My school, like many colleges, has special accommodations for those with attention deficit disorder (ADD ADHD) and other learning differences.
A testing center is set up to provide extended time and other helpful arrangements. More often than not, I would rather take the test with the other students in my class. This, however, may lead to failure, loss of financial aid, probation, disenrollment, and, ultimately, spending my life under a bridge. So I force myself to schedule a time at the testing center to take my tests.
It is not easy to approach a teacher, in high school or college, to ask for accommodations in testing. I, personally, would rather ask them their preference in deodorant.
I often outline my "plan of approach" before actually, well, approaching. So many teachers are unaware of the real disability experienced by someone with ADHD, and just don't see the need for accommodations.
"You should take the test with everyone else," "I don't understand why you get an advantage over other students," "Why should I bend over backward for one student?" "I never had extended time when I was in school," or, my favorite, "I'm only doing this because I'm required to by law." I've heard it all and, clearly, I am not the most popular student in some of my classes.
Some teachers don't understand ADHD, and they don't want to learn about it. My dad says forgive them, for they know not that they know not. Once you have lived with someone who has ADHD, your view of it changes radically. I'm confident that many of my professors are simply one child or grandchild away from understanding -- and appreciating -- the extra burden carried by a student with ADHD.
Despite my carefully plotted approach plan, because I am afraid of some authority figures, I tend to forget what I've planned to say. The cogent arguments I have built into my presentation dwindle away after the first sentence. This, along with just plain forgetting to talk to the teacher at all, has been my downfall on more than one occasion.
Even when I have written a reminder to myself in my assignment book... I forget. The last five minutes of class cast a spell over me, and I focus solely on getting the you-know-what out of there. If I have not written a reminder on my hand, I return home, sit down, and think "D'oh!" Thankfully, e-mail has turned out to be my personal savior. If I have forgotten to approach a professor -- or am too chicken to have that conversation with an especially forbidding one -- I simply go to the information superhighway and hit the Send button (no stammering, no preparation, no forgetting).
It is also a good idea to ally yourself with the counseling service, or whatever office your school provides to students qualified for accommodations. If I have trouble with a teacher, I know where to go for guidance... and maybe even for some advocacy with an indifferent teacher.