Research methods and statistics. Learning outcomes At the end of this session and with additional reading you will be able to: Critically evaluate a.

Research methods and statistics

Learning outcomes

At the end of this session and with additional reading you will be able to: Critically evaluate a research paper

Internal validity is concerned about the causal-effect relationship in a study◦ Can observed changes be attributed to your

programme/intervention or are the results influenced by alternative causes?

Three types of threat:◦ Single groups◦ Multiple groups◦ Social interactions

History – some historical event that occurred Maturation – events over time that aid

learning Testing – pre-testing primes the participants

for what is to come (practice effect) Instrumentation – is there any difference in

the pre-test/post-test instrument Mortality – have any participants dropped out Regression- pre-test scores are always likely

to improve on a post-test

Have a control group that does not have the programme/intervention◦ Placebo effect in medical trials

Selection bias – the degree to which the groups are comparable before the study◦ Selection history threat◦ Selection testing threat◦ Selection maturation threat◦ Selection instrumentation threat◦ Selection mortality threat◦ Selection regression threat

Conduct a randomised or true experiment

Diffusion of treatment – participants share their experiences with other participants

Compensatory rivalry – groups try and compete with one another

Resentful demoralisation - the comparison group under achieves due to jealousy with the other group

Compensatory equalization of treatment - the researcher tries to make one or both groups feel special

External validity is concerned with generalisation◦ Can you generalise your results to a wider

population Sample modelling – you first identify the

population you want to generalise to and then draw a sample from that population

Proximal similarity (Gradient of similarity) – identify populations that are more or less similar to the original study

Unusual people Unusual places Unusual times

Use a random sample Keep drop out rates low Replicate the study with different people at

different times in different places

Electronic resources are available from◦ http://www.socialresearchmethods.net/kb/contents.php