Last data update: 2014.03.03

 R: Classical Item Analysis for Polytomous Items
ITEMAN2R Documentation

Classical Item Analysis for Polytomous Items

Description

Classical Item Analysis for Polytomous Items

Usage

ITEMAN2(data, options, ngroup = ncol(data) + 1, correction = TRUE)

Arguments

data

a data frame with N rows and m columns, with N denoting the number of subjects and m denoting the number of items.

options

a vector of numerical code of the response categories available for the items such as c(0,1,2,3). The minumum score is assumed to be 0.

ngroup

number of score groups to be use for plotting the item trace lines

correction

TRUE or FALSE. If it is TRUE, then an adjustment is made for point-biserial correlation.

Details

to be added later

Value

plots

a list object storing the item trace line plots for each item

Author(s)

Cengiz Zopluoglu

See Also

ITEMAN1 for classical item analysis of multiple-choice test items

Examples



data(timss2011_usa)

timss2011_usa$Q14B <- recode(var = timss2011_usa$Q14B,
                             recodes = "c(0)=3;c(1)=2;c(2)=1;c(3)=0")

timss2011_usa$Q14C <- recode(var = timss2011_usa$Q14C,
                             recodes = "c(0)=3;c(1)=2;c(2)=1;c(3)=0")

item.analysis <- ITEMAN2(data=timss2011_usa,
                         options=c(0,1,2,3),
                         ngroup=18,
                         correction=FALSE)

item.analysis$plots[[1]]   # Item Trace Line for the first item

# item.analysis$plots[[2]]   # Item Trace Line for the second item
# item.analysis$plots[[3]]   # Item Trace Line for the third item
# item.analysis$plots[[4]]   # Item Trace Line for the fourth item
# item.analysis$plots[[5]]   # Item Trace Line for the fifth item
# item.analysis$plots[[6]]   # Item Trace Line for the sixth item

Results


R version 3.3.1 (2016-06-21) -- "Bug in Your Hair"
Copyright (C) 2016 The R Foundation for Statistical Computing
Platform: x86_64-pc-linux-gnu (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

> library(ITEMAN)
Loading required package: ggplot2
Loading required package: polycor
Loading required package: mvtnorm
Loading required package: sfsmisc
Loading required package: car
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/ITEMAN/ITEMAN2.Rd_%03d_medium.png", width=480, height=480)
> ### Name: ITEMAN2
> ### Title: Classical Item Analysis for Polytomous Items
> ### Aliases: ITEMAN2
> 
> ### ** Examples
> 
> 
> 
> data(timss2011_usa)
> 
> timss2011_usa$Q14B <- recode(var = timss2011_usa$Q14B,
+                              recodes = "c(0)=3;c(1)=2;c(2)=1;c(3)=0")
> 
> timss2011_usa$Q14C <- recode(var = timss2011_usa$Q14C,
+                              recodes = "c(0)=3;c(1)=2;c(2)=1;c(3)=0")
> 
> item.analysis <- ITEMAN2(data=timss2011_usa,
+                          options=c(0,1,2,3),
+                          ngroup=18,
+                          correction=FALSE)
************************************************************************ 
ITEMAN: An R routine for Classical Item Analysis 
 
Cengiz Zopluoglu 
 
University of Miami 
Department of Educational and Psychological Studies 
Research, Measurement, and Evaluation Program 
 
c.zopluoglu@miami.edu 
 
Please report any programming bug or problem you experience to improve the code. 
************************************************************************* 
Processing Date:  Mon Jul  4 19:15:18 2016 
                                   ITEM STATISTICS 
 
       Mean Score Item Difficulty Point-Biserial Polyserial
Item 1      1.763           0.588          0.881      0.953
Item 2      1.599           0.533          0.779      0.838
Item 3      1.379           0.460          0.803      0.862
Item 4      1.864           0.621          0.774      0.837
Item 5      1.702           0.567          0.887      0.959
Item 6      2.709           0.903          0.463      0.642
 
    * Item difficulty is the ratio of mean score to possible maximum score 
      and assumes the minimum score is 0 
 
 
           RESPONSE CATEGORY SELECTION PROPORTIONS 
 
           0     1     2     3
Item 1 0.161 0.189 0.375 0.274
Item 2 0.200 0.263 0.275 0.262
Item 3 0.240 0.330 0.242 0.188
Item 4 0.114 0.206 0.384 0.297
Item 5 0.189 0.191 0.351 0.270
Item 6 0.021 0.026 0.176 0.777
 
 
 
      RESPONSE CATEGORY Point-Biserial Correlation 
 
            0      1      2     3
Item 1 -0.656 -0.308  0.128 0.672
Item 2 -0.627 -0.191  0.180 0.579
Item 3 -0.688 -0.077  0.269 0.550
Item 4 -0.543 -0.332  0.073 0.593
Item 5 -0.682 -0.272  0.154 0.677
Item 6 -0.272 -0.188 -0.289 0.430
 
 
            RESPONSE CATEGORY Biserial Correlation 
 
            0      1      2     3
Item 1 -0.987 -0.446  0.164 0.900
Item 2 -0.896 -0.258  0.241 0.782
Item 3 -0.946 -0.101  0.368 0.797
Item 4 -0.895 -0.471  0.093 0.783
Item 5 -0.988 -0.393  0.198 0.909
Item 6 -0.770 -0.499 -0.425 0.600
 
 
 
> 
> item.analysis$plots[[1]]   # Item Trace Line for the first item
> 
> # item.analysis$plots[[2]]   # Item Trace Line for the second item
> # item.analysis$plots[[3]]   # Item Trace Line for the third item
> # item.analysis$plots[[4]]   # Item Trace Line for the fourth item
> # item.analysis$plots[[5]]   # Item Trace Line for the fifth item
> # item.analysis$plots[[6]]   # Item Trace Line for the sixth item
> 
> 
> 
> 
> 
> 
> dev.off()
null device 
          1 
>


Created & Maintained by Osamu Ogasawara (osamu.ogasawara@gmail.com) and IMSBIO