There are three question formats on this step: Single Item, Multiple
Item Sets, and Cases.
The Single Item questions are the standard "multiple
choice" single best answer questions. There are generally
4-5 answers to select from.
The Multiple Item Sets questions are multiple choice,
single best answer questions, all based on a single patient vignette.
Again, each question has a single correct answer (although other
answers may be "partially correct"). The questions are
designed to be answered by themselves - the order in which do
the questions is not important.
The Case-based questions are designed to be answered in
sequential order. Skipping questions can be bad news: the cases
often progress in an orderly fashion, and each question may rely
on information given in preceding questions. Again, these are
multiple-choice, single best answer questions.
For more information on Step 3 question formats visit: http://www.usmle.org/step3/s3tqf.html