Sampling Methods and Bias Analysis

The video discusses nonprobability sampling methods, which lack randomness and can introduce bias. It covers convenience sampling, snowball sampling, purposive sampling, and voluntary sampling, highlighting their potential issues such as confounding variables and selection bias. The video contrasts these with probability sampling, emphasizing the importance of randomness in reducing bias.

What is a key characteristic of nonprobability sampling?

• It lacks a random element in participant selection.

• It is always more accurate than probability sampling.

• It ensures equal representation of all groups.

• It involves a random selection process.

Which of the following is a potential issue with convenience sampling?

• It may introduce unrecognized confounding factors.

• It requires a large sample size.

• It is too expensive to conduct.

• It is too time-consuming.

In snowball sampling, how are new participants typically recruited?

• Through online advertisements.

• By referral from existing participants.

• By the researcher’s judgment.

• Through random selection.

What is a major drawback of snowball sampling?

• It is difficult to find initial participants.

• It requires a lot of time to implement.

• It is too costly.

• Participants are often socially connected, leading to bias.

What is another name for purposive sampling?

• Systematic sampling

• Judgmental sampling

• Accidental sampling

• Random sampling

In purposive sampling, who decides which participants are included?

• The participants themselves

• A random number generator

• The researcher

• A computer algorithm

What is a common reason people volunteer for voluntary sampling?

• They are randomly selected.

• They are paid to participate.

• They are required by law.

• They have a personal interest or motivation.

What is a shared issue among all nonprobability sampling methods?

• They all require a large sample size.

• They all lack randomness, leading to potential bias.

• They all involve random selection.

• They are all very expensive.

Why might nonprobability sampling lead to bias?

• Because it is too time-consuming.

• Because it always uses a small sample size.

• Because it involves random selection.

• Because it often includes similar participants due to non-random selection.

Which sampling method involves participants self-selecting to be part of the study?

• Convenience sampling

• Snowball sampling

• Purposive sampling

• Voluntary sampling