Unit 3.3 Market Research

A set which includes all measurements of interest to the researcher

• Sample

• Population

• Error

• Other

The collection of all responses, measurements, or counts that are of interest

• Sample

• Population

• Error

• Other

A subset of the population

• Sample

• Target

• Error

• Other

Why sampling?

• Less costs

• Less field time

• More accuracy

• When it’s impossible to study the whole population

The population to be studied/ to which the investigator wants to generalize his results

• Sampling unit

• Target Population

• Sampling frame

• Sampling scheme

Smallest unit from which sample can be selected

• Sampling unit

• Target Population

• Sampling frame

• Sampling Scheme

List of all the sampling units from which sample is drawn

• Sampling unit

• Target Population

• Sampling frame

• Sampling Scheme

Method of selecting sampling units from sampling frame

• Sampling unit

• Target population

• Sampling frame

• Sampling scheme

Sample is selected from elements of a population that are easily accessible

• Snowball sampling

• Purposive sampling

• Convenience samples

• Quota sample

Non probability samples

• Probability of being chosen is unknown

• Cheaper

• Unable to generalise

• Potential for bias