Unexpected judgements of one judge, pair by pair

The comparison-level companion of judge_surprise. Each pair the judge met is oriented to its stronger object (higher consensus location) and given a standardised residual: z < 0 means the stronger object won less than its lead predicts – the judge backed the underdog. A matchup is an unexpected judgement when z falls at or below -flag_z and the pair was seen at least min_n times, i.e. the judge favoured the weaker object further than sampling noise explains.

Usage

judge_pair_surprise(fit, judge, min_n = 1L, flag_z = 1.96)

Arguments

fit

A paired-comparison fit from btl with judges.

judge

The judge to profile.

min_n

Pairs met fewer times are shown but never flagged.

flag_z

Absolute residual at or beyond which an upset is flagged.

Value

A list of class "rasch_btl_judge_pairs": pairs (per matchup: the stronger and weaker object and their locations, the location gap, times met n, residual z, the net_winner, and the surprise flag); all_locations; the judge and settings.

Examples

set.seed(1); objs <- LETTERS[1:6]; beta <- setNames(seq(-1.5, 1.5, len = 6), objs)
pr <- t(utils::combn(objs, 2))
d <- data.frame(a = rep(pr[, 1], each = 12), b = rep(pr[, 2], each = 12))
d$judge <- sample(paste0("J", 1:5), nrow(d), TRUE)
d$win <- ifelse(runif(nrow(d)) < plogis(beta[d$a] - beta[d$b]), d$a, d$b)
judge_pair_surprise(btl(d, "a", "b", "win", judge = "judge"), "J1")
#> Judge J1: 40 comparisons over 15 matchups
#> Unexpected judgements (weaker object favoured beyond its lead):
#>   F vs C  (gap 2.12, z = -2.89, upset)