Question

A survey was undertaken to estimate the hours worked per week by volunteers in a social service agency. The agency provides telephone support 7 days a week for 12 hours each day.

There are currently 12,478 volunteers across the country. This number is the number recorded in the volunteer register on 1 May 2018. 100 of these volunteers were randomly chosen. The 100 were each sent an email and asked to record the total hours they worked for the week starting on Monday 7^th May.

In this sample survey, what is the target population that is being sampled? What is the size of the population that is being sampled?

What is the sample unit in this survey? What is the size of the sample?

What is meant by the words “sample frame”? Use this study’s sample frame to explain your answer.

Describe in this study how the sample frame could by mistake include population units that are not in the target population.

Describe in this study how the sample frame could by mistake exclude population units that are in the target population.

Describe how you would randomly select the 100 volunteers for the survey.

What measurement are you taking from each sample unit?

What is the sample estimator in this survey?

Write down four examples of possible non-sampling errors in this survey.

If you were to improve the survey by using stratified random sampling, how would you create separate strata for this population (i.e. what information would you use to stratify the target population)?

Describe what stratified random sampling is and how in this situation it could improve the survey by reducing the variance of the sample estimator.

Answer 1

1. in this sample survey the target population is total volunteers in a social service agency. The total population was of 12,478 volunteers.

2.A single volunteer is a sampling unit here. The sample size is 100 here.

3.sampling frame is the source of things from which you draw the sample. In this study, the samples are being drawn from the total population of volunteers which are working in social service agency. So here the sampling frame is a volunteers that are in the agency.

4. Here the sampling frame consists of all the volunteers in the agency but it may so happen that the volunteer may not be the working volunteer means he/she could be part of board committee members or high level dignitaries or other workers which are not actually working on the telephone support or volunteers who were absent in full week from 7th may (monday) .

5.The volunteers which have joined after 1 May 2018 will be excluded from the target population

6.We will randomly assign one number against the list of volunteers. Then by taking random numbers we will select the volunteers who will get the number which will be taken from random number.

7. The measurements taken was he total hours they worked for the week starting on Monday 7^th May.

8.The sample estimator would be the mean of the 100 samples taken.