Originally the Scholastic Aptitude Test, the SAT shed that name years ago along with the devilish antonym and analogy questions that were a staple of what was once called the “verbal” section. It underwent a major change in 2005 that drew mixed reviews.

　　That year, a writing section, worth a maximum 800 points, was added with multiple-choice questions and a 25-minute essay. Critics complained that too little time was given for essay revisions and that writing assignments did not reflect the level of analysis expected in college. Some college admissions officers also were lukewarm.

　　“As a predictor of student success, a 25-minute essay isn’t going to tell us a great deal,” said Stephen J. Handel, associate vice president of undergraduate admissions for the University of California.

　　And in recent years, more and more students were gravitating toward the rival ACT exam. The SAT has long been dominant on the West coast, in the Northeast and in the Washington region. The ACT, launched in 1959 and overseen by an organization based in Iowa, attracts more students in the middle of the country and the South.

　　The two tests overlap in mission but diverge in style and content, with the ACT traditionally measuring achievement (including a science section) and the SAT measuring thinking skills. But the ACT has made inroads on the SAT’s turf, and many students now take both. In 2012, the ACT surpassed the SAT in the number of reported test-takers.

　　Both exams also are facing challenges from the growing test-optional movement. The National Center for Fair and Open Testing lists about 800 colleges and universities that admit a substantial number of undergraduates without requiring them to submit SAT or ACT scores.

　　Among them is American University, which started the experiment in 2010. Now 18 percent of its applicants do not submit SAT or ACT scores.

　　“It’s rising, and it’s gone up every year,” said Sharon Alston, AU’s vice provost for undergraduate enrollment. She said the university has not detected “any significant difference” in the performance of students who don’t submit test scores compared with those who do.

　　College Board officials, mindful of these developments, say the redesign has a larger purpose.

　　“We’re not just chasing market share here, I can assure you that,” said Shirley Ort, a top financial aid official at the University of North Carolina-Chapel Hill, who is vice chair of the College Board’s governing board. “We want the SAT to be more than just an event that takes place in a test center. We think it can serve as a catalyst for student engagement.”

　　The redesign will beef up the essay, giving students who choose to take it 50 minutes to analyze evidence and explain how an author builds an argument. The rest of the test will be three hours. Currently the SAT takes three hours and 45 minutes.

　　The math section will tighten its focus on data analysis, problem solving, algebra and topics leading into advanced math. Calculators, now permitted throughout the math section, will be barred in some portions to help gauge math fluency.

　　The section now called “critical reading” will be merged with multiple-choice writing questions to form a new section called “evidence-based reading and writing.” Questions known as “sentence completion,” which in part assess vocabulary, will be dropped. Analysis of passages in science, history and social studies will be expanded.

　　And each version of the test will include a passage from documents crucial to the nation’s founding, or core civic texts from sources such as President Abraham Lincoln or the Rev. Martin Luther King Jr.

　　When the test probes student vocabulary, the College Board said, it will focus on “words that are widely used in college and career.” Coleman cited “synthesis” as an example. “This is not an obscure word, but one students encounter everywhere,” he said.

　　Choosing such words could prove difficult. Carol Jago, a past president of the National Council of Teachers of English, who serves on a College Board advisory panel, said the test revisions would “reward students who take high school seriously, who are real readers, who write well.” She said she was loath to drop from the exam a word such as “egalitarian,” which appears in one College Board practice test. But she said: “Maybe we can live without ‘phlegmatic.’ ”