WEEK 9

Question 1

Pearson’s Correlation (Product moment)

Answer 1

Assumptions:
-data must be interval or ratio level
-data must be normally distributed
- no outliers

-related pairs, linearity between variables

Question 2

Linearity

Answer 2

A straight line relationship between x and y

Question 3

scatterplots and linearity

Answer 3

• we assign one variable to x and one to y
• Each person’s score on x and y should be plotted where they meet

Question 4

Types of Relationships

Answer 4

• Negative Linear relationship
  -Curvilinear relationship
• positive linear relationship
  -zero

Question 5

The Correlation Coefficient

Answer 5

The strength of the relationship between the two variables: correlation coefficient

+1 is a perfect positive relationship
-1 is a perfect negative relationship
0 is no linear relationship

Question 6

Common and shared variance

Answer 6

-the correlation coefficient is a ratio between the covariance and a measure of the separate variances
- when two variables are correlated, they share variance
e.g. ice cream sales and the weather 0.8 squared is 64%
- if the shared variance is greater than the unique variance, the correlation coefficient will be high

Question 7

Partial Correlation

Answer 7

• Calculates what the relationship between two variables would be if we could take away the influence of additional variables
  -this is called controlling for a third variable