Spearman's Rank

Question 1

why would spearman’s rank have to be used instead of PMCC?

Answer 1

• data not coming from a parents bivariate normal distribution so PMCC is not valid
• can deal with non-numerical data

Question 2

what is the formula for spearman’s correlation coefficent?

Answer 2

1. rank the two variables

check by find r of ranked lists

Question 3

what does the spearman’s rank coefficent tell us?

Answer 3

same thing as PMCC but talks about association rather than correlation

Question 4

what are the steps for hypothesis testing for spearman’s rank?

one tailed

Answer 4

1. define null hypothesis as an overall statment “ there is no association between the two variables” - in context
2. define the alternate hypothesis as an overall statment the is positive/ negative association between the two varibles
3. calculate the spearman’s rank correlation coefficent
4. read of critical value from data sheet