Correlations and Distributions

Question 1

What is correlation(al study)?

Answer 1

1. Correlation is a measure of the relationship between two variables,
2. In a correlational study data is collected for some kind of correlational analysis.

Question 2

Advantages of correlational research?

Answer 2

1. Doesn’t involve controlling any variables, you can do it when you couldn’t do a controlled experiment, whether for ethical or pratical reasons,
2. I.e., An experiment into the effects of smoking on humans probably wouldn’t be done for ethical reasons, but a correlation between smoking and cancer could be established from hospital records,
3. Correlational analysis can give ideas for future research,
4. Correlation can even be used to test for reliability and validity.

Question 3

Limitations of correlational research?

Answer 3

1. Correlational analysis can’t establish ‘cause and effect’ relationships - it can only show that there is a statistical link between two variables. Variables can be closely correlated without changes in one causing changes in the other; correlation does not equal causation,
2. Care must be taken when interpreting correlation coefficients - high correlation coefficients could be down to chance. To decide whether a coefficient is significant, you have to use a proper significance test