12/03 Determining Sampling Methods

What is random sampling and why is it important in statistical studies?

• Random sampling is the method of selecting a sample from a larger population in such a way that every individual has an equal chance of being chosen. It is important in statistical studies because it helps to ensure that the sample is representative of the population, which allows for more accurate and reliable results.

• Random sampling is the method of selecting a sample from a larger population based on personal preferences.

• Random sampling is important in statistical studies because it guarantees accurate results without any margin of error.

• Random sampling is the method of selecting a sample from a larger population based on convenience and ease of access.

Explain the difference between simple random sampling and stratified random sampling.

• The main difference between simple random sampling and stratified random sampling is that the former does not involve any division of the population into subgroups, while the latter does.

• Simple random sampling involves selecting every nth individual from the population, while stratified random sampling involves selecting individuals based on specific characteristics.

• Simple random sampling is used for large and diverse populations, while stratified random sampling is used for small and homogenous populations.

• Simple random sampling is more accurate than stratified random sampling in representing the entire population.

How can systematic sampling be used in a statistical study? Provide an example.

• In a statistical study, systematic sampling can be used by selecting every 10th person from a list of customers to gather feedback on a product or service.

• Selecting every 2nd person from a list of employees to gather feedback on a product

• Choosing a random person from a list of customers to gather feedback on a product

• Selecting the first person from a list of students to gather feedback on a service

Discuss the concept of convenience sampling and provide an example of when it might be used.

• An example of convenience sampling is when a researcher selects participants based on their availability for a study.

• Convenience sampling is used when a researcher wants to gather data from a diverse range of participants.

• Convenience sampling is a method used to ensure a representative sample of the population.

• An example of when convenience sampling might be used is when a researcher wants to quickly gather opinions on a new product by surveying people in a shopping mall.

Interview the first 30 students who enter the school in the morning. 

• simple random
• voluntary response
• systematic
• convenience

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected. 

• systematic
• simple random sample
• convenience
• volunteer response

Marianne wanted to know students' opinion on the new schedule at school. She places students' names in a container and randomly picks out 20 names. 

• Convenience Sampling
• Systematic Random Sampling
• Simple Random Sampling
• Volunteer response

Why do we randomly select our samples?

• for control
• reduce bias
• so we don't get the same answers from everyone
• to eliminate confounding results

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.
This is a form of:

• Simple Random Sample
• Stratified Random Sample
• Voluntary Response
• Systematic Random Sampling

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the five closest to her desk.

• simple random
• Voluntary Response
• Convenience
• Systematic Random