Correlations

Question 1

Give the definition of a correlation (2 marks)

Answer 1

A non experimental method that measures the strength and direction of a relationship or link between two co-variables, these can be seen as positive or negative.

Question 2

Describe a positive correlation

Answer 2

• The points lie close to a straight line which has a positive gradient
• this shows that as one variable increases the other increases

Question 3

Describe a negative correlation vs no correlation

Answer 3

• With a negative correlation, the points lie close to a straight line, which has a negative gradient. This shows that as one variable increases the other decreases.
  -However with no correlation, there is no pattern to the points. This shows that there is no connection between the two variables.

Question 4

Describe the main features of a correlation

Answer 4

• involves measuring two or more co-variables
• does not involve an IV or DV
• identifies the direction of a relationship positive, none, or negative
• can be used to analyse relationships in large amounts of data
• identifies the strength of a relationship, weak, moderate or strong

Question 5

How to design a correlation study

Answer 5

1. Create a name for the study and a hypothesis
2. Clearly operationalise, the two or more covariables intended to be measured
3. Attempt to control confounding variables
4. Display data on a scatter diagram
5. Use correlation coefficient to establish the strength and direction of the correlation between two co-variables - statistic between -1 and +1

Question 6

Give 2 strengths of a correlation

Answer 6

• can justify further research to establish cause and effect as you can quickly establish if there are correlational trends between variables
• there is no manipulation of the IV, so it is appropriate to use when studying sensitive issues that may be inappropriate to manipulate in a situation. E.g. life change

Question 7

Give 2 limitations of correlations

Answer 7

• it’s difficult to establish cause & effect between the 2 variables as it is only a relationship found between variables. Therefore other extraneous variables could be responsible for the relationship which may lower the internal validity. E.g. a positive correlation between the amount of violent watch on television and violent behaviour does not mean violent behaviour is caused by watching violence on television. There is just a relationship.
• correlations can be misinterpreted by the media & society when a link has been found between two variables, so they may assume a conclusion can be made about the causes for the relationship, which can then be misused by the public to support or contradict an argument

Question 8

Define correlation coefficients (2 marks)

Answer 8

A statistic, ranging from -1 to +1, which indicates a strength and direction of a correlation between 2 co-variables. -1 being a perfect negative correlation, 0 being no correlation, and +1 being a perfect positive correlation.