After taking the SAT or ACT, some students embark on a test prep program to try and improve their scores. But many families wonder exactly what kind of score improvement they can expect following test prep.

Lisa Bleich, president of College Bound Mentor and author of Surviving the College Application Process, usually tells her students that "their improvement is directly related to how much energy they spend studying, how many practice tests they take and understanding which test suits them better based on timing and complexity of the questions. Many students can improve on average 150 to 200 points on the SAT and three to five points on the ACT with hard work and tutoring."

What Should You Do to Ensure Improvement?

The first step in working toward a higher score is figuring out what is standing in the way of improving your score.

Experiencing test anxiety? Take a lot of practice tests in a simulated setting to boost your confidence and help you feel less anxious. If you're reading too slowly, then focus your test prep on learning the strategies to extract the information you need to answer the questions. When it comes to improving your reading comprehension, Bleich recommends brushing up on grammar and reading plenty of non-fiction or magazine articles of various subjects. Most tutors can help students understand their weaknesses, she adds.

However, to keep your expectations in check, it's important to be realistic about how much better your score can actually get. Simply spending more time on test prep won't necessarily correlate to a bigger improvement in your score. The possibility of a higher score will depend on what the obstacle is. Bleich points out that if you are having problems with pacing, then it may be "more difficult to improve on the ACT because part of the challenge of that test is being able to move quickly through the questions since you get less time per question. If a student has a hard time doing calculations without a calculator, then perhaps that section of the SAT will be harder to improve."

Also, there is a point of diminishing returns after a certain amount of testing. "I've seen some students do better and others fall off in subsequent tests. However, I also see some students who do better after taking a break the summer between junior and senior year and then improve on the fall senior year tests," says Bleich.

Just be sure to take the practice version of the SAT and the ACT before you register for your first test -- you need to know from the very start which test is a better fit for your strengths. And this way, Bleich says you can focus your test prep on only one test instead of switching to the other exam if you aren't happy with your first test performance.