Question

Telephone directories are notorious for being inadequate sampling frames. Suppose the population was defined as “all telephone subscribers in the directory’s service area.” What criticisms could you make of the telephone directory as a sampling frame?

Answer 1

1. There are a lot of families who either don't opt for telephone service or have a transient nature of job, etc, and so such families get left out from the sampling.

2. Also, many households do not want to be in the telephone directory, hence opt out voluntary. The sample gets biased further as it missed such households.

3. Another problem could be the age of the directory. If the population of a region, for example, shot up recently and one is using an older telephone directory, the sampling could not be representative of the current population.

4. A single household can have Multiple telephone lines, which increases the probability of such households to be included in the sample. Hence, the sample gets biased.