Chi Square Goodness of Fit Test — ifr_chisq_gof_test • inferr

Test whether the observed proportions for a categorical variable differ from hypothesized proportions

Usage

ifr_chisq_gof_test(data, x, y, correct = FALSE)

Arguments

data: a data.frame or tibble
x: factor; column in data
y: expected proportions
correct: logical; if TRUE continuity correction is applied

Value

ifr_chisq_gof_test returns an object of class "ifr_chisq_gof_test". An object of class "ifr_chisq_gof_test" is a list containing the following components:

categories: levels of x
chisquare: chi square statistic
deviation: deviation of observed from frequency
degrees_of_freedom: chi square degrees of freedom
expected_frequency: expected frequency/proportion
n_levels: number of levels of x
observed_frequency: observed frequency/proportion
pvalue: p-value
sample_size: number of observations
std_residuals: standardized residuals
varname: name of categorical variable

Deprecated Function

infer_chisq_gof_test() has been deprecated. Instead use ifr_chisq_gof_test()

References

Sheskin, D. J. 2007. Handbook of Parametric and Nonparametric Statistical Procedures, 4th edition. : Chapman & Hall/CRC.

See also

Examples

ifr_chisq_gof_test(hsb, race, c(20, 20, 20, 140))
#>     Test Statistics     
#> -----------------------
#> Chi-Square       5.0286 
#> DF                    3 
#> Pr > Chi Sq      0.1697 
#> Sample Size         200 
#> 
#>                          Variable: race                           
#> -----------------------------------------------------------------
#> Category    Observed    Expected    % Deviation    Std. Residuals 
#> -----------------------------------------------------------------
#>    1           24          20          20.00            0.89      
#>    2           11          20         -45.00           -2.01      
#>    3           20          20           0.00            0.00      
#>    4          145         140           3.57            0.42      
#> -----------------------------------------------------------------

# apply continuity correction
ifr_chisq_gof_test(hsb, race, c(20, 20, 20, 140), correct = TRUE)
#>     Test Statistics     
#> -----------------------
#> Chi-Square       4.3821 
#> DF                    3 
#> Pr > Chi Sq      0.2231 
#> Sample Size         200 
#> 
#>                          Variable: race                           
#> -----------------------------------------------------------------
#> Category    Observed    Expected    % Deviation    Std. Residuals 
#> -----------------------------------------------------------------
#>    1           24          20          17.50            0.78      
#>    2           11          20         -47.50           -2.12      
#>    3           20          20          -2.50           -0.11      
#>    4          145         140           3.21            0.38      
#> -----------------------------------------------------------------