reliabilityIRT {petersenlab}

Reliability (IRT).

Description

Estimate the reliability in item response theory.

Usage

reliabilityIRT(information, varTheta = 1)

Arguments

information

Test information.

varTheta

Variance of theta.

Details

Estimate the reliability in item response theory using the test information (i.e., the sum of all items' information).

Value

Reliability for that amount of test information.

See Also

https://groups.google.com/g/mirt-package/c/ZAgpt6nq5V8/m/R3OEeEqdAQAJ

Other IRT: discriminationToFactorLoading(), fourPL(), itemInformation(), standardErrorIRT()

Examples

# Calculate information for 4 items
item1 <- itemInformation(b = -2, a = 0.6, theta = -4:4)
item2 <- itemInformation(b = -1, a = 1.2, theta = -4:4)
item3 <- itemInformation(b = 1, a = 1.5, theta = -4:4)
item4 <- itemInformation(b = 2, a = 2, theta = -4:4)

items <- data.frame(item1, item2, item3, item4)

# Calculate test information
items$testInformation <- rowSums(items)

# Estimate reliability
reliabilityIRT(items$testInformation)