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how many counselors should a school have
This 1959 book, known as the Conant Report, is the source of the 250-to-1 student-to-counselor ratio recommendation, according historical research conducted by Harvard graduate student Tara Nicola. (Image from

Schools are commonly advised to hire one counselor for every 250 students. The figure has been recommended and publicized by the American School Counselor Association since 1965. And it’s been frequently used by education lobbyists and advocates to demand more money for schools at state legislatures and in Congress for decades. Some states have the 250 number written into their laws. 

“The 250 number is in almost every piece that you read about school counselors,” said Tara Nicola, a student at Harvard’s Graduate School of Education who is specializing in the field of school counseling. “But there’s never been any empirical evidence for it.”

According to Nicola’s research, the oft-cited number comes from just one 1959 book and it’s not based on any quantitative analysis or experiments to show that students are better off when counselor caseloads approach or fall below 250 students.

I recently came across Nicola’s paper, “Is 250 the Magic Number? The History of the Nationally Recommended Student-to-Counselor Ratio,” when I was writing another story on the growth in school counselors. (Yes, I too cited the questionable 250 number in my story.) Nicola’s research began in the fall of 2019 to fulfill a history class assignment and her paper is now under review for potential publication at an academic journal.

Related: Lowest student-to-school-counselor ratio since 1986

The number 250 began with James Bryant Conant, president of Harvard University from 1933 to 1953, who turned his attention to improving American high schools in the late 1950s. The Cold War was hot, Conant had just returned to the U.S. after an ambassadorship to West Germany and he wanted a rigorous high school education for the masses, not just the elite, as a way to compete against the Soviet Union. At the time, only half of American teens obtained a high school degree. (Think of the era depicted in the musical “Grease.”)

With a $350,000 grant from the Carnegie Corporation, Conant searched for great high schools that were educating the college bound along with those heading for trades and factories. He sought to publicize model schools for the rest of the nation to copy.

Conant’s primary focus was on curriculum but school counseling was also on his radar. According to Conant’s notes, which Nicola read in the Harvard archives, Conant began his project with a 400-to-1 student-to-counselor ratio in mind. That number came from Kenneth Hoyt, an assistant professor of education at the State University of Iowa, who wrote an article in 1955 in the Personnel and Guidance Journal. Hoyt asked the question: “What should be the pupil load for the school counselor?” His answer:  “Nobody knows.” No one had ever conducted an experimental investigation.

Hoyt walked readers through his back-of-the-envelope calculation in a three-page article. Each senior, he opined, should get 115 minutes of counseling. Younger students needed less time. Then he added up all the counseling minutes he thought each student needed and estimated that a single counselor could attend to 400 students if he counseled students during half the working hours available in a school year.  Hoyt was upfront that his list of counselor duties and time estimates were simply his “opinion” and not based on any scientific analysis. 

Conant started with Hoyt’s number of 400 and cut it twice after conducting surveys and school visits.  The first slash, from 400-to-1 to 300-to-1, came after Conant sent questionnaires to 120 high schools that had been recommended to him by the Educational Testing Service, the creator of the SAT, as possible exemplars. Conant found that many of the schools were small, with between 300 and 400 students; some were even smaller. These schools already had counselor caseloads that were below 400 students. “Conant was reacting to the size of the high schools that he’s studying,” Nicola said.

Conant and his team subsequently visited 75 of these schools. On the ground, Conant noticed that counselors were often getting sidetracked into other things, like taking attendance or substitute teaching. “Just like today, they’re spending a lot of time on non-counseling tasks,” Nicola said. “He was learning that the counselors didn’t have enough time to do actual counseling, working one-on-one with students to help them progress.” That might have made Conant think that the caseload number needed to be still lower.

Conant was a renowned chemist at Harvard and a leader of the Manhattan Project so he knew a thing or two about rigorous scientific research. But Conant saw his high school report as a subjective analysis to prove that the kind of high schools he wanted to flourish in America could exist. He called it a “personal appraisal.” In the end, only eight of the high schools that he studied met with his high standards but he offered a list of 21 recommendations for all high schools across the nation.

The first of them was this:

There should be one full-time counselor (or guidance officer) for every two hundred fifty to three hundred pupils in the high school. The counselors should have had experience as teachers but should be devoting virtually full time to the counseling work; they should be familiar with the use of tests and measurements of the aptitudes and achievement of pupils. The function of the counselor is not to supplant the parents but to supplement parental advice to a youngster.

Excerpt from “The American High School Today” by James B. Conant, p. 44-45.

Conant’s report, “The American High School Today,” was published as a book in 1959. The New York Times and Washington Post featured it on their front pages and it was a widely praised bestseller.

In 1965, the American School Counselor Association codified Conant’s caseload recommendation at 250 students, the smaller end of the range, as an official policy statement.

“It gained traction because the emerging profession of school counseling was eager to lean on Conant’s prestige and authority to promote the field,” wrote Nicola.

Why the number has remained untouched for over 50 years is unclear. Modern educational researchers certainly have the data and the quantitative tools to scrutinize it. They could easily follow the same methodology that other researchers have used for studying class size, for which there is a large research literature. Instead of tracking student achievement, researchers could monitor other outcomes, such as college going rates, completion of financial aid forms and social-emotional metrics, as student caseload sizes vary.

Related: Hechinger Report stories on the guidance gap in U.S. schools

This kind of scrutiny is starting to happen right now. The counselor association itself has commissioned research to look at whether the 250 student-to-counselor ratio is optimal or if it should be a different number. Currently the association is reviewing the newest studies, such as these 2019 papers, to see if there is a new conclusion. “There’s definitely work to do,” said Jill Cook, the association’s assistant director.

In January 2020, another Harvard researcher completed a quantitative study, calculating how much extra value college counselors provide in contributing to high school graduation and college attendance rates.

And Nicola is part of a research team at Harvard’s education school, led by Mandy Savitz-Romer, that is independently looking at student-to-counselor ratios. One of the things they’re finding is that wealth and poverty matter. A 500-student-to-counselor ratio, Nicola said, can be fine in an affluent school where student needs are low. But in a low-income school, students might need a lot more counseling attention.

The counselor association “has a big push for states to adhere to the 250-to-1 ratio but that might not necessarily be what a school needs,” said Nicola. “Schools need to be able to say, we think we need a different ratio. It might be smaller than 250 and they shouldn’t feel constrained by the 250 number.”

In education, there are so many flimsy numbers that have been repeated over and over again. The 30-million word gap between high- and low-income babies wasn’t well calculated.  The giant “2 sigma” result Benjamin Bloom supposedly got from personal tutoring hasn’t been replicated. It’s possible that for over 60 years, we’ve been trying to reach a school counseling ratio that shouldn’t exist at all.

This story about the how many counselors should a school have was written by Jill Barshay and produced by The Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education. Sign up for the Hechinger newsletter.

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