Chapter 1.1

Census

it observes or measures every member of a population

Population

the whole set of items that are of interest

Sample

Observations taken from a subset of a population which is used to find out info about the entire population

Sampling units

individual units of a population

advantage of a census

completely accurate results are given

disadvantage of a census

time consuming, expensive, hard to process large quantities of data, can’t be used if the testing destroys the item.

sampling frame

a list of individuals from which the sample is drawn

advantage of a sample

less time consuming. cheaper. fewer people have to respond. less data to process.

disadvantage of a census

the data may not be accurate. sample may not be large enough to give info about small populations.

how can the size of the sample affect the validity of any conclusions?

it depends on the accuracy and the amount of resources.