data collection

What is a population in research?

The entire collection of individuals being studied.

Define population parameter.

A value describing the population.

What is a census?

Data collected from the whole population.

Why is a census not ideal for large populations?

Because it is not very practical for large or evolving populations.

What is a sample?

A subset of a population being studied.

What is the goal of sampling?

To be as representative as possible of the population.

What is a sample statistic?

A value describing the sample of a population.

How can a statistic be useful?

If it is accurate enough, it can be generalized to the population.

What is simple random sampling?

A method where every individual and combination has an equal chance of being selected.

What is stratified sampling?

A method where a population is grouped into strata, and a simple random sample is taken from each strata.

What is cluster sampling?

A method where a population is grouped into clusters, and a census is taken from selected clusters.

What is systematic sampling?

A method where individuals are selected according to a system.

What is convenience sampling?

A method where individuals are hand-selected.

What is voluntary sampling?

A method where individuals are prompted to respond.

What is an observational study?

A research method that doesn’t use treatments.

What are the two types of observational studies?

Retrospective (collecting present/past data) and prospective (collecting future data).

What is a key limitation of observational studies?

They cannot determine a causal relationship.

What is the main feature of experiments?

They use treatments and can determine a causal relationship.

What is undercoverage bias?

An error in sampling method where a population group is not represented in the sample.

What causes response bias?

Alteration to a group’s response, such as framing or incentives.

What is non-response bias?

Caused by a sample group’s decision not to respond.