Information Brief 2002-1

Interpreting ACT Assessment Scores

Students, parents, and high school counselors sometimes contact ACT to ask about the meaning of ACT Assessment scores. For example, a student may know that her score is above average, but may not be able to determine whether it is considerably above average or just somewhat above. Another student may simply want to know how his score compares to the scores of other ACT-tested students nationwide. Similarly, a parent may want to know the percentage of students nationwide who earned higher scores than his daughter’s score. This brief is intended to help people answer these types of questions and to interpret ACT scores accurately.

There are two primary ways to interpret ACT scores. The first involves comparing an individual student’s score with the scores of all other ACT-tested students. This is called a “norm-referenced” interpretation. The first three sections of this brief give examples of this type of interpretation. Another way of interpreting ACT scores involves describing specific academic skills and knowledge that a student has likely acquired, given the particular score range in which her or his ACT score lies. ACT’s Standards for Transition (described below) offer this “criterion-referenced” type of score interpretation.

Ranks of ACT Scores

ACT scores range from 1 (low) to 36 (high). A common, norm-referenced way of interpreting an ACT score is by considering the percentage of ACT-tested students nationwide who scored at or below that particular score. This percentage is sometimes called a “percent at or below” or a “cumulative percent.” In this brief, the phrase “percent at or below” (PB) is used.1 PBs offer a way to determine the relative standing of a particular ACT score. For example, an ACT Composite score of 23 earned during the 2001–2002 testing year has a PB of 70. This means that 70% of the 1,069,772 ACT test takers who expected to graduate from high school in the spring of 2001 earned a Composite score of 23 or lower. Moreover, because its PB is larger than 67, a score of 23 is among the top one-third of scores nationwide. Subtracting the PB from 100% provides another way to interpret a score: In this case, 30% (100%–70%) of the 2001 graduates scored higher than 23.

Frequently and Infrequently Earned Scores

When interpreting an ACT score, it can be useful to know whether it is a frequently (or infrequently) earned score. Suppose, for example, that a student earns a Composite score of 20. This is a common score: Among the ACT-tested 2001 high school graduating class (1,069,772 students), 86,198 students earned Composite scores of 20. We can therefore determine that out of approximately every 12 students who took the ACT, one of them earned a 20 (1,069,772 divided by 86,198 is approximately equal to 12). Table 1 shows the number of students earning other ACT scores. Note that relatively few students earned scores near the ends of the score scale. For example, one of every 12,020 students who took the ACT earned a Composite score of 36.

Table 1
Number of
students who
earned score
One of every
___ students
earned score
36 89 12,020
34 2,499 428
32 8,849 121
30 19,374 55
28 32,727 33
26 48,208 22
24 65,250 16
22 78,650 14
20 86,198 12
18 79,636 13
16 62,138 17
14 38,177 28
12 13,641 78
10 1,092 980
8 70 15,282
6 11 97,252

Comparisons to the Average ACT Score

Another norm-referenced way of interpreting an ACT score is to determine how close it is to the national average ACT score. For example, the average ACT Composite score for the 2001 graduating class (the “national” average) is 21.0. The corresponding standard deviation, a measure of how the scores vary around the average, is 4.7.2 We know from statistical theory that about 95% of students will score within plus or minus 2 standard deviations of the average Composite score; i.e., between about 12 and 30.3 Therefore, scores that are more than two standard deviations away from the average are fairly uncommon. A Composite score of 23, for example, is less than one-half standard deviation above the average score, suggesting that it is above average, but not unusually so. Note that this method of interpretation also applies to scores earned in other testing years. For example, we can use the average ACT score and standard deviation for the 2000 high school graduating class to evaluate an ACT score earned during the 2000–2001 testing year.

Standards for Transition

ACT's Standards for Transition offer yet another means of interpreting ACT Assessment scores. The Standards are descriptions, based on students’ ACT Assessment performance, of the academic knowledge and skills that students have likely acquired. For example, the mathematical skills of a student who is in the 20–23 score range on the ACT Mathematics test will likely include (but are not limited to) solving rate and proportion problems, determining probabilities of simple events, demonstrating knowledge of the concept of absolute value, manipulating basic algebraic expressions, and solving first-degree equations.

The Standards were developed by content area experts and nationally recognized scholars from high schools and universities who determined the knowledge and skills needed to correctly answer test questions corresponding to various score ranges. The Standards can be used to help students identify knowledge and skills that will better prepare them for future education, and to help teachers and other educators learn more about their students’ academic strengths and weaknesses.

College Admissions

Students, parents, and high school educators are not the only people who interpret ACT scores. College and university admission officials also interpret these scores when deciding whether to admit students to their respective institutions. These officials generally consider admissions test scores together with other information such as high school grade average, class rank, high school course work, and letters of recommendation.4 Indeed, ACT’s position is that test scores are only one element of the admission process, and should be considered only in combination with other measures of academic achievement when making admissions decisions.

Students often wonder whether their ACT scores are sufficient for admission to particular colleges and universities. On the current ACT Assessment Student Report, information is provided about typical ACT Composite averages for colleges and universities with admission policies ranging from open (nearly all high school graduates are accepted) to highly selective (most of those accepted are in the top 10% of their respective high school graduating classes). This information is reproduced in Table 2. Because test scores are only one indicator of college readiness, and because admission policies vary across colleges, the score ranges in Table 2 should be considered rough guidelines. For example, a student with a Composite score of 22 might not be admitted at any of the selective institutions to which he or she applies. On the other hand, a student with a Composite score of 21 and exceptional high school grades and letters of recommendation might be admitted at one or more selective institutions.

Table 2
College admission policy Typical ACT
Highly selective (majority of accepted freshmen in top 10% of high school graduating class) 27–31
Selective (majority of accepted freshmen in top 25% of high school graduating class) 22–27
Traditional (majority of accepted freshmen in top 50% of high school graduating class) 20–23
Liberal (some freshmen from lower half of high school graduating class) 18–21
Open (all high school graduates accepted, to limit of capacity) 17-20

* * * * *

As this brief has shown, we can interpret ACT scores by examining their corresponding PBs, by determining the frequency of their occurrence, by comparing them to national average ACT scores, and by using the Standards for Transition. In addition, the meaning of ACT scores depends on college admission policies, and on how colleges use the scores together with other information about academic achievement.

1. See PBs for each possible ACT score.

2. See ACT Assessment averages and standard deviations.

3. Similarly, we know that about 68% of students will score within plus or minus one standard deviation of the average score.

4. Breland, H. R., Maxey, J., McLure, G. T., Valiga, M. J., Boatwright, M. A., Ganley, V. L., & Jenkins, L. M. (1995). Challenges in college admissions; report of a survey of undergraduate admissions policies, practices, and procedures. Washington, DC: American Association of Collegiate Registrars and Admissions Officers.