checkStopRules {catSurv}R Documentation

Check if Stop and/or Override Rules are Met


Evaluates the specified stopping and/or override rules to check if respondent should be asked further questions.





An object of class Cat


The stopping rule thresholds are stored in the following Cat object slots: lengthThreshold, seThreshold, infoThreshold, and gainThreshold. The override thresholds are stored in the following Cat object slots: lengthOverride, gainOverride. A value of NA indicates the rule will not be used in evaluating if further questions should be administered. A user can specify any combination of stopping rules and/or overrides.

Stopping Rules:

lengthThreshold: Number of question's answered \geq a

seThreshold: SE(\hat{\theta}) < a

infoThreshold: FI < a \forall remaining items

gainThreshold: SE(\hat{\theta}) - \sqrt{EPV} | < a \forall remaining items


lengthOverride: Number of question's answered < a

gainOverride: |SE(\hat{\theta}) - \sqrt{EPV} | \geq a \forall remaining items


The function checkStopRules returns a boolean. TRUE indicates all specified stopping rules are met and no specified overrides are met. No further items should be administered. FALSE indicates at least one specified stopping rule is not met, or if any specified override threshold is met. Additional items should be administered.


This function is to allow users to access the internal functions of the package. During item selection, all calculations are done in compiled C++ code.


Haley Acevedo, Ryden Butler, Josh W. Cutler, Matt Malis, Jacob M. Montgomery, Tom Wilkinson, Erin Rossiter, Min Hee Seo, Alex Weil


Babcock, Ben, and David J. Weiss. 2009. “Termination Criteria in Computerized Adaptive Tests: Variable-Length CATs are not Biased." Proceedings of the 2009 GMAC Conference on Computerized Adaptive Testing. Vol. 14.

See Also

Cat-class, estimateSE, expectedPV, fisherInf


## Loading ltm Cat object

## Store example answers
setAnswers(ltm_cat) <- c(1,0,1,0,1,0,0,0,1,1, rep(NA, 30))

## Stop administering items if standard error of ability
## estimate is low enough
setSeThreshold(ltm_cat) <- .5

## Now stop if standard error is low enough, but only if respondent has
## answered 11 questions 
setLengthOverride(ltm_cat) <- 11

## When respondent has answered 11 questions and standard error
## of ability estimate is below .5, stop administering items
setAnswers(ltm_cat) <- c(1,0,1,0,1,0,0,0,1,1,0, rep(NA, 29))

[Package catSurv version 1.4.0 Index]