Word Doc Week 5

Question 1

Pearson’s Correlation (r)

Answer 1

Also Known As:

• Pearson’s product-moment correlation
• Pearson’s Correlation
• Correlation
• r

One of the most useful and commonly used statistical tests

Question 2

Convential Thought: Pearson’s (r)

Answer 2

• Measures strenght and direction of a Linear Relationship between two continuous/scale variables
• Asks: is there a statistically significant relationship between two continuous/scale variables
  
  • Strength - size/magnitude of relationship
  • Direction - Positive or Negative
  • Linear - Straight Line

Question 3

How to write up Pearson’s (r)

Answer 3

There was a significant correlation between educational level and job prestige, r(N =1415) = .52, p < .001.

Question 4

Features of Pearson’s (r)

Answer 4

• Must be between +1 and -1
• Negative correlations are as important positive correlations
• When you square r you use R² which tells us the level of overlapping or shared variance
• If there is no correlation then r = 0
• Only assesses linear component of the relationship

Question 5

What happens if the r relationship is non linear

Answer 5

• r will be calculated but will be misleading
• Always use draw scatterplots for comparison

Question 6

Negative Relationship/Correlation

Answer 6

• When scores on one variable go up, scores on another will go down
• High scores in one variable are associated with low scores on another variable

eg: correlation between depression and quality of life is negative. As depression increases, quality of life decreases. As scores on depression go up, scores on quality of life go down.

Question 7

Correlation Matrix

Answer 7

Running every possible correlation from a set of variables:

Question 8

Correlation Coefficient = +1

Answer 8

A perfect positive relationship.

Question 9

Correlation Coefficient = 0.8

Answer 9

A fairly strong positive relationship.

Question 10

Correlation Coefficient = 0.6

Answer 10

A moderate positive relationship.

Question 11

Correlation Coefficient = 0

Answer 11

• As one value increases, there is no tendency for the other value to change in a specific direction.
• No relationship.

Question 12

Correlation Coefficient = -1

Answer 12

A perfect negative relationship.

Question 13

Correlation Coefficient = -0.8

Answer 13

A fairly strong negative relationship.

Question 14

Correlation Coefficient = -0.6

Answer 14

A moderate negative relationship.