Correlations

What are correlations? (3)

Establishing if their is a relationship between two variables, how strong the relationship is, and the direction of the relationship

What is concurrent validity?

When a correlation is compared to an established study

What are 4 possible causes of correlations? (4)

covariable 1 is causing covariable 2, covariable 2 is causing covariable 1, both variables are caused by a third variable, correlation is due to chance

What is the third variable problem?

The third variable problem is when both variables are caused by a third variable

What is important to consider when investigating correlations?

Correlation alone is not compelling evidence of a causal link

How are correlations different from experiments? (3)

correlations examine the relationship between two or more variables without manipulating any variables, correlations identify an existence and strength of a relationship not a causation, therefore a correlation cannot prove anything

How are experiments different form correlations? (3)

Experiments involve manipulating one or more independent variables to observe their effect on a dependent variable, other factors are controlled, experiments allow researchers to establish a cause and effect

How is each covariable measured? (2)

each covariable is measured on a scale, so each participant gets a score for each covariable

What is a positive correlation?

the covariables increase and decrease together

What is a negative correlation? (2)

as one covariable increases, the other covariable decreases

What is a correlation co-efficient? (2)

A measure of the strength and direction of a correlation, a value between -1 and +1

What would a strong negative correlation be?

any value between -0.8 and -1

What would a strong positive correlation be?

any value between +0.8 and +1

What would a moderate positive correlation be?

any value between +0.8 and +0.4

What would a moderate negative correlation be?

any value between -0.8 and -0.4

What would a weak positive or negative correlation be?

any value between -0.4 and +0.4

How are correlations represented?

Correlations are represented on scattergrams

What key word should you use when referring to correlations in exam questions? (2)

relationship, correlation