Krippendorff's alpha (nominal, binary, fully crossed)

Fully-crossed design (m_i = k for all i). Hayes-Krippendorff coincidence- matrix reduction: o_{01} = 2 * sum_i r_i * (k - r_i) / (k - 1), n_0 = N*k - sum(r_i), n_1 = sum(r_i), n_total = N*k, alpha = 1 - (n_total - 1) * o_{01} / (2 * n_0 * n_1).

Usage

obs_krippendorff_alpha(Y)

Arguments

Y

N x k integer matrix in {0L, 1L}.

Value

Single numeric.

Details

Returns NA_real_ (with a note attribute) if the design is degenerate (no positives or no negatives in Y).

As of v0.6.0, alpha is not part of the Report Card panel or the delta_hat coefficient set: in the binary fully-crossed case it coincides with Fleiss' kappa asymptotically (median absolute difference 0.00024 across the 10,140-cell calibration grid). This function is exported for users who need the value for cross-study comparison.