agreement {agrmt}

Calculate van der Eijk's measure of agreement A

Description

Calculate agreement in ordered rating scales. This function implements van der Eijk's (2001) measure of agreement A, which can be used to describe agreement or consensus among respondents.

Usage

agreement(V, old = FALSE)

Arguments

V

A frequency vector

old

Optional argument if you wish to use the deprecated algorithm for agreement A, as outlined in van der Eijk's article. There is normally no reason to set the old argument.

Details

This is the main function to calculate agreement. A frequency vector describes the number of observations in a given category. For example, the vector [10,20,30,15,4] describes 10 observations with position 1, 20 observations with position 2, 30 observations with position 3, 15 observations with position 4, and 4 observations with position 5. At least three categories are required to calculate agreement.

Polarization can be measured by extension. A convenience function polarization is provided.

Value

The function returns the measure of agreement A. A is 1 if there is perfect unimodality (=agreement); A is 0 if there is perfect uniformity; A is -1 if there is perfect bimodality (=lack of agreement)

Author(s)

Didier Ruedin

References

van der Eijk, C. 2001. Measuring agreement in ordered rating scales. Quality and Quantity 35(3):325-341. <DOI: 10.1023/A:1010374114305>

See Also

polarization

Examples

# Sample data
V <- c(30,40,210,130,530,50,10)
# Calculate agreement A
agreement(V)
# The rate of agreement is given as 0.6113333