# coverage: Coverage and consistency. In QCA3: Yet Another Package for Qualitative Comparative Analysis

## Description

Coverage and consistency.

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15``` ```coverage(x, ...) ## Default S3 method: coverage(x, y, alternative = c("less", "greater"),...) ## S3 method for class 'QCA' coverage(x, data, type = c("raw", "unique"), which = 1, ...) consistency(x,...) ## Default S3 method: consistency(x, y, alternative = c("less", "greater"), ...) ## S3 method for class 'QCA' consistency(x, data, which=1, ...) ```

## Arguments

 `x` a numeric vector of fuzzy set score for default method of coverage and consistency. A QCA object for QCA method of coverage. `y` a numeric vector of fuzzy set score. `alternative` specify the relationship between x and y. `data` The original data which are used to generate the QCA object. `which` length-1 positive integer to select a solution from the QCA object. `type` The type of coverage. `...` not used currently.

## Details

Given two fuzzy set score variables x and y, coverage returns the coverage of x by y, given their relationship; and consistency returns the consistency of x by y.

When alternative is "less", it returns coverage(x<=y). This is coverage for sufficent test. When "greater", it returns coverage(x>=y), it is coverage for necessary condition.

This value can be used to evaluate the importance or relevance of x as a necessary condition for Y. When coverage(x>=y) is small, the constraining effect of x on y is negligible. In other words, small value of coverage(x>=y) indicates en empirically trivial necessary condition (Ragin, 2008: 61).

## Value

For default method of coverage and consistency, the value is a length-1 numeric vector.

Ronggui HUANG

## References

Ragin, C. 2006. Set Relations in Social Research: Evaluating Their Consistency and Coverage Political Analysis,14(3):291-310.

Ragin, C. 2008, Redesigning social inquiry: fuzzy set and beyond. Chicago: The University of Chicago Press.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24``` ```## evaluate the congerage of necessary conditions for "no democratic consolidation" ## see help(CoD) for more information. ## coverage for necessary test for not-CoD (Schneider, 2009:77) coverage(1-CoD\$econdev,1-CoD\$cod,'greater') # not socioeconomically developed coverage(1-CoD\$demex,1-CoD\$cod,'greater') # no previous democratic experience coverage(pmin(1-CoD\$demex,1-CoD\$econdev),1-CoD\$cod,'greater') # not socioeconomic developed society without prior democratic experience ## coverage and consistency for QCA object rownames(CoD) <- CoD\$label tb6.4 <- reduce(CoD,'cod',c('econdev','eduhi','ethlihom','close','demex','nocom'), exp="positive",remainder='include',pre="fs") coverage(tb6.4, CoD) coverage(tb6.4, CoD,"unique") consistency(tb6.4, CoD) cbind(consistency(tb6.4, CoD),coverage(tb6.4,CoD),coverage(tb6.4,CoD,"unique")) ## put together ## coverage method for QCA object tb2<-reduce(policyChange~soc+pol+ind+are+foc,Yamasaki2009,cases="country") coverage(tb2,Yamasaki2009) ```

QCA3 documentation built on Jan. 15, 2017, 6:58 p.m.