Spearman's Rank Correlation Coefficient

Question 1

What is the formula for Spearman’s Rank?

Answer 1

Rs = 1 - 6(Σd^2)/n(n^2-1)

where:

• d is the x-ranks minus the y-ranks
• n is the number of x values

Question 2

What does Spearman’s rank show?

Answer 2

1. Measures strength of correlation between two sets of data
2. The closer Rs is to 1, the stronger the POSITIVE correlation
3. The closer Rs is to -1, the stronger the NEGATIVE correlation
4. If Rs is 0, there is no correlation

Question 3

Finish the sentence:

“Spearman’s rank is always…”

Answer 3

Less than 1