I guess that that's the purpose of having "experimental" questions, to progressively adapt the asigned level of dificulty of them. Pure especulation, but I think that as the question is asked in several tests, the level is adapted to that of the test taker.

For example, if you are in the 35-40 and you don't answer correctly to a experimental question, its level is raised to this level. In the same way, if you are in the 30-35 and your answer is ok, the level probably lowered... repeating this process with hundreds of test takers they can have a pretty good idea of the level of one question.

Answering your question, i do not know whether the temporary difficulty level is in fact used, but if i had to guess, i would say so. The GMAT guys probably have fun reading all our thoughts, theories and reverse engieering of their test...

@Derek:
i hope you must have gone through Kevins marathon Series of weekly GMAT feeds...
if you still hv this doubt then heres what i comprehend from his articles...

Dear Derek,
Experimental questions are as you know for GMAC and not for us.
so we have nothing to do with those...
so in simple terms ( & to the point answer: ) the experimetal questions are NOT computer adaptive.

so even if you answer it wrong dont worry....but hey hey you dont know which item is experimental one... there there.... dont trouble

and yes. GMAC will throw experimental questions randomly at you. and trust me they wont influence your future questions as well as your score at all

@Daniel:

: first para: no comments
second para: i agree
third para : lol


Dear Kevin,

just ignore my question that i am going to ask you...
Can you tell us how they put experimental questions in RCs.
If they really do then we can conclude that they repeat the RC passages aslo ...say for at least 2/3 months of period...
right?

Your comments please Mr. Kevin

The experimental questions are used to test the difficulty level of the question. Sometimes they are easy and sometimes they are hard (or impossible to solve). You never know whey you will encounter them, so you have to do your best to answer every question (but if you go longer than 2 or 3 minutes on any question, you need to make an educated guess and move on or you will run out of time before the end and your score will drop).