tests of correlation -spearman’s rho

Question 1

why use spearman

Answer 1

-test of correlation between to sets of value
-ordinal data (also interval data)

Question 2

what is step 1 the table of ranks?

Answer 2

-rank each set of scores seperately in each group/condition from highest to lowest
-if two scores share the same ranks find the mean of their total ranks

Question 3

what is step 2 calc the difference?

Answer 3

-find the difference between each pair of ranks and sqaure the difference
-add up the sqaured differences

Question 4

what is step 3- work out the value of rho

Answer 4

-use the formula in revision folder

Question 5

what is step 4 -calaculated and critical values

Answer 5

-check what tail and if 0.05?
-if calculated value of rho is less than the critical value the result is not significant
-we have to accept the null hypothesis
-but if the result is negative its wrong direction so hypothesis is would not be accepted even if calc value was large.

Question 6

look at revision folder for diagrams