An investigator wants to arrange the 15 items on her scale of language impairment on the basis of the order in which language skills appear in development. Not being entirely confident that she has selected the correct ordering of skills, she asks another professional to rank the items from 1 to 15 in terms of the order in which he thinks they should appear.

The data are given below.

Investigator: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Consultant: 1 3 2 4 7 5 6 8 10 9 11 12 15 13 14

a. Use Pearson’s formula (r) to calculate Spearman’s .

b. Discuss what the results tell you about the ordering process.

10.13. For the data in Exercise 10.12,

a. Compute Kendall’s .

b. Test for significance.