Reliability and Validity

• Refers to the consistency of measurement

• If a research method has reliability, it could be used again under the same conditions with the same subjects and you would expect to obtain similar result.

• Refers to the measurement that accurately reflects what it is intended to measure.

• For example, a research study that requires 15 year olds to complete a questionnaire based on what they have eaten for the past three days may be valid, as most 15 year olds would be able to accurately recall what they have eaten and complete written answers. In contrast, carrying out this research with four year olds would not be valid, as most four years old would neither be able to accurately recall what they have eaten nor complete a written response.

• Validity within your IRP can be assured by having:

  • • Completed sufficient reading of secondary data so that you are reasonably knowledgeable on your topic and will therefore not rely on biased judgements.

    • A good understanding of the research methods

    • More than one research method in your data collection

Note: See Accuracy vs Validity vs Reliability.

• The sample methods need to be specific to the project - If it is a sensitive topic random sampling would be best in order that they openly discuss their opinions.

• The sample group needs to reflect the population being researched.

• The sample size needs to be of significant value (usually the larger the better).

1. Outline the importance of sampling for reliable research (3 marks)

2. Describe the Purpose of Research, using an example to support your answer (3 marks).