Preparation for College Admissions Exams: Comparing the SAT and ACT and What They Measure

The SAT

The SAT, developed and administered by The College Board, consists of three principal test sections: Mathematics, Critical Reading1 and Writing. The full exam (in contrast to the ACT, the writing section is not optional) is administered to students across 10 testing sections that span three hours and 45 minutes and 171 unique items. The mathematics section consists of both multiple-choice and constructed-response items, the critical reading section consists solely of multiple-choice items, and the writing section consists of both multiple-choice items and one essay response. Each SAT test section is scored on a scale from 200 to 800 with increments of 10 points. The standard error of measurement associated with the Mathematics and Critical Reading sections is typically about 30 points; the standard error of measurement associated with the Writing section is about 40 points. Like the ACT, SAT scores are reported to students and colleges along with a percentile rank relative to the national distribution of test-takers. As of 2008, the cost of taking the SAT was $45. In 2008, more than 1.5 million students took the exam, and the mean scores on the Math, Critical Reading and Writing sections were 515, 502 and 494 respectively.

What College Admission Tests Measure

Both the ACT and SAT exams are intended to provide measures of a student’s “college readiness.” Superficially, the ways both ACT Inc. and The College Board define what each exam measures are quite similar.

Your ACT scores are a measure of your current level of educational development in English, mathematics, reading, and science—and writing, if you took the ACT Plus Writing. Knowledge and skills in these areas are generally essential for admission to college and are considered important for success in college studies (ACT Inc, Using Your ACT Results 2008/2009, p. 3).

The SAT tests students’ basic knowledge of subjects they have learned in the classroom—such as reading, writing, and math—in addition to how students think, solve problems and communicate. The SAT tells students how well they use the skills and knowledge they have attained in and outside of the classroom (The College Board, The SAT Program Handbook, 2008, p. 1).

There is, however, an important historical distinction between the two exams. In its inception as a tool for college admission in the late 1940s, the SAT was devised as a test of aptitude, and its acronym—the Scholastic Aptitude Test—reflected this belief. Over time, both the format of the test and the position of its developers as to the construct it measures has changed. Messick (1980) and Anastasi (1981) suggested that standardized tests can be conceptualized as solely measuring either achievement or aptitude, and that the SAT falls somewhere in between these two poles. Messick wrote:

The Scholastic Aptitude Test was developed as a measure of academic abilities, to be used toward the end of secondary school as a predictor of academic performance in college… The SAT was explicitly designed to differ from achievement tests in school subjects in the sense that its content is drawn from a wide variety of substantive areas, not tied to a particular course of study, curriculum or program. Moreover, it taps intellectual processes of comprehension and reasoning that may be influenced by experiences outside as well as inside the classroom… The specific item content on the SAT attempts to sample the sort of cognitive skills underlying college-level performance (1980, p. 7).

In contrast, the developers of the ACT have long emphasized the link between the content of its tests of English, math, reading, and science and the high school curricula of American schools. The ACT is curriculum-based. The ACT is not an aptitude or an IQ test. Instead, the questions on the ACT are directly related to what students have learned in high school courses in English, Mathematics and science. Because the ACT tests are based on what is taught in the high school curriculum, students are generally more comfortable with the ACT than they are with traditional aptitude tests or tests with narrower content (www.act.org/news/aapfacts.html).

In other words, with respect to the aptitude-achievement continuum described above, the ACT has always been promoted as an achievement test, and ACT Inc. makes evidence available that supports a link between the content of most college preparatory high school curricula and its tests. Nonetheless, it is worth noting that the scores for corresponding sections of the SAT and ACT exams are both similarly reliable (Alpha coefficient of about 0.9) and tend to be very strongly correlated (between 0.8 and 0.9).