Correlations

Question 1

What is a correlation?

Answer 1

Correlations investigate the strength of a relationship between 2 variables (co-variables)

Question 2

What are the three types of correlation:

Answer 2

• positive
• negative
• no correlation

Question 3

Positive correlation

Answer 3

As one variable increases, so does the other

Question 4

Negative correlation

Answer 4

As one variable increases, the other decreases

Question 5

What are the two ways in which correlation data is presented?

Answer 5

• Scatter graph
• Correlation coefficients

Question 6

If you get asked to draw a scatter graph, what are marks allocated for?

Answer 6

(1) Clear and specific title outlining both variables - “A scatter graph displaying the relationship between V1 and V2”
DONT FORGET TO APPLY
(1) Labelling X and Y axis + use units if applicable
(1) Accurate plotting

Question 7

Correlation coefficients

Answer 7

The strength and direction (positive/negative) can be expressed by a numerical value known as correlation coefficient.
- negative correlation coefficient indicates a negative correlation
- positive correlation coefficient indicates a positive correlation

Question 8

Indicates strength of correlation:
1-0.7

Answer 8

Strong correlation

Question 9

Indicates strength of correlation:

0.7-0.4

Answer 9

Moderate correlation

Question 10

Indicates strength of correlation:

0.4-0.1

Answer 10

Weak correlation

Question 11

Indicates strength of correlation:

0.1-0

Answer 11

No correlation

Question 12

Interpreting correlations exam q:

Answer 12

1) identify direction of correlation and strength if applicable
2) state what the direction of correlation is between and be specific with covariables
3) explain what happens to variables in the type of correlation identified, e.g, “As _____ increases, so does ______”

Question 13

2 Strengths of correlations:

Answer 13

+ good preliminary tool for research- good starting point. By helping identify rs between 2 variables, allows grounds to further investigate the variables through methods like lab experiments to investigate C+E between 2 variables
+ since correlation only involves gathering/ measuring data + no manipulation- useful for variables which may be unethical to manipulate in exp setting

Question 14

One weakness of correlations:

Answer 14

• Variables not controlled + cannot be manipulated in any way. Only informs us that they are related, not if variable A causes variable B or vise versa. There may be a 3rd variable affecting both variables