Question

Researchers conducted a study to examine the mental health and stress experiences of people living in several communities in a certain region that had experienced highly destructive wildfires. In the methods section of their​ article, the researchers noted​ that: "Random digit dial methodology was used to recruit participants ​(Nequals402​) from residences with a home phone in the three affected cities in the​ region." These are procedures in which phone numbers to call potential participants are randomly generated by a computer. Explain to a person who has never had a course in statistics​ (a) why this method of sampling might be used and​ (b) why it may be a problem if not everyone called agreed to be interviewed.

Answer 1

a) This sampling method is efficient for saving time and eventually it will save the cost of labour. The coverage of this sampling procedure is very high that means one can cover every corner of the city without having any trouble, just by calling potential participants. This sampling method can reach out to the various group of people so the variability of the data is high and the inference we make will be accurate.

b) This sampling method might have some problems:

It may be a case that we have targeted an inappropriate group of people those are not eligible or not interested in the job description.

It also might be a case where we face some under coverage of the data when we are not able to call a potential group of people just because we do not have the contact information or do not have the contact details in telephone directory. Then also everyone called might not agree to be interviewed.

It may also be the case if we do not train our sampling method to be exclusive then repetition of calling to the same participants could have been occurred.