standardErrorIRT {petersenlab} | R Documentation |
Estimate the standard error of measurement in item response theory.
standardErrorIRT(information)
information |
Test information. |
Estimate the standard error of measurement in item response theory using the test information (i.e., the sum of all items' information).
Standard error of measurement for that amount of test information.
Other IRT:
discriminationToFactorLoading()
,
fourPL()
,
itemInformation()
,
reliabilityIRT()
# 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)