Extension: Do you think it matters who is used in psychology research? Explain. Discuss how you think that researchers find/gather participants for research.

* Sampling

By the end of this lesson you will be able: * To describe what is meant by the following: Opportunity sampling, random sampling, systematic sampling, stratified sampling, volunteer sampling, target population, sample population * To evaluate sampling techniques.

* Your sample Q. If they wanted to conduct interviews to find out student views on life in the sixth form at our school, why might researchers decide not to interview every student? A: It takes too much time to interview every student, so we would normally take a representative sample of the target population by using a sampling method.

* Target population Discuss: What do you think is meant by this term? Definition: a group of people who share a certain set of characteristics that the researcher is interested in studying. General Population Target population Sample

* Sampling techniques Use your textbook to read about the five sampling methods a researcher might use. Put an example of each in your booklet. Researchers make generalisations about the target population from the sample as long as the sample is representative of the target population. All sampling methods aim to produce a representative sample, but they are inevitably biased. Extension: Which sampling method do you think has the most/least bias and why?

* A sample of the target population in which some members of the population are less likely to be included than others.samplepopulation * E.g. Your target population is year old students in Essex. Your sample (participants used) are 40 females aged 16 from Clacton and 10 males aged 18 from Southend. * Why could this sample be seen as bias? Explain the potential for bias in the five sampling methods we have looked at in your booklet. I.e. is it high/low and why.

* The extent to which the results from the sample used can be applied to the target population as a whole. * E.g. Your target population is nurses who work at Basildon hospital. You carry out your research on nurses who are working a weekend night shift. * Why would it be difficult to generalise any results to the target population? Explain the potential to generalise from each sampling method we have looked at in your booklet. I.e. is it high/low and why.

* Which sampling technique has the highest population validity? * Based on this, discuss the following: 1) Why do researchers still use opportunity and volunteer sampling despite the potential for bias and limited generalisability? 2) Why don’t researchers use random sampling more often? Extension: What social group do you think the majority of participants used are made up of? Why?

1) Imagine you are carrying out a questionnaire to investigate whether first time mothers with babies under 1 year are showing any signs of depression and/or anxiety. * Explain how you could use each of the different sampling methods to gather a sample of participants from the target population. * For each example of sampling you give state how this would affect the bias and generalisability of your results to the target population in this study. Extension: Read through the Banyard and Hunt article.

* Exam question ‘ Some psychology students read about an experiment which suggested that organisation is a useful strategy for improving memory. The students carried out an experiment to investigate the effects of organisation on word recall. They made up a list of 50 items that could be bought in a supermarket. The participants were teachers at their school. One group of participants saw the words organised in categories such as fruit, vegetables, dairy products and cleaning materials. The other group saw the same words presented randomly.’ 1a) The students decided to use a volunteer sample. Suggest one way in which this sample could be obtained. (2 marks) 1b) The students decided to use a random sample. Suggest one way in which this sample could be obtained. (2 marks) Extension: Explain how they could have used an opportunity sample.

You are now able: * To describe what is meant by the following: Opportunity sampling, random sampling, systematic sampling, stratified sampling, volunteer sampling, target population, sample population * To evaluate sampling techniques.

Deadline already set: 1) Continue to work on your Assessment one. Preparation for next lesson: Read through the section on hypotheses in your textbook.