Observing without disturbing the observed
by Phil Bartle, PhD
Unobtrusive measures are those that do not intrude on the subjects
If you study people from the telephone book, for example, they will not know that they are being studied.
If you sit on a bus and observe where people tend to sit, they are unlikely to know that they are being observed.
The problem with many unobtrusive measures is that they, too, are unlikely to reveal much valid or meaningful in-depth material.
Living with people, as in participant observation, is a possibility of being unobtrusive, so long as you do not tell your subjects that you are there as a scientist to study them.
This raises an ethical question about observing people without their knowledge.
As with taking a formal photograph, if they know you are there to study them, they will pose for you.
At some point, however, you may want to supplement your observations with some in-depth questions.
Again, this may be done with or without telling them they are being studied.
If they trust you, they are less likely to hide information from you, and perhaps less likely to give you answers that they think you want to hear.
It is a bit like the problem faced in nuclear chemistry or physics.
If you determine the location of an electron, you modify its velocity, or if you determine its velocity, you modify its location.
The very act of observation (if you want great accuracy) itself results in the subject modifying its behaviour.
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