him to collect some for him. He stammered a little, obviously nervous.
That was exactly the sort of thing Volumnia would do, we said to each other in the office: to send her little brother on an errand for her.
Every now and again, on top of the random checks by mail, our supervisors would revisit some surveyed households, and do an in-person check. After some months, we did one of these checks in an area Volumnia had surveyed.
"Was the interviewer courteous and well-mannered?" the supervisor asked.
"Sure!" said the householder. "He was very polite indeed."
The householder described the interviewer: a friendly young man, with a bit of a stammer.
We investigated further, rechecking months of Volumnia's work. Every respondent agreed that the interviewer had been a very pleasant young man.
We were about to confront Volumnia and asked her what was going on, when Tim called in at the office again, to pick up some more envelopes for his sister. We confronted him instead, and he was seized by an outbreak of stammering.
We didn't have to interrogate him much, before he confessed. His sister had only ever worked those first two weekends, he admitted. On the third weekend, she had an important appointment, and asked Tim to do the work for her. She'd given him our instruction manual, which he'd studied carefully before going out to knock on doors and leave questionnaires. Each weekend after that, Volumnia had had urgent and important things to do, and had kept asking Tim to do the work for her. She even allowed him to keep some of her pay.
"What about the interviewer ID card with the photo?" we asked Tim.
"Hardly anybody asks, but if they do I j..j..just tell them I'm doing the work for my sister."
So we changed our records, and officially signed up Tim. Volumnia was upset that her pay cheques stopped arriving, but I heard that Tim always gave her a solid percentage. After all, she'd found the job for him.