If your kid got extra time, how much do you think it added to the score?

For complicated reasons, we didn’t ask for accommodations for DS on the PSAT, but he will almost certainly have them when he takes the SAT or the ACT. Looking at the data, he left about 1/3 of the reading section and a few questions in the math section blank, so I’m thinking that the extra time will help his score, as will some test prep, but I’m curious about how much.

The scores he got weren’t surprising to me, but when I look at the schools we think would be a good fit, another 100 points total would make a significant difference. I’m wondering whether test prep and extended time will be enough or if we should be looking at different schools.

It depends. If the accommodation of extra time is for a processing speed issue then the extra time may help, though I am not sure about a full 100 points. If it is for attention issues, you may see no difference. Extra time without cueing to remain on task doesn’t usually make much difference. You can roughly compare percentile ranks to any past cognitive testing if he has had some, to see how they correlate. Plus or minus 8 percentile rank points is a normal amount of error, so again not that different.

The amount it will change the score will really depend on the student and his/her disability. Can you find a way for your child to do a practice test with the accommodations he expects to get?

We know a student with diagnosed ADD. Her ACT score rose 5 points with extra time. It made a huge difference. The score went from a 19 to a 24.
Getting approval was a major undertaking. She was denied twice, even though they (parents, doc, and GC) submitted extensive documentation. Finally ACT agreed to allow her the time she needed. Start early.