itemtable: Summary of DIF items In pwrRasch: Statistical Power Simulation for Testing the Rasch Model

Description

This function builds a table of DIF items specified in the `pwrrasch` object

Usage

 `1` ```itemtable(object, all = FALSE, digits = 2) ```

Arguments

 `object` `pwrrasch` object `all` If `TRUE`, all items are included in the table. `digits` Integer indicating the number of decimal places.

Author(s)

Takuya Yanagida takuya.yanagida@univie.ac.at, Jan Steinfeld jan.steinfeld@univie.ac.at

Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```## Not run: # item parameters ipar2 <- ipar1 <- seq(-3, 3, length.out = 20) # model differential item function (DIF) ipar2[10] <- ipar1[11] ipar2[11] <- ipar1[10] # simulation for b = 100 simres <- pwr.rasch(100, ipar = list(ipar1, ipar2)) itemtable(simres) ## End(Not run) ```

Example output

```|----------------------------------------------------------|
| pwrRasch 0.1-2 (2015-09-28)                              |
| Statistical Power Simulation for Testing the Rasch Model |
|----------------------------------------------------------|
--------------------------------------------------------
Call:    pwr.rasch(b = 100, ipar = list(ipar1, ipar2))
Time:    2018-12-21 03:33:55
R:       R version 3.4.4 (2018-03-15)
Package: pwrRasch version 0.1-2 (2015-09-28)
--------------------------------------------------------
Conducting H0 simulation...    2018-12-21 03:33:55
Conducting H1 simulation...    2018-12-21 03:33:56
Finished simulation...         2018-12-21 03:33:56
--------------------------------------------------------
Time difference of 1.7 secs

Statistical Power Simulation for the Rasch model

b (number of persons in each group):  100
c (number of items):                  20
simulation runs:                      1000

Estimated statistical power:  0.104
Nominal significance level:   0.05
Empirical significance level: 0.054
--------------------------------------------------------

Summary of DIF items specified in the pwrrasch object

item parameters:  [-3, 3]
n items:          20
n DIF items:      2

Pos10 Pos11 SUM
ipar1 -0.16  0.16 0.0
ipar2  0.16 -0.16 0.0
DIF    0.32  0.32 0.6
```

pwrRasch documentation built on May 1, 2019, 10:37 p.m.