Information Brief 2001-2

Improving Performance on the ACT Assessment

Not surprisingly, students are concerned about earning the highest score on the ACT Assessment that they possibly can. To a considerable extent, performance on this test depends on students' academic preparation. There are other things that may also affect ACT scores, however. This brief offers several suggestions—for counselors, students, and parents—about what students can do, academically and otherwise, to improve their performance on the ACT.

Take More College-Preparatory Core Courses

The ACT measures educational development in the areas of English, mathematics, reading, and natural sciences. The more college-preparatory core courses that students take in these areas, the more likely they are to earn the highest ACT scores that they possibly can.

Just how much of a difference does college-preparatory course work make? In one study, for example, the ACT scores and course taking data for nearly 74,000 students representing about 1,200 high schools were studied.1 It was found that students who took trigonometry earned ACT Mathematics scores that averaged almost 1-1/2 scale score points higher than those of students who did not take trigonometry.2 For Science Reasoning, the average score difference associated with taking trigonometry was about 1/2 scale score point. Students who took calculus earned Mathematics scores that averaged about 1-1/4 points higher than those of students who did not take calculus.Chemistry or physics course taking was associated with an average score difference of about 1/2 point in Science Reasoning. Taking any one of these courses was associated with an average ACT Composite score difference of about 1/2 point. All these results occurred irrespective of students' gender, race/ethnicity, family income, and tenth-grade achievement test scores.

Another study, based on data from about 5,500 students at 106 schools, suggests that college-preparatory course work may have an even stronger relationship with ACT scores.3 Students who took calculus, for example, scored an average of about 3-1/2 points higher on ACT Mathematics, 2 points higher on Science Reasoning, and 2-1/2 points higher on the Composite than did students who did not take calculus. This occurred irrespective of students' high school grades and background characteristics.

When interpreting these results, it is important to consider that they represent average score differences associated with taking certain science and mathematics courses. This suggests that some students in these studies experienced either larger or smaller score differences than those reported here.

Take Practice Tests

A simple and effective way to become familiar with the format and content of the ACT is to take a practice test. Results of recent research indicate an association between taking practice tests and increased ACT scores.4 In a group of about 69,000 students, those who reported spending two or more hours taking practice tests prior to taking the test the first time earned ACT Composite scores that averaged almost 1/2 scale score point higher than the scores of those who did not take practice tests. This occurred irrespective of students' high school GPAs and grade levels. In addition, the score increases were fairly similar across gender, race/ethnicity, and family income groups.

Answer Every Question

There is no penalty for "guessing" on the ACT. Students are encouraged to answer every question, even if they are not quite sure of the correct answer.

There are different types of guessing behavior on tests. Guessing can be random, for example. A student may have no idea of what the correct answer is, so he or she just selects at random one of the possible responses that are provided. On the other hand, guessing can be methodical. For example, a student may know enough about a particular question to eliminate one or more possible responses before choosing one of the remaining responses.

Having such partial knowledge of a question increases a student's chances of getting it correct. Consider, for example, a question having four possible responses (A, B, C, and D). If a student knows that B and D cannot be correct, then the correct answer will be either A or C. In this instance, the chances of getting the question correct are one-in-two (rather than one-in-four, as would occur with random guessing).

When the correct answer to a question on the ACT is not known, a good strategy for dealing with the question is first to see if some of the possible responses can be eliminated based on partial knowledge. Then, select one of the remaining responses.

Review Additional Test-Taking Strategies

There are additional test-taking strategies for the ACT, such as reading each question thoroughly, and making sure that only one of the possible responses for each question has been marked. Test-taking strategies and practice tests are provided in ACT's free publication Preparing for the ACT Assessment; in our preparatory guide Getting Into the ACT, available through local booksellers; and in our test preparation software ACTive Prep, which can be ordered through our website. A unique feature of ACTive Prep is that it can develop a customized test preparation plan for each student, based on results from its built-in placement test or on scores from a prior administration of the ACT.

Take the ACT Again

If students are not satisfied with their performance on the ACT, they might consider taking it again, particularly if they have taken additional college-preparatory course work since taking the test the first time.

ACT staff have studied the test performance of students who take the ACT Assessment more than once.5 We know, for example, that students who take the ACT a second time increase their Composite scores, on average, by about one scale score point. Keep in mind, however, that some students will experience larger increases than this, and some will even experience decreases due to a variety of unanticipated circumstances, such as not feeling well during the second test or testing in a noisy environment.

ACT research shows that several things are related to increased ACT Composite scores on a second testing. These include taking the ACT for the first time in 11th grade, taking college-preparatory course work, and earning high grades in high school courses.

If students plan to take the ACT again, it may be helpful for them to look at their current score reports to identify relatively weak areas for additional study and review. The "percents at or below"6 (PBs) that correspond to the scores are useful for identifying areas of strength and weakness. For example, consider a student who took the ACT during the 2000–2001 testing year and earned the following Mathematics subscores:

Subscore area Subscore PB
Pre-Algebra & Elem. Algebra 13 76
Algebra & Coordinate Geometry 12 78
Plane Geometry & Trigonometry 12 73

The PBs indicate that this student's strongest mathematics area is Algebra & Coordinate Geometry (PB = 78); Plane Geometry & Trigonometry is a relatively weak area (PB = 73). If the student were to test again, refreshing her or his plane geometry and trigonometry skills beforehand might be helpful.

The subscores in this example suggest that the student's strongest mathematics area is Pre-Algebra & Elementary Algebra (score = 13). However, the ACT scale scores were not designed to compare performance in different areas; PBs should be used instead to compare performance.

Solid academic preparation is the key to successful performance on the ACT. As this brief has described, however, there are some other things to consider, including familiarity with the format and content of the ACT, test-taking strategies, and retesting.


1Schiel, J., Pommerich, M., and Noble, J. P. (1996). Factors associated with longitudinal educational achievement, as measured by PLAN and ACT Assessment scores (ACT Research Report No. 96-5).

2A scale score is a conversion of the number of correctly answered questions (the raw score). Scale scores range from 1 to 36 for English, Mathematics, Reading, Science Reasoning, and the Composite. They range from 1 to 18 for the subscores.

3Noble, J., Davenport, M., Schiel, J., & Pommerich, M. (1999). Relationships between the noncognitive characteristics, high school course work and grades, and test scores of ACT-tested students (ACT Research Report No. 99-4).

4ACT Assessment Technical Manual (1997), pp. 48-51.

5Two ACT research reports have been published on this topic: [1] Lanier, C. (1994). ACT Composite scores of retested students (Research Report No. 94-3). [2] Andrews, K. M. & Ziomek, R. L. (1998). Score gains on retesting with the ACT Assessment (Research Report No. 98-7).

6On the current ACT student report, a "percent at or below" is called a "rank" or a "percent of college-bound students at or below your score."