Correlation

Question 1

What is a correlation?

Answer 1

An analysis of the relationship between co variables

Question 2

Variables are not manipulated in correlational studies, what happens instead during correlational studies?

What is an example of co variables? (school related)

Answer 2

Since variables are not manipulated, instead two co - variables are measure and compared to look for a relationship. One or both co - variables may be pre existing

Attendance at school and Grades achieved

Question 3

What are the three outcomes of a correlation study?

Answer 3

A positive correlation, negative correlation and zero (no) correlation

Question 4

What is the outcome of a positive correlational study show?

Answer 4

A positive correlational study shows that as one co variable increases so does the other one, not necessarily at the same rate

Question 5

What is the outcome of a zero (no) correlation study show?

Answer 5

A zero (no) correlational study shows no relationship between the co - variables

Question 5

What is the outcome of a negative correlational study show?

Answer 5

A negative correlational study shows that as co variable - increases the other co - variable decreases, not necessarily at the same time

Question 6

How can relationships between co - variables be represented?

Answer 6

Relationships between co - variables can be shown with scattergraphs or by calculating the correlation coefficient, which is expressed as a numerical value

Question 7

What is the correlation coefficient?

Answer 7

The correlation coefficient is a numerical value that represents both the direction and strength of the relationship between the co - variables

Question 8

How is the correlation coefficient expressed?

Answer 8

Expressed as values between -1 and +1

Question 9

What does a positive correlation look like as a correlation coefficient?
What does a negative correlation look like as a correlation coefficient?
What does a zero (no) correlation relationship look like as a correlation coefficient?

Answer 9

Positive correlation: +1
Negative correlation: -1
Zero (no) correlation: 0

Question 10

Both positive and negative coefficient correlations can be described as: weak, moderate or strong

What type of descriptions would these coefficient correlation values gain:
1. 0.03
2. -0.08

Answer 10

1. 0.03 = weak positive correlation
2. -0.08 - strong negative correlation

Question 11

What is a limitation of a correlation study? (does not establish cause and effect)

Answer 11

Correlation studies lack experimental manipulation and control, as a result correlation studies can only tell us how variables are related but not why. Correlations cannot establish cause and effect between variables and therefore we do not know which co - variable is causing the other to change

Question 12

What is a strength of a correlation study? (time + cost)

Answer 12

Correlational studies are relatively quick and economical to carry out. There is no need for a controlled environment and no manipulation of variables is required

Question 13

What is a limitation of a correlational study? (non
- linear relationships)

Answer 13

Correlations are less successful with non - linear relationships for example, the number of hours worked and levels of happiness

Question 14

What is a strength of a correlational study? (data availability)

Answer 14

Correlation studies have data readily available to conduct research. Therefore, ethical issues are less likely to be an issue

Question 15

What is the difference between correlations and experiments?

Answer 15

Experiments involve deliberate manipulation of the independent variable to measure the impact on the dependent variable. This means from the results a cause and effect relationship can be established.

Whereas, in correlation studies, there is no manipulation one variable and therefore not possible to establish cause and effect between a co variable and another.