Populations And Samples

Question 1

What is a population?

Answer 1

The whole set of items in interest

Question 2

What does a census do?

Answer 2

Measures or observes every member of a population

Question 3

What is a sample?

Answer 3

A selection of observations taken from a subset of the population which is used to find out information about the population as a whole

Question 4

What is the advantage of a census?

Answer 4

Should give a completely accurate result

Question 5

What are the disadvantages of a census?

Answer 5

. Time consuming
. Cannot be used when the testing process requires destruction of the items
. Hard to process large quantities of data
. Written census’ can be restricted by demand characteristics

Question 6

What are the advantages of using a sample?

Answer 6

. Less time consuming and expensive than a census
. Fewer people have to respond
. Less data to process than a census

Question 7

What are the disadvantages of using a sample?

Answer 7

. The data may not be as accurate
. The sample may not be large enough to give information about small-subgroups of the population, only somewhat accurate as a generalisable result

Question 8

What are sampling units?

Answer 8

Individual units of a population

Question 9

What is a sampling frame?

Answer 9

Sampling units of a population are individually named or numbered to form a list (so the sample can be chosen strategically)