I personally consider questions to be have a higher level of difficulty when there's multiple steps involved. For calculation questions I've gotten on the first testlets of the exam, you had to know what you were doing but they were fairly straightforward and you just had to plug the correct numbers into the correct formula and you're at your answer. For testlets I considered to be “difficult,” the calculation questions were much more involved and required applying multiple formulas and anywhere from 3-5 steps beyond the calculation questions found in the first testlet.
I could be entirely off base here but I do know that on my first attempt at FAR the level of involvement in determining the correct answer in each calculation MCQ was roughly the same throughout the three testlets and for the exam I took yesterday the second and third testlets contained MCQs that required significantly more effort on my part simply because I had to work through several different calculations to arrive at the answer. Not that I didn't occasionally get those types of problems in the first testlet, but there were MANY more of them in the second and third testlets.
Now, for BEC, REG, and AUD, I really didn't notice any difference in any of my testlets. Maybe the MCQs in REG got a bit more lengthy, but I was honestly paranoid after those exams because I thought they were all pretty similar. My second attempt at FAR yesterday was really my first exam where, once I got through the first 5 MCQs in the second testlet, I was internally freaking out because they were taking much longer to get through than the MCQs on the first testlet. They also completely killed the happy mood I was in when I hit “Continue Exam” at the end of the first testlet because I didn't have too much trouble with the MCQs in that testlet.
However, going against everything I just said, I've looked through some of the AICPA released questions in the past that list the level of difficulty with the MCQ and there were definitely more than a few where I thought they had overstated or understated the difficulty level, so in the end it really is all subjective. That's why I decided to go with an increasing frequency in the number of calculation MCQs that take more time to complete even when you know what you're doing. When you have mostly conceptual MCQs, like in AUD, I have no idea what the AICPA terms “medium” versus “difficult.” I wonder if they've ever actually released their criteria for difficulty levels?
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