
Resolution of a ranking built from noisy risk scores
Source:R/fairness_bounds.R
morie_ranking_resolution.RdTwo people with true scores \(t_1 < t_2\) are ranked by estimates that
noise can move by up to \(\delta\) each. Whenever the true gap is below
\(2\delta\) an admissible noise pair reverses the order
(Research.P5.rank_reversal_exists); whenever it exceeds
\(2\delta\) no admissible noise can (rank_stable_of_gap). The
resolution of a ranking is therefore twice the noise half-width; on a
probability scale with interval half-widths near one half no pair has an
identified order (identified_scores_le). Given point estimates and
their half-widths, the function reports which pairs are identified and the
share of pairs that are not (the Baldus proportionality-review situation
in Weisburd & Britt ch. 1, where most intervals covered nearly all of [0, 1]).
Value
A list with n_pairs, identified_pairs (a logical
matrix: order identified if the estimates differ by more than the sum of
the two half-widths), share_unidentified, resolution
(twice the largest half-width) and theorems.
Examples
morie_ranking_resolution(c(0.2, 0.35, 0.8), half_width = c(0.1, 0.1, 0.05))
#> $n_pairs
#> [1] 3
#>
#> $identified_pairs
#> [,1] [,2] [,3]
#> [1,] NA FALSE TRUE
#> [2,] FALSE NA TRUE
#> [3,] TRUE TRUE NA
#>
#> $share_unidentified
#> [1] 0.3333333
#>
#> $resolution
#> [1] 0.2
#>
#> $theorems
#> [1] "Research.P5.rank_reversal_exists" "Research.P5.rank_stable_of_gap"
#> [3] "Research.P5.identified_scores_le"
#>