Students aiming for selective colleges will agonize for days or weeks over every little detail of their applications. But often that file will get just one read, perhaps 5 to 15 minutes, before a gatekeeper decides yes or no.

That is apparent not only from The Washington Post’s observation of George Washington University’s admissions shop, detailed in a story Sunday, but also from interviews with veterans of admissions elsewhere.

“There are some that are open and shut,” said Jon Reider, a former senior admissions officer at Stanford University and co-author of a guidebook called “Admission Matters.”

Reider said the volume of applications at many elite schools — there were about 39,000, for example, at Stanford for a fall 2013 freshman class of about 1,675 — means that admissions officers must triage.

Reider said some files are read once, receive a denial recommendation and are never looked at again. Others get a quick yes on first read, with high ratings of an applicant’s academic potential and personal qualities.

“We called it the jump for joy,” Reider said. When a case was clear-cut, he said, the reader would just “put those through” for a sign-off from the dean of admissions.

To be sure, quite often there are two readers on each application at selective schools. And there are committees to review what the readers have found and render verdicts on borderline cases.

(Disclosure: This reporter was a student long ago in a freshman humanities course Reider taught at Stanford.)

This week many college-bound high school students are waiting for those decisions. Ivy League colleges plan to release theirs simultaneously on Thursday at 5 p.m. Eastern time. The University of Virginia released its decisions on Friday. Georgetown and GW decisions are due out in coming days.

Another point that emerged from the GW story — that files are grouped for reading by high school — also holds true for many other selective colleges, Reider said. Admissions officers at these colleges like to have the fullest possible picture of a high school as they read. Reider said this method enables consistency in judgment as readers evaluate transcripts. “You know what you’re looking at,” he said.

Not all colleges handle it this way.

Here’s what Dartmouth College says on its Web site: “The Admissions Committee does not typically review applications in ‘school groups,’ and therefore we do not directly compare students from a single school to one another. Instead, we try to review applications with the level of competition across the applicant pool in mind.”

Here’s one more point, on what might be called the Quota Question: Admissions officers say over and over, to anyone who asks, that there are no limits on the number of students a college will admit from a given high school.

Parents and students at high-powered high schools might beg to differ, especially when they see that numerous highly qualified students are shut out from an ultra-selective college while one with virtually identical credentials gets in.

Reider, who has seen this issue from multiple perspectives, said he is certain that elite colleges do not have per-school quotas. He’s now director of college counseling for the private San Francisco University High School. Some years, he said, University High scores big with certain colleges. Some years it doesn’t. Georgetown University, he said, has been tough for Reider’s students to get into recently. But he expects several will get offers for Georgetown’s Class of 2018. “This year, it’s really strong,” he said.