Read ConQuest ‘itanal’ Output Files

Reads Conquest files comprising item analyses generated by the itanal statement.

get.itn(file)

Arguments

file

Character string with the name of the Conquest item analysis file.

Value

A data frame with 18 columns:

item.nr

Number of the item in the analysis

item.name

Name of the item

Label

Response category label

Score

Score of this response category

n.valid

Total number of students who responded to this item

Abs.Freq

Number of students who gave this response

Rel.Freq

Number of students who gave this response as a percentage of the total number of respondents to the item

item.p

Percentage of students who answered this item correctly

diskrim

Item discrimination

pt.bis

Point-biserial correlation for this response

t.value

T-Value of the significance test whether the point-biserial correlation is different from 0

p.value

p-Value of the significance test whether the point-biserial correlation is different from 0

PV1.Avg.1

Mean ability (in the first latent dimension) of students who gave this response (based on plausible values)

PV1.SD.1

Standard deviation of ability of students who gave this response (based on plausible values)

threshold

Item threshold

delta

Item delta

If the model is multidimensional, the mean and standard deviation of the ability of students who gave the respective response will be shown for each dimension.

References

See pp. 193 of Wu, M.L., Adams, R.J., Wilson, M.R., & Haldane, S.A. (2007). ACER ConQuest Version 2.0. Generalised Item Response Modeling Software. Camberwell, Victoria: ACER Press.

Examples

file <- system.file("extdata", "twodim.itn", package = "eatModel")
if (nzchar(file)) {
itn  <- get.itn(file)
}