Relating ACT and SAT scores is a difficult problem. The fundamental difficulty is that the two test batteries measure somewhat different educational constructs. The ACT tests are curriculum-based tests of educational development. Their content is intended to be representative of knowledge and higher-order thinking skills that are explicitly taught in typical college-preparatory programs and that are essential for success in college. The ACT measures academic achievement in the areas of English, mathematics, reading, and science. The SAT, in contrast, measures reading, writing and mathematical reasoning, and is less closely linked to high school and college curricula. Because the ACT and SAT are not parallel in content, and different students have different strengths and weaknesses, there is really no such thing as an equivalent score on the two tests.
From a methodological standpoint, it is preferable to interpret and to use ACT and SAT scores separately. However, many institutions cannot develop and maintain separate systems; they must instead find a comparable score using concordance tables.
Concordant scores are defined as those having the same percentile rank with respect to the group of students used in the study. The tables are useful for determining the cutoff score on one test that results in approximately the same proportion of students selected by the other test (although not necessarily the same students). The table shows, for example, that an ACT Composite score of 20 has a concordant SAT CR+M score of 950; these scores would typically result in selecting approximately the same proportion of students. Use of the concordance tables to estimate individual student performance will provide comparable scores that are less accurate than would estimates based on other statistical procedures. If these tables are used for course placement decisions, then the contents of both tests need to be evaluated carefully relative to the content of the course of interest. Differences between course and test content could result in incorrect placement decisions.
Concordant ACT and SAT scores may vary significantly across students and colleges. Students included in this study are not necessarily representative of the students at a particular institution. Because of this, an institution might wish to investigate the relationship between ACT and SAT scores of its students. For institutions where this is not possible, the concordance tables should provide useful approximations, provided the relevant characteristics of their applicants do not differ greatly from the sample upon which the concordance was developed.
ACT information can be a valuable tool in admissions and orientation, course sectioning and student placement, allocation of financial aid and scholarships, advanced placement and credit by examination, academic advising, student retention and tracking, and other student personnel services. Because of difficulties in estimating individual student performance through concorded values, it is preferable to use actual ACT or SAT scores when possible.