itemanalysis2 | R Documentation |
Classical Test Theory Item Analysis for Polytomous Items
itemanalysis2(data, options, ngroup = ncol(data) + 1, correction = TRUE, span.par=.3,verbose=T)
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. |
span.par |
a smoothing parameter to pass to ggplots when creating empirical ICCs |
verbose |
TRUE or FALSE. If it is TRUE, text output is printed. |
to be added later
plots |
a list object storing the item trace line plots for each item |
item.stat |
a matrix of basic item statistics |
dist.sel |
a matrix of distractor selection proportion statistics |
dist.disc |
a matrix of corrected point-biserial statistics for distractors |
dist.disc |
a matrix of corrected biserial statistics for distractors |
Cengiz Zopluoglu
itemanalysis1
for classical item analysis of multiple-choice test items
## Not run: 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 <- itemanalysis2(data=timss2011_usa, options=c(0,1,2,3), ngroup=18, correction=FALSE) item.analysis$item.stat item.analysis$dist.sel item.analysis$dist.disc item.analysis$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 ## End(Not run)
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