Research Methods 2

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Topic 4: Populations, samples and inference (Week 4)

Aims

To introduce the idea of a population and its parameters, a sample from the population and how to use a sample to make inferences about the population.

Objectives

To be able to explain the distinction between a sample and a population and between parameters and statistics.

To be able to explain, in general terms, what a Normal distribution is and what are its defining parameters. To use sample statistics to obtain estimates of the corresponding population parameters.

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The first part of the work this week introduces the idea of population and sample.

• Study the document Populations and Parameters, which explains the idea behind a population, what is meant by its parameters and a sample drawn from the population.
• Answer the questions in Exercise Sheet 1.
• You should check your answers by referring to the Solutions to Exercise Sheet 1.

When you have done this you can consider how to use sample statistics to estimate population parameters.

• Study the document Samples and Statistics.
• Answer the questions in Exercise Sheet 2.
• Again, check your answers, using Solutions to Exercise Sheet 2.

Further reading on the topics addressed this week can be found in Bland, sections 3.1-3.5, 7.1-7.4 & parts of 6.1-6.5.