Computes the difference (x minus y) on every Multi-d' index,
for example simultaneous versus sequential lineups, or high- versus
low-similarity lineups. When both objects carry bootstrap draws, standard
errors, percentile intervals and normal-approximation p-values are given
for each difference. The two conditions are treated as independent samples:
the standard error is the square root of the sum of the two bootstrap
variances, and the interval is taken from differences between randomly
re-paired draws, so the result does not depend on whether the two fits used
the same seed.
Usage
compare_multid(x, y, labels = c("x", "y"), seed = NULL)Arguments
- x, y
Objects of class
"multid"frommake_multid, fitted with the samefiller_rate.- labels
Names for the two conditions.
- seed
Optional random seed for re-pairing the bootstrap draws.
Examples
# Simultaneous vs sequential lineups, Lee & Penrod's (2019) Table 3
sim <- make_multid(counts = c(G = 52, Fp = 25, Rp = 24, I = 28, Fa = 26, Ra = 46),
correction = "none")
sqn <- make_multid(counts = c(G = 44, Fp = 19, Rp = 39, I = 15, Fa = 17, Ra = 68),
correction = "none")
compare_multid(sim, sqn, labels = c("simultaneous", "sequential"))
#> Multi-d' comparison: simultaneous minus sequential
#>
#> index simultaneous sequential difference
#> GI 0.620 0.864 -0.243
#> GFp 0.720 0.719 0.001
#> IFa 0.061 -0.082 0.143
#> FaFp 0.039 -0.062 0.101
#> RaRp 0.614 0.767 -0.153
#> tp_bias 0.106 -0.048 0.154
#> siphoning 0.659 0.801 -0.142
#> ifa_vs_fair 1.276 0.908 0.367