Bad idea #3: Taking the test with no prep.
"My son took the August SAT just to see how he'd do."
Taking a test with zero prep can be discouraging, since the material and timing are unfamiliar. And the score in that situation isn't very diagnostic.
The PSAT your kid took sophomore year can be a diagnostic tool - or better yet, she can take an official SAT or ACT in a library study room - for free. Ideally, someone like us would introduce both tests to her first, so she's not thrown off by the material.
We hold proctored practice tests at our office, too. No need to take the real thing to get a baseline score.
Bad idea #4: Using third-party practice tests.
Another bad thing about companies like Kaplan and The Princeton Review is that they write their own practice tests. This is more profitable for them than licensing official SAT / ACT material. But official material is mind-bogglingly more carefully developed. We only use official practice tests for that reason.
In a recent official ACT blog, I learned that each test question undergoes 16 different audits to make sure it's consistent and fair. 16! I know from experience that the person writing the practice question for a company like Kaplan is the most likely the only person who will check - or care about - that question's validity. As a result, questions from companies like Kaplan are often maddeningly inconsistent and not very similar to official SAT and ACT questions.
Bonus Bad: When companies use their own tests, they sometimes give students an unrealistically difficult diagnostic test to make it seem like the kid needs tons of tutoring. And then everyone's happy when the student "improves" by a lot of points on the real test.
Tip: If the program insists that you take a diagnostic test at their facility, this could be why.
Bad idea #5: Starting too late.
Taking the SAT / ACT for the first time in the late summer / early fall is a good idea for most kids, since they can use the relatively calm summer to get a lot of prep done. Then, if needed, they can prep again for a test in, say, the spring.
If someone waits until mid-junior year to deal with test prep, they'll have to work on the tests at the same time they're busy with school and all that that entails. Even if someone hasn't taken all the math that's tested, they can still make a lot of progress - and master a lot of the necessary skills - by taking the August SAT or September ACT.
At the very latest, most students should take an SAT or ACT by spring of junior year - but again, probably sooner. As you may know, most kids take the test 2 or 3 times before they're done.
The Bottom Line
Before deciding on an important - and expensive - service like SAT and ACT prep, consult with a real expert. Matt, Blake, Kaitlin, and I have all been doing this for many years and are happy to help.