Statistics Sampling Methods & Survey Design 1 — Questions and Answers
Question 1: Which sampling method assigns each member of the population a unique number and selects individuals using a random number generator?
- Stratified sampling
- Simple random sampling (Correct answer)
- Cluster sampling
- Systematic sampling
Correct answer: Simple random sampling
Simple random sampling gives every member of the population an equal chance of selection by using random number generation or a random number table.
Question 2: In systematic sampling, a researcher has a population of 800 and wants a sample of 40. What is the correct sampling interval?
- 10
- 40
- 20 (Correct answer)
- 80
Correct answer: 20
The sampling interval is calculated by dividing the population size by the desired sample size: 800 ÷ 40 = 20.
Question 3: A researcher divides a population by income level and gender, then randomly selects individuals from each group. This technique is known as:
- Cluster sampling
- Convenience sampling
- Stratified sampling (Correct answer)
- Multistage sampling
Correct answer: Stratified sampling
Stratified sampling divides the population into homogeneous subgroups (strata) and then randomly samples from each stratum.
Question 4: Which sampling method selects naturally occurring groups as the sampling unit rather than selecting individuals directly?
- Simple random sampling
- Systematic sampling
- Stratified sampling
- Cluster sampling (Correct answer)
Correct answer: Cluster sampling
Cluster sampling selects entire pre-existing groups (clusters) such as classrooms or zip codes, then surveys all or a sample of members within those clusters.
Question 5: Which sampling approach is most susceptible to producing a biased, non-representative sample?
- Simple random sampling
- Proportional stratified sampling
- Convenience sampling (Correct answer)
- Systematic sampling
Correct answer: Convenience sampling
Convenience sampling selects individuals who are easiest to reach, which typically results in a sample that does not represent the broader population.
Question 6: The complete list of all individuals or units from which a sample will be drawn is called the:
- Population parameter
- Sampling frame (Correct answer)
- Survey instrument
- Confidence interval
Correct answer: Sampling frame
The sampling frame is the specific list or database of all members of the target population from which a sample is selected.
Question 7: In proportional stratified sampling, how is the number of individuals selected from each stratum determined?
- Each stratum contributes an equal number regardless of size
- Based on the researcher's personal judgment
- In proportion to the stratum's relative size in the population (Correct answer)
- By selecting only from the largest strata
Correct answer: In proportion to the stratum's relative size in the population
Proportional stratified sampling allocates sample units from each stratum based on that stratum's proportion of the total population, ensuring representative coverage.
Statistics Sampling Methods & Survey Design 1
Which sampling method assigns each member of the population a unique number and selects individuals using a random number generator?