The ACT is a standardized test used for college admissions in the United States. It was first introduced in November 1959 by University of Iowa professor Everett Franklin Lindquist as a competitor to the Scholastic Aptitude Test (SAT). It is currently administered by ACT, a non-profit organization.

It is an entrance exam used by most colleges and universities to make admissions decisions. The purpose of the ACT test is to measure a high school student's readiness for college, and provide colleges with one common data point that can be used to compare all applicants.

The ACT contains multiple-choice tests in four areas: English, mathematics, reading and science. ACT's writing test is optional and will not affect your composite score.

The required portion of the ACT is divided into four multiple choice subject tests: English, mathematics, reading, and science reasoning. Subject test scores range from 1 to 36; all scores are integers. The English, mathematics, and reading tests also have sub-scores ranging from 1 to 18 (the subject score is not the sum of the sub-scores). In addition, students taking the optional writing test receive a writing score ranging from 2 to 12 (this is a change from the previous 1–36 score range); the writing score does not affect the composite score. The ACT has eliminated the combined English/writing score and has added two new combined scores: ELA (an average of the English, Reading, and Writing scores) and STEM (an average of the Math and Science scores). These changes for the writing, ELA, and STEM scores were effective starting with the September 2015 test.

Each question answered correctly is worth one raw point, and there is no penalty for marking incorrect answers on the multiple-choice parts of the test; a student can answer all questions without a decrease in their score due to incorrect answers. This is parallel to several AP Tests eliminating the penalties for incorrect answers. To improve the result, students can retake the test: 55% of students who retake the ACT improve their scores, 22% score the same, and 23% see their scores decrease.

Students can evaluate their strengths and weaknesses. Once you’ve taken the test, you can go back over the topics and see what you excel in, and what you might need to work on.

The ACT Assessment Student Report, provides the typical ACT Composite averages for college and universities admission policies. They caution that "because admission policies vary across colleges, the score ranges should be considered rough guidelines." Following is a list of the average composite scores that typically are accepted at colleges or universities.

Highly selective (majority of accepted freshmen in top 10% of high school graduating class): scores 27–30

Selective (majority of accepted freshmen in top 25% of high school graduating class): scores 25–27

Traditional (majority of accepted freshmen in top 50% of high school graduating class): scores 22–24

Liberal (some freshmen from lower half of high school graduating class): scores 18–21

Open (all high school graduates accepted, to limit of capacity): scores 17–20.

How institutions interpret ACT score?

Higher education institutions look at scores to help predict class profiles and overall academic success and to address other factors needed during admissions and enrolments. Here are five examples of ways universities use score reports:

Admissions: ACT test results — along with high school grades, academic preparation, and extracurricular activities — help college admission officers identify which students will thrive at their institution. Scores alone do not determine admission.

Course placement: Colleges usually try to take into account individual strengths and weaknesses as they place students in first-year courses. For example, a college may offer three sections of a subject—developmental, regular, and advanced. A student's results on the ACT, academic background, and high school grades might be used to determine which section would be most appropriate.

Academic advising: College advisors look at ACT results, high school grades and classes, projected college grades, employment plans, and other factors to help students find the perfect fit for their course of study.

Scholarships and loans: Some scholarship and loan agencies may use results from the ACT information such as high school grades to identify qualified candidates. However, the agencies may not look at academic potential alone. The ACT score report provides information about a student's educational needs, extracurricular achievements, and educational plans. This information, along with high school grades and test scores, helps the agencies evaluate applications for scholarships, loans, and other financial assistance.

ACT Writing Test. If students take this optional test, any college that receives their scores will also receive writing scores and comments along with subject area scores and a composite score. Colleges may review students' essays to help them make admissions or course placement decisions.

Challenging the value of high SAT scores: