petersenlab (version 1.1.0)

standardErrorIRT: Standard Error of Measurement (IRT).

Description

Estimate the standard error of measurement in item response theory.

Usage

standardErrorIRT(information)

Value

Standard error of measurement for that amount of test information.

Arguments

information

Test information.

Details

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

See Also

tools:::Rd_expr_doi("10.1177/0146621613475471")

Other IRT: deriv_d_negBinom(), discriminationToFactorLoading(), fourPL(), itemInformation(), reliabilityIRT(), test_info_4PL()

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)

# Calculate standard error of measurement
standardErrorIRT(items$testInformation)