Sampling refers to a group of people taking part in a market research survey selected to be representative of the target market overall

Types of sampling› Random› Quota› Stratified› Cluster› Snowballing

Sampling errors refer to errors in research caused by using a sample for data collection rather than the whole target population

Each member of the population has an equal chance of being included in the sample

Everyone has an equal chance – this might reduce bias

Quite easy

Could select people who are not part of target group

May not get representative results

Each Population is segmented into mutually exclusive sub-groups (e.g. male/female). From these groups, a certain number of people are selected to part of the sample

Sample can be obtained quickly and cheaply More reliable than random sampling

Not always representative of the population Sampling errors could occur because not

everyone has an equal chance to be sampled

Involves segmentation (segments = strata). Participants are chosen from each group but in a way that is proportional to the population

Samples are more representative of target market

Can be difficult to select strata

If the population is too far spread, market researchers will sample indiviudal groups, known as clusters. i.e. from just a few lcoations

Quick and easy, relatively cheap

Bias and sampling errors (sometimes people living in same area share similar views/characteristics)

May not get representative results

The first respondent refers a friend…who then refers another friend…who then refers another friend…etc

Cheap Easy to get contact details of

respondents

Tends to be very biased

As with all things, there are limitations to sampling. The main drawback of sampling is errors. We can categorize these errors into non-sampling errors and sampling errors.

› Differentiate between the two types of errors

› Explain why sampling errors could occur