correlations

what do correlations measure?

two co-variables to see whether there is a relationship between them

what type of data do correlations use?

quantitative data

what are correlations represented on?

scatter graphs

what are coefficients?

a statistical measure that indicates the strength and direction of the relationship between two variables

• it is a value between -1 and +1

what are the types of correlations?

• positive correlation

• negative correlation

• zero correlation

what is a positive correlation?

as one variable increases or decreases, the other variable does the same

a positive correlation has a … coefficient

positive

what is a negative correlation?

as one variable increases, the other decreases

a negative correlation has a … coefficient

negative

what is a zero correlation?

there is no relationship between the two variables

what is the difference between correlations and experiments?

in a correlation, there is no manipulation of a variable therefore it isn’t possible to establish cause and effect between co-variables

what are the strengths of correlations?

• can study relationships between variables that occur naturally

• can measure things that cannot be measured experimentally

what are the weaknesses of correlations?

• direction of causation can’t be identified - don’t demonstrate cause and effect so we don’t know which covariable is causing the change in the other

• third variable problem - an untested variable is causing the relationship between the co-variables