Concordance study by ACT and the College Board
The College Board and the ACT worked together to complete a study of all the students in the high school graduating class of 2006 who took both the ACT and the SAT. The SAT and ACT are different tests, and it is not possible to predict exactly what score a student will get on one test, based solely on the score obtained on the other test. In general, the scores should not be compared. However, we understand that our constituents, particularly members of the admissions community, have a need to assess the test scores of students, some of whom might have taken the SAT, while others might have taken the ACT. A concordance study and the resulting tables, which reflect data from a group of students who have taken both tests, provide the best possible estimated comparison.
What concordance tables show
The SAT has more score points than the ACT, which means it is more accurate to state that a range of SAT scores is concorded to a single ACT score point. However, we know that some of our constituents have a need for a single SAT score point to use with each ACT score point, and we have provided the most accurate estimate we can for this purpose.
How to use the tables
The ACT-SAT tables are based on an entire cohort of students who completed both tests, but this sample is not representative of all ACT or SAT test-takers. The tables, therefore, may not be appropriate for use with scores from students who take either ACT only or SAT only. Overall, a student who receives a score on one test will not necessarily obtain the concorded score on the other test.
From ACT to SAT:
The ACT Composite score does not contain the ACT Writing Test score. For this reason, you will get the most accurate estimates if you use the tables as follows:
- For students who do not take the optional ACT Writing test: Use Table 1 to concord an ACT Composite score to an SAT (CR+M) score on the 400-1600 scale.
- For students who take the ACT Plus Writing: Use Table 1 to concord from the ACT Composite (which does not include ACT Writing) score to the SAT (CR+M) score; use Table 2 to concord from the ACT Combined English/Writing score to the SAT Writing score; then simply add SAT (CR+M) concorded scores and SAT (W) concorded scores to get to the SAT 600-2400 scale.
From SAT to ACT:
- Add the SAT Critical Reading and Mathematics scores together; use Table 1 to concord from the SAT (CR+M) score to the ACT Composite score; use Table 2 to concord from the SAT Writing score to the ACT English/Writing score
Source : http://professionals.collegeboard.com