Raw Simple And Extended Percentage Agreement

Computes raw simple and extended percentage agreement among raters.

Agree(x, tolerance = 0, na.rm = FALSE)

Arguments

x: a data.frame or a \(k \times m\) matrix, k subjects (in rows) m raters (in columns).
tolerance: number of successive rating categories that should be regarded as rater agreement (see details).
na.rm: logical, indicating whether NA values should be stripped before the computation proceeds. If set to TRUE only the complete cases of the ratings will be used. Defaults to FALSE.

Details

Using extended percentage agreement (tolerance != 0) is only possible for numerical values. If tolerance equals 1, for example, raters differing by one scale degree are interpreted as agreeing.

Value

numeric value of coefficient of interrater reliability

The number of finally (potentially after omitting missing values) used subjects and raters are returned as attributes:

subjects: the number of subjects examined.
raters: the number of raters.

Author

Matthias Gamer <m.gamer@uke.uni-hamburg.de>,
some editorial amendments Andri Signorell <andri@signorell.net>

Examples

categ <- c("V", "N", "P")
lvls  <- factor(categ, levels=categ)
rtr1  <- rep(lvls, c(60, 30, 10))
rtr2  <- rep(rep(lvls, nlevels(lvls)), c(53,5,2, 11,14,5, 1,6,3))
rtr3  <- rep(rep(lvls, nlevels(lvls)), c(48,8,3, 15,10,7, 3,4,2))

Agree(cbind(rtr1, rtr2))       # Simple percentage Agreement
#> [1] 0.7
#> attr(,"subjects")
#> [1] 100
#> attr(,"raters")
#> [1] 2
Agree(data.frame(rtr1, rtr2))  # can be a data.frame
#> [1] 0.7
#> attr(,"subjects")
#> [1] 100
#> attr(,"raters")
#> [1] 2
Agree(cbind(rtr1, rtr2, rtr3)) # Simple percentage Agreement
#> [1] 0.6
#> attr(,"subjects")
#> [1] 100
#> attr(,"raters")
#> [1] 3

Agree(cbind(rtr1, rtr2), 1)    # Extended percentage Agreement
#> [1] 0.97
#> attr(,"subjects")
#> [1] 100
#> attr(,"raters")
#> [1] 2