Every year, the NBME publishes performance data for each of the exams. You can view excerpts of performance data here.
Score Interpretation Guidelines
The USMLE Score Interpretation Guidelines provide score interpretation information for Step 1, Step 2 CK and Step 3 examinations.
Comprehensive Review of USMLE
The Composite Committee, which establishes policies for the USMLE program, initiated the Comprehensive Review of USMLE (CRU) in January 2004. This multiyear review has led to a series of modifications to test content representation, to changes in a number of existing test formats, and to developmental efforts intended to expand the types of competencies addressed by USMLE.
Invitational Conference on USMLE Scoring (INCUS)
USMLE-related publications from 2017--2009 are available.