func_size {r4lineups}

Functional Size

Description

This function computes functional size (N/D), where N = number of mock witnesses, & D = number of mock witnesses choosing the target

Usage

func_size(lineup_vec, target_pos)

Arguments

lineup_vec

A numeric vector of lineup choices

target_pos

A scalar, representing target position in lineup. Must be declared by user

Details

An estimation of the number of plausible lineup members in a given lineup.

Value

Functional size of lineup

References

Tredoux, C. G. (1998). Statistical inference on measures of lineup fairness. Law and Human Behavior, 22(2), 217-237.

Tredoux, C. (1999). Statistical considerations when determining measures of lineup size and lineup bias. Applied Cognitive Psychology, 13, S9-S26.

Wells, G. L.,Leippe, M. R., & Ostrom, T. M. (1979). Guidelines for empirically assessing the fairness of a lineup. Law and Human Behavior, 3(4), 285-293.

Examples

#Data:
lineup_vec <- round(runif(100, 1, 6))
target_pos <- 3

#Call:
x <- func_size(lineup_vec, target_pos)
x <- func_size(lineup_vec, 3)