IRTpp (version 0.2.6.1)

information: Test or Item information

Description

Computes the amount of test or item information.

Usage

information(object, range, items = NULL)

Arguments

object

a matrix (con los coeficientes estimados)

range

a interval for which the test information should be computed.

items

the items for which the information shoulb be computed.

Value

TotalInfo the total amount of information.RangeInfo the amount of information in the specified interval.RangeProp the proportion of information in the specified interval.Range the value of range argumentitems the value of items argument

Details

The amount of information is computed as the area under the Item or Test Information Curve. The function was adapted from ltm_1.0 package.

References

Reckase, M. (2009). Multidimensional item response theory. New York: Springer.

Baker, F. B., & Kim, S. H. (Eds.). (2004). Item response theory: Parameter estimation techniques. CRC Press.

Examples

#data <- simulateTest(model = "2PL", items = 20, individuals = 800) 
#fit <- irtpp(dataset = data$test,model = "2PL")
#fit <- parameter.matrix(fit$z)
#information(fit, c(-2, 0))
#information(fit, c(0, 2), items = c(3, 5))