Computerized Adaptive Testing (CAT)
The algorithm adjusting NCLEX item difficulty to measure ability
Definition
Computerized Adaptive Testing (CAT) is the psychometric algorithm used on the NCLEX that adjusts question difficulty based on the candidate's previous responses. It identifies true ability level with fewer items than a fixed-length test.
How CAT Works
- Initial item at medium difficulty
- Correct answer → slightly harder next item
- Incorrect answer → slightly easier next item
- Algorithm narrows estimate of ability level
- Exam ends when 95% confidence of pass/fail is reached, or maximum items, or time limit
Exam Length Ranges
- NCLEX-RN: 70 to 135 items
- NCLEX-PN: varies similarly
Implications
Receiving harder questions is NOT a sign of failing. It may indicate strong performance. Focus on each question individually; don't rush.
NCLEX Relevance
Understand CAT to manage test-day anxiety.