Some other measures, namely, all α from Krippendorff, and the new γ introduced in this article, are computed from observed and expected disagreements (instead of agreements), denoted here respectively D o and D e , and they define the final agreement by Equation (2).
a o − a e 1 − a e (1) the way the expected value is computed is the only difference between many coefficients (κ, S, π, and their generalizations), and is a controversial question.