scDIFtest-Methods {scDIFtest}

Methods for the scDIFtest-class

Description

print, summary, and plot methods for objects of the scDIFtest-class, as returned by scDIFtest. See details for more information about the methods.

Usage

## S3 method for class 'scDIFtest'
print(x, item_selection = NULL, ...)

## S3 method for class 'scDIFtest'
summary(object, method = "fdr", ...)

## S3 method for class 'scDIFtest'
plot(x, item_selection = NULL, ...)

Arguments

x

an object of class scDIFtest

item_selection

either NULL or an integer vector selecting the item numbers. When items = NULL (the default), the DIF test is done for all items.

...

other arguments passed to the method.

object

an object of class scDIFtest

method

one of the strings in p.adjust.methods.

Details

The print method, whenitem_selection = NULL, gives a summary of all the tests that were executed (i.e., for all items). When specific items are selected, the print method is called repeatedly for each individual sctest corresponding with the selected items.

The summary method computes a data frame with a row for each item that was included in the test. The columns are:

item_type

The estimated IRT model per item

n_est_pars

The number of estimated parameters per item

stat

The value for the used statistic per item

p_value

The p-value per item

p_fdr

The corrected p-value controlling the false discovery rate (Benjamini & Hochberg, 1995). See p.adjust for details.

The plot method call the plot method repeatedly for the gepf that corresponds with the executed score test for each of the selected items. When no items are selected, the plot method results in an error.

References

Benjamini, Y., and Hochberg, Y. (1995). Controlling the false discovery rate: a practical and powerful approach to multiple testing. Journal of the Royal Statistical Society Series B, 57, 289-300.