8.20 Table 8.17 displays diagnoses of multiple sclerosis for two neurologists. The categories are (1) Certain multiple sclerosis, (2) Probable multiple sclerosis,

(3) Possible multiple sclerosis, and (4) Doubtful, unlikely, or definitely not multiple sclerosis.

a. Use the independence model and residuals to study the pattern of agreement.

Interpret.

b. Use a more complex model to study the pattern and strength of agreement between the neurologists. Interpret results.

c. Use kappa to describe agreement. Interpret.