Increase of Uncertainty in Summed-Score-Based Scoring in Non-Rasch IRT.

ABSTRACT: Summed-score (SS)-based scoring in non-Rasch IRT allows for pencil-and-paper administration and is used in the Patient-Reported Outcomes Measurement Information System (PROMIS) alongside response-pattern-based scoring. However, this convenience comes with an increase in uncertainty (the increase) associated with SS scoring. The increase can be quantified through the relationship between Bayesian SS and RP scoring. Given an SS of s, the SS posterior is a weighted sum of RP posteriors, with weights representing the marginal probabilities of RPs. From this mixture, the SS score (SS posterior mean) is a weighted sum of RP posterior means, and its uncertainty (variance of the SS posterior) is decomposed into the uncertainty of RP scoring (the weighted sum of RP posterior variances) and the incr

SUBMITTER: Segawa E 

PROVIDER: S-EPMC12162545 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature