World is a representative sample EXCEPT that there is too high a percentage of internal medicine....I would think medicine is about 40-50% the exam or so on most forms, and the other subjects are more or less in the proportions of world...Obgyn, Peds, and Psych all pretty much have a similar number of questions, so that on any given form one of these topics may be a little overrepresented...On mine I think it was peds, others say obgyn. I think pure surgery related questions might be the least represented, but a fair number of diagnoses have a surgical aspect and so the material overlaps mbetween internal medicine and surgery...Even the surgery shelf exam does not have that many pure surgery questions that could not be asked in a different subject.