Question

A recent study followed 900,000 US Kids from 1982 to 1998. At baseline, all participants were screened and determined to be cancer free and their body mass index (BMI) was calculated. Body mass index is a measure of obesity that is calculated using a person’s height and weight. Subjects were separated into the following groups according to their BMI: (a) normal weight, (b) slightly overweight, (c) moderately overweight and (d) greatly overweight. 57,145 deaths from cancer occurred in the population during the follow-up period.  

This study used self-administered mail questionnaires to gather data on height and weight in order to calculate the measure of obesity. Which type of bias was avoided because of this approach?

	a	Recall bias.
	b	Selection bias.
	c	Interviewer bias.
	d	Response bias.

Answer 1

Answer ; d) response bias.

Reason ; In the given scenario, the data are collected from the targeted sample of people from 1982 to 1998. Here the researcher is using self report method of data collection in his process and this can be carried out through E-mail. There are so many chances to make mistake while responding to the researcher question. From the given scenario, there is nothing wrong with the researcher part, but the population sample will have a chance to make a mistake while submitting their response. hence the above mentioned type of bias is applicable for the given situation and the other types of bias are not relevant.