SOC 13 - Correlations

Question 1

What is correlation?

Answer 1

A mathematical technique in which a researcher investigates an association between two variables/co-variables

Question 2

What are co-variables?

Answer 2

• The variables investigated within a correlation, for example height and weight
• They are not referred to as independent and dependent variables because a correlation investigates the association between variables, rather than trying to show a cause-and-effect relationship

Question 3

What is a correlation coeffecient and what is the scale?

Answer 3

It shows the strength of a correlation with a value between -1 and 1

• between 1 and 0.8 => very strong positive correlation
• between 0.8 and 0.6 => strong positive correlation
• between 0.6 and 0.4 => moderate positive correlation
• between 0.4 and 0.2 => weak positive correlation
• beteen 0.2 and -0.2 => negligible or no correlation
• between -0.2 and -0.4 => weak negative correlation
• between -0.4 and -0.6 => moderate negative correlation
• between -0.6 and -0.8 => strong negative correlation
• between -0.8 and -1 => very strong negative correlation

Question 4

What is a positive correlation?

Answer 4

As one co-variable increases so does the other

Question 5

What is a negative correlation?

Answer 5

As one covariable increases the other decreases

Question 6

What is a zero correlation?

Answer 6

When there is no relationship between the co-variables

Question 7

What is the difference between correlations and experiments?

Answer 7

• In an experiment the researcher controls or manipulates the independent variable in order to measure the effect on the dependent variable. As a result of this deliberate change in one variable it is possible to infer that the IV caused any observed changed in the DV
• In a correlation, there is no such manipulation of one variable and therefore it is it not possible to establish cause and effect between on co-variable and another. Even if we found a strong positive correlation between two variables, we cannot assume that one co-variable brought about that effect.

Question 8

What are the strengths of correlations?

Answer 8

• Correlations are a useful preliminary tool for research. By assessing the strength and direction of a relationship, they provide a precise and quantifiable measure of how two variables are related. This may suggest ideas for possible future research if variables are strongly related or demonstrate an interesting pattern. Correlations are often used as a starting point to assess possible patterns between variables before researchers commit to an experimental study.
• Correlations are relatively quick and economical to carry out. There is no need for a controlled environment and no manipulation of variables is required (making it more ethical). Data collected by others (secondary data such as government statistics) can be used, which means correlations are less time-consuming than experiments.

Question 9

What are the limitations of correlations?

Answer 9

• As a result of the lack of experimental manipulation and control within a correlation, studies can only tell us how variables are related but not why. Correlations cannot demonstrate cause and effect between variables and therefore we do not know which co-variable is causing the other to change. So, establishing the direction of the effect is an issue. Correlation doesn’t mean causation.
• It may also be the case that another untested variable is causing the relationship between the two co-variables we are interested in - an intervening variable (also known as the third variable problem). Thus, the key unaccounted-for variable, in effect, is causing the relationship between the other two co-variables.
• Largely because of the issues above, correlations can occasionally be misused or misinterpreted. Relationships between variables are sometimes presented as causal when they aren’t - especially by the media. This is because there could be many intervening or ‘third’ variables at work.