Item difficulty
Explore how item difficulty changes with different patterns of correct and incorrect responses.
Discrimination
Observe how an item differentiates among respondents with different levels of performance.
Point-biserial correlation
Examine the relationship between a dichotomous item response and the total test score.
Option analysis
Visualise how the correct option and distractors function across different performance groups.
Differential item functioning (DIF)
Explore the Standardized P-Difference and observe how focal/reference group differences vary across performance strata.
Reliability and precision
Explore split-half reliability, Spearman–Brown, KR-20, Cronbach's alpha and the standard error of measurement (SEM).
Item Response Theory (IRT)
Explore item characteristic curves, item information, standard error and how test functioning changes as different items are selected.
Stocking–Lord equating
Explore how anchor items are used to estimate A and B, transform item parameters, equate forms and establish score equivalents.