Sampling Methods and Bias Concepts

The video tutorial explains the concepts of population and sample, highlighting the importance of unbiased sampling methods. It covers biased sampling methods like convenience and voluntary response samples, and unbiased methods such as simple random sampling (SRS), stratified random sampling, and multi-stage sampling. The tutorial also introduces the use of a random digits table for random selection in sampling.

What is a convenience sample?

• A sample that is randomly selected

• A sample that includes people who volunteer

• A sample that includes people who are easy to reach

• A sample that includes everyone in the population

Why is a voluntary response sample considered biased?

• Because it includes people who are easy to reach

• Because it includes people who have a strong interest in the topic

• Because it is randomly selected

• Because it includes everyone in the population

What is an unbiased sample?

• A sample that includes volunteers

• A sample that is chosen by the researcher

• A sample that gives each member of the population an equal chance of being chosen

• A sample that includes only a specific group

How is a simple random sample (SRS) typically conducted?

• By putting names into a hat and selecting randomly

• By dividing the population into groups

• By selecting people who are easy to reach

• By allowing people to volunteer

What is the purpose of dividing a population into strata in stratified random sampling?

• To exclude certain groups from the sample

• To randomly select individuals

• To ensure each group is represented in the sample

• To make the sampling process easier

How does stratified random sampling ensure representation?

• By excluding certain groups

• By choosing the largest group

• By randomly selecting from each stratum

• By selecting only volunteers

In multi-stage sampling, what is the first stage typically involved?

• Selecting individuals randomly

• Dividing the population into strata

• Choosing which group to sample using an SRS

• Allowing people to volunteer

What is the function of a random digits table in sampling?

• To randomly select individuals for a sample

• To organize the population into groups

• To allow people to volunteer for the sample

• To ensure the sample is biased

Why might a number be ignored when using a random digits table?

• Because it is the first number

• Because it is a duplicate

• Because it is not a random number

• Because it is too large for the sample size

What is the main advantage of using multi-stage sampling?

• It is the simplest method

• It allows for a more detailed selection process

• It requires no random selection

• It is the fastest method