# consensus: Calculate Tastle and Wierman's measure of consensus In agrmt: Calculate Concentration and Dispersion in Ordered Rating Scales

## Description

Calculate consensus in ordered rating scales. This function implements Tastle and Wierman's (2007) measure of consensus (ordinal dispersion), which can be used to describe agreement, consensus, dispersion, or polarization among respondents.

## Usage

 `1` ```consensus(V) ```

## Arguments

 `V` A frequency vector

## Details

This function calculates consensus following Tastle and Wierman (2007). The measure of consensus is based on the Shannon entropy. 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.

If you come across an error that the vector supplied does not contain whole numbers, try `round(V,0)` to remove any detritus from calculating the frequency vector.

## Value

The function returns the measure of consensus. It is 1 if there is perfect uniformity; it is 0 if there is perfect bimodality (=lack of agreement)

Didier Ruedin

## References

Tastle, W., and M. Wierman. 2007. Consensus and dissention: A measure of ordinal dispersion. International Journal of Approximate Reasoning 45(3): 531-545.

`agreement`

## Examples

 ```1 2 3 4 5``` ```# Sample data V <- c(30,40,210,130,530,50,10) # Calculate consensus consensus(V) # The degree of consensus is given as 0.7256876 ```

### Example output

```[1] 0.7256876
```

agrmt documentation built on July 18, 2021, 1:06 a.m.