A Question from a collegue
Dave Roberts
Someone did the following survey:
- Population = 600
- Surveyed = 600 (ie. non-random)
- Question posed is binary: happy - yes or no
- Return: 225 answered, 80% yes, 20% no
One should be able to calculate the deviation on a random survey. How
about a non-random one with a serious non-response bias like the above
example? What deviation should be used? Can it be calculated? These
kinds of surveys are common in the corporate world but I always raise
the issue of it being non-random and having serious non-response. Now
I'd like some expert feedback and some numbers.
smw
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| Dave Roberts - OOUIs R US |
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Robert E George
One approach on how to conduct these surveys is to not permit
'nonresponse' while still preserving privacy:
Interview the respondents face-to-face. Ask them to think of
a number between 1 and 10. Then say,
"If the number is even, answer the question 'Are you happy?'.
If the number is odd, just say 'No'"
Robert George
The OSU Statistics Department
(speaking only for myself)
Michael Kubovy
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| One approach on how to conduct these surveys is to not permit
| 'nonresponse' while still preserving privacy:
| Interview the respondents face-to-face. Ask them to
| think of a number between 1 and 10. Then say,
| "If the number is even, answer the question 'Are you happy?'.
| If the number is odd, just say 'No'"
The problem with this approach is that about 29% of people think of
'7' and 11% think of '3'. (See Kubovy, M., & Psotka, J. (1976). The
predominance of seven and the apparent spontaneity of numerical
choices. Journal of Experimental Psychology: Human Perception &
Performance, 2, 291-294.) Better use the last digit of the
respondent's social security number.
--
|\ /| / MICHAEL KUBOVY (kub...@virginia.edu)
| \/ |/ OFFICE: 804-982-4729; LAB: 982-4751; FAX: 982-4766
| |\ Department of Psychology, Gilmer Hall,
| | \ Univ. of Virginia, Charlottesville, VA 22903-2477