Question

A statistics student at a small liberal arts college who is curious about the relationship between the amount of time students at his college spend on social networking sites and their performance at school decides to conduct a survey. Four research strategies for collecting data are described below. In each, name the sampling method proposed and any bias you might expect. Strategy 1: He obtains a list of the 1500 students at the college. He chooses a random number k between 1 and 15 and then samples that person and every kth person on the list. He emails the survey to each of the people in the sample and asks them to complete it by next Friday

1. What is the sampling method?
A. Simple random sampling
B. Convenience sampling
C. Cluster sampling
D. Systematic sampling
E. Stratified sampling
2. What type of bias would you expect? (check all that apply)
A. No bias in this survey
B. Response bias
C. Selection bias
D. Nonresponse bias Strategy
2: He gives out the survey only to his friends, and makes sure each one of them fills out the survey
3. What is the sampling method?
A. Simple random sampling
B. Convenience sampling
C. Cluster sampling
D. Systematic sampling
E. Stratified sampling
4. What type of bias would you expect? (check all that apply)
A. Selection bias
B. Nonresponse bias
C. No bias in this survey
D. Response bias Strategy
3: He randomly chooses 3 floors of the largest dorm on campus and distributes a paper survey to each resident on those floors. He places a box in the common room of the dorm to collect the completed surveys
5. What is the sampling m ethod?
A. Stratified sampling
B. Cluster sampling
C. Simple random sampling
D. Convenience sampling
E. Systematic sampling
6. What type of bias would you expect? (check all that apply)
A. Response bias
B. Nonresponse bias
C. No bias in this survey
D. Selection blas
7. Which strategy will give him the most representative sample of students at his college?
A. Strategy 1
B. Strategy 2
C. Strategy 3

Answer 1

Strategy 1:

I) D: Systematic Sampling

II) D: non - response bias.

Strategy 2:

I) B: Convenience Sampling

II) A: Selective bias

Strategy 3:

I) B: Cluster Sampling

II) B: non - response bias.

7) A: Strategy 1

Explanation:

For Strategy 1,

I) the sampling method is systematic sampling. This is because Systematic sampling is a kind of method for probability sampling whereby sample members from a larger population will be selected according to a random starting point but it will be for a fixed or periodic interval.

Now, we were told that he chooses a random number k between 1 and 15 and then samples that person and every kth person on the list. This corresponds to a random starting point as shown in systematic sampling above.

We are also told that he emails the survey to each of the people in the sample and asks them to complete it by next Friday. This corresponds to a fixed time interval in the definition too. Thus, it is proven to be systematic sampling.

II) The bias here will be Nonresponse bias Strategy. This is because all the students may not respond to the survey as it is possible that the students may forget to fill the survey or may ignore it or may be too busy to reply. Thus, it is a non - response bias.

For Strategy 2: He gives out the survey only to his friends, and makes sure each one of them fills out the survey

I) The sampling method here is convenience sampling which can be defined as a sampling method where the sampling units are selected in line with how convenient it is for the researcher. In this case he has given it to only his friends and made sure they filled. Which means he did it with a convenience bias.

II) Because he gave it to only his friends, he may not have a true reflection of the research as it was inky his friends instead of being random where he can have diverse views that can truly represent the population. Thus, it is a selection bias.

For strategy 3;He randomly chooses 3 floors of the largest dorm on campus and distributes a paper survey to each resident on those floors. He places a box in the common room of the dorm to collect the completed surveys.

I) The type of sampling used here is cluster sampling which is defined as a sampling method where the population is divided into clusters and random sample picked from each cluster. In this case, the population has been divided into 3 floors and he randomly distributed to residents on each of those floors. Thus, it is an example of Cluster sampling

II) The bias here will be non - response bias because the could choose not to respond to the paper survey for various reasons and thus not all will respond. This leads to a non - response bias.

7) Strategy 1 will give the most representative sample of students at his college because he selected from the entire list of 1500 students.