Question

Which correlation coefficient is the most appropriate for measuring the relationship between Right/ Left Handedness and Reading Comprehension Scores?

A. Spearman Rho

B. chisquare

C. phi coefficient

D. point biserial

How do you choose between Spearman Rho and Point Biserial? I am stuck between these two answers.

Answer 1

SOL::-From the given data,correlation coefficient is the most appropriate for measuring the relationship between right/left handedness.

Here handedness is a discontinuous variable,where as on the other hand reading comprehension scores are continuous variables.

so for the given data,POINT BISERIAL is te correlation coefficient of most appropriate for measuring the relationship between right and left handedness.

option (D) is correct answer.

SPEARMEN RHO:::-

The Spearman rank correlation coefficient, rs, is the nonparametric version of the Pearson correlation coefficient.

Your data must be ordinal, interval or ratio.

Spearman’s returns a value from -1 to 1,

where:
+1 = a perfect positive correlation between ranks
-1 = a perfect negative correlation between ranks
0 = no correlation between ranks.

POINT BISERIAL:::-

It is the special case of pearsons correlation coefficient.

It measure the relationship between two variables::-

• One continuous variable (must be ratio scale or interval scale).
• One naturally binary variable.

it is denoted by point correlation coefficient ,rpbi.