“Items are administered following the principles of computer adaptive testing (CAT). Candidates are NOT randomly selected to receive a designated number of examination items. As a candidate takes the examination, questions are selected based on the candidate’s response to previous questions. Testing stops when it can be determined with 95% confidence that a candidate’s performance is either above or below the passing standard, regardless of the number of items answered or the amount of testing time elapsed (six-hour maximum time period for the NCLEX-RN examination and five hour maximum time period for the NCLEX-PN examination).”

hope this helps!