A common concern for students (and teachers) is the assignment of grades for essays or term papers. Because there are no absolute right or wrong answers, these grades must be based on a judgment of quality. To demonstrate that these judgments actually are reliable, an English instructor asked a colleague to rank-order a set of term papers. The ranks and the instructor's grades for these papers are as follows:

a. Compute the Spearman correlation for these data.

b. Is the Spearman correlation statistically significant? Use a two-tailed test with α = .05.

Rank Grade 1 A B A 4 B B 6. 9. 10 D 11