Definition
Item response theory (IRT)
Item response theory is a statistical framework for modeling how a person's underlying ability relates to their probability of responding correctly to each item. Unlike classical test scoring, IRT accounts for item difficulty and discrimination, producing ability estimates that generalize across different item sets.
Why it matters for HR leaders
It lets an assessment be shorter, adaptive, and fair. Two candidates can see different scenarios and still receive directly comparable scores.
How Leadify uses it
Leadify calibrates each simulation scenario using IRT so ability estimates are stable, adaptive, and directly comparable — the same math that powers GRE, GMAT, and PISA.