Description Usage Arguments Details Value Author(s) References See Also Examples

Computes iota as an index of interrater agreement of quantitative or nominal multivariate observations.

1 2 |

`ratings` |
list of n*m matrices or dataframes with one list element for each variable, n subjects m raters. |

`scaledata` |
a character string specifying if the data is '"quantitative"' (default) or '"nominal"'. If the data is organized in factors, '"nominal"' is chosen automatically. You can specify just the initial letter. |

`standardize` |
a logical indicating whether quantitative data should be z-standardized within each variable before the computation of iota. |

Each list element must contain observations for each rater and subject without missing values.

In case of one categorical variable (only one list element), iota reduces to the Fleiss exact kappa coefficient, which was proposed by Conger (1980).

A list with class '"irrlist"' containing the following components:

`$method` |
a character string describing the method applied for the computation of interrater reliability. |

`$subjects` |
the number of subjects examined. |

`$raters` |
the number of raters. |

`$irr.name` |
a character string specifying the name of the coefficient. |

`$value` |
value of iota. |

`$detail` |
a character string specifying if the values were z-standardized before the computation of iota. |

Matthias Gamer

Conger, A.J. (1980). Integration and generalisation of Kappas for multiple raters. Psychological Bulletin, 88, 322-328.

Janson, H., & Olsson, U. (2001). A measure of agreement for interval or nominal multivariate observations. Educational and Psychological Measurement, 61, 277-289.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 | ```
data(diagnoses)
iota(list(diagnoses)) # produces the same result as...
kappam.fleiss(diagnoses, exact=TRUE)
# Example from Janson & Olsson (2001), Table 1
photo <- list()
photo[[1]] <- cbind(c( 71, 73, 86, 59, 71), # weight ratings
c( 74, 80,101, 62, 83),
c( 76, 80, 93, 66, 77))
photo[[2]] <- cbind(c(166,160,187,161,172), # height rating
c(171,170,174,163,182),
c(171,165,185,162,181))
iota(photo)
iota(photo, standardize=TRUE) # iota over standardized values
``` |

```
Loading required package: lpSolve
iota for nominal data (1 variable)
Subjects = 30
Raters = 6
iota = 0.442
Fleiss' Kappa for m Raters (exact value)
Subjects = 30
Raters = 6
Kappa = 0.442
iota for quantitative data (2 variables)
Subjects = 5
Raters = 3
iota = 0.755
iota for quantitative data (2 variables)
Subjects = 5
Raters = 3
iota = 0.745
Variables have been z-standardized before the computation
```

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.