23. Spearman's Rho & Pearson's r

Question 1

What is Spearman’s Rho

Answer 1

• Spearman’s Rho is a correlation coefficient.
• Spearman’s Rho correlation coefficient is an observed value used to see if theres a significant association between 2 variables that have at least ordinal data.
• To work out Spearman’s Rho correlation coefficient, you need values for 2 diff variables (eg. hours of sleep & test scores for 10 students).

Question 2

See pg126 for worked eg on Spearman’s Rho

Question 3

What can Spearman’s Rho be used for

Answer 3

Spearman’s Rho can be used to establish concurrent validity.

Question 4

What is Pearson’s r

Answer 4

• Pearson’s r is also a correlation coefficient.
• A Pearson’s r test investigates the association between 2 variables. Both variables must have interval or ratio data & be normally distributed.
• The correlation between the 2 variables will fall between -1 and +1. This value is called r.
• The closer r is to -1 or +1, the stronger the relationship.
• If r is positive, the relationship between the 2 variables is positive (one goes up, the other goes up).
  If r is negative, the relationship is negative (one goes down as the other goes up).

Question 5

See pg127 for worked eg of Pearson’s r

Question 6

What can Pearson’s r be used for

Answer 6

Pearson’s r can also be used to establish concurrent validity.