1. Correlation Studies

2. Learning Objectives
Understand what is meant by a
correlation study.
Be able to explain the difference
between a positive, negative and zero
correlation.
Be able to explain the strengths and
weaknesses of using a correlation study.

3. Key Terms
See sheet

4. Correlation Studies.
 A process, rather than an actual
method
 Methods to gain a correlation analysis:
1. Self report: questionnaires/ interviews.
2. Observations
 It is the way that the data is analysed
which is important.

5. Correlation analysis
 Looking for a relationship between two variables e.g.
Aim: to investigate whether there is a relationship
between how often ethnic minority groups are shown
on television and the level of racism in society.
Method:
Variable 1 is measured by counting how often individuals
from ethnic groups appear on television in one day on
BBC1, ITV1 and Channel 4.
Variable 2 is measured using an interview to assess
partcipants’ racist attitudes.
Write a hypothesis for the above study

6. Hypothesis:
There will be a significant correlation
between the number of times that
individuals from ethnic minority groups
appear on television in one day across
BBC1, ITV1 and Channel 4 and
participants’ racist attitude scores as
measured by an interview.

7. Examples of correlations
You have 2 minutes for yourself and a
partner to come up with as many
correlations that you can think of, which
a psychologist many be interested in.
Just make them up!!!

8. Quantitative Data
 Correlational analysis can only be done on
quantitative data as it is a statistical process.
 Amount
 Time
 Score
 The strength and direction of a relationship is
measured.
 The relationship can be shown graphically using a
scattergram.
 A correlation co-efficient, which is between -1 and +1,
measures the relationship.
 Correlations can be categorised into positive,
negative and zero correlations.

9. Positive Correlation (r=1)
As one variable increases then so does
the other variable.
Example?
A perfect positive correlation has a co-
efficient of +1. This means that the two
variables increase in the exact relation
to one another.

10. Negative Correlation (r= -1)
There is a relationship
As one variable increases the other
variable decreased.
Example?
A perfect negative correlation has a co-
efficient of -1. This means that one
variable increases at exactly the same
rate as the other decreases.

11. Zero Correlation (r= 0)
There is no clear relationship
Example?
A true zero correlation has a co-efficient
of 0.0 This means that there is
absolutely no indication of a pattern
between variables.

12. Advantages and Disadvantages
See correlational studies handout.

13. Summary
 A correlation study is not an experiment.
 A correlation study measures the relationship between
two variables.
 A positive correlation means two variables change in
the same direction, a negative correlation means they
change in the opposite direction and a zero correlation
means they show no pattern of relationship.
 Correlations do not allow researchers to establish
cause and effect.
 They allow them to statistically analyse naturally
occurring events that could not be set up
experimentally.