A lawsuit alleging racial discrimination in Harvard University's admissions process is heading to trial in Boston's Federal Court.

The group Students for Fair Admissions has accused the Ivy League school of bias against Asian-American applicants, saying it holds them to a higher standard than students of other races.

Harvard denies any discrimination and says it considers race as one of many factors when considering applicants.

Both sides will present their cases to U.S. District Judge Allison D. Burroughs starting today.

The lawsuit was filed in 2014 and carries implications for many other U.S. colleges that say they consider race to admit a diverse mix of students.

The case already has pulled back the curtain on aspects of Harvard's secretive admissions process, including a "personal rating" that measures certain character traits.

A look at the case and what to expect:

Who's involved

Students for Fair Admissions is a non-profit led by Edward Blum, a legal strategist who argues schools should not consider race in admissions. The group is based in Arlington, Va., and says it has more than 20,000 members, including at least some Asian-Americans who were rejected from Harvard.

Affirmative action activist Edward Blum, founder of Students for Fair Admissions (SFFA), speaks to reporters at Sunday's rally. (Brian Snyder/Reuters)

Blum previously helped co-ordinate a lawsuit accusing the University of Texas of discriminating against white students. The U.S. Supreme Court heard the case and upheld the school's consideration of race in 2016.

Harvard, one of the nation's most selective colleges, is defending the "holistic" review process it uses to pick from thousands of applicants a year. It considers factors from grades to geography, but also race, a tricky topic for a school that has struggled to reflect the nation's growing diversity.

Harvard says it has made strides in that area but must be able to consider race in order to continue progress.

The main arguments

The lawsuit accuses Harvard of imposing tougher standards for Asian-American applicants and says it discriminates against them using a "personal rating" category.

It also alleges Harvard practises "racial balancing," saying the school works to maintain a certain distribution of each race on campus, which in past cases was ruled unconstitutional.

Officials at Harvard University, shown in this March 17, 2017, file photo, are likely to point to the rise in Asian-American students through the years in their defence. (Charles Krupa/Associated Press)

The group's case partly relies on an analysis of Harvard admissions records by Duke University economist Peter Arcidiacono, who found that Asian-Americans bring the strongest academic records but are admitted at the lowest rate. He also found that while Asian-Americans receive strong personal rating scores from alumni interviewers, they are consistently dealt lower scores in that area from the admissions office.

Harvard denies the accusations and says the group has failed to provide any concrete evidence of discrimination. University leaders say race is considered only in the narrow way that has been upheld in earlier Supreme Court cases, and they note that Harvard's share of Asian-Americans has grown in recent years, reaching 23 per cent of the current freshman class.

School officials see the lawsuit as an attack on their ability to build a diverse campus, and vowed to defend the consideration of race for schools across the U.S.

Their defence partly relies on an analysis by David Card, an economist at the University of California, Berkeley, who found no evidence of discrimination in Harvard's admissions records.

What's at stake?

The case follows a series of previous lawsuits challenging whether colleges can consider the race of applicants, a practice that generally has been upheld. Dozens of schools continue to factor race into admissions and will closely watch to see if their own practices are deemed fair or could be put into jeopardy.

For observers, the case is expected to shine a light on Harvard's closely guarded admissions process. The judge allowed Harvard to redact many details from court documents, but they could be uncovered in trial testimony. There could be new revelations, for example, about preferences Harvard gives to children of alumni or donors, and a so-called "Z-List" that offers deferred admission to certain students who don't get in through the typical process.

Ultimately, Harvard believes its campus diversity is at stake and says it couldn't achieve a rich mix of students without considering race. Its leaders also believe the suit threatens the flexibility that other courts have granted schools to build the type of student population that's best for their own campus.

Students for Fair Admissions believes the case could fix a system that places unfair weight on race, primarily at the expense of academically talented Asian-Americans. The group's suit demands that Harvard make admissions decisions without any knowledge of students' race, and it asks for a broader ruling that the use of race in education is a civil rights violation.

The case is going to a bench trial, meaning it will be decided by a judge, not a jury. But the case isn't likely to end there. An appeal is expected, potentially setting the stage for another Supreme Court case.