Last month, the National Law Journal ranked Yale Law School 18th in job placement at large law firms — but Law School officials said they are proud of Yale’s position on the list.

The journal ranked law schools in terms of how many students they send to the largest 250 law firms in the United States immediately after graduation. For Yale, that number is about 36 percent, compared to 56 percent for top-ranked Northwestern, according to the journal’s report. Kelly Voight, the executive director of the Law School’s Career Development Office, attributed this discrepancy to divergent student interests: Many Yale students enter government and non-profit organizations after graduation, or take on clerkships and fellowships instead of entering private practice, she said.

“What this law school really values is leadership and excellence in your profession, whether you’re going to a small public interest law firm that does civil rights work or the largest law firm in New York City,” Voight said. “Our students come in with varied interests, and the survey doesn’t assess that.”

Roughly 30 percent of Yale’s class of 2009 went into clerkships immediately after graduation, and another 25 percent went into government work, non-profit organizations and fellowships, Voight said. Another 5 percent head into other fields, including business, Voight said. Overall, the class of 2009 fared about the same as past classes, which usually have around a 99 percent employment rate, she said.

For Yale students, clerkships are often considered more desirable as first jobs than posts in large law firms, Voight said. The school’s reputation for sending students to prestigious clerkships is a point of pride, Law School Dean Robert Post LAW ’77 said.

“We are proud of the school’s unique capacity to send students to excellent clerkships,” Post said.

Voight also said it can be difficult to rank schools’ success in terms of job placement because it is often difficult to define success in the legal profession.

And regardless of whether they are employed in the largest 250 firms, Post said statistics show that almost all Law School graduates are employed and satisfied with their work. And, she added, while the economic crisis has hit the law profession hard, the school is still better off than most of its peer institutions. Most second-year law students have been able to find summer associate positions that typically lead to job offers, but Voight said she has told first-year students that looking for summer positions may not be worth their time because such positions are scarce.

Before the recession, large law firms gave offers to their summer associates at a rate of anywhere from 90 to 100 percent. But last summer only half of summer associates received an offer from their firms, and many firms have stopped hiring altogether.

Ben Stern LAW ’11 said he received an offer for a summer associate position last summer, and that those who did not get hired should not despair. From what he has seen, Stern said, Law School students who only apply to a few of the top law firms are the ones unable to find jobs, while those who diversify have been more successful.

“If you were to look at a silver lining, I think it has made students more serious and engaged in the job search process than they were in the past,” Voight said.

Columbia University ranked seconnd in the Journal’s report, with Stanford and the University of Chicago in third and fourth place. Harvard Law was ranked 11th.

Correction: March 22, 2010

An earlier version of this article misstated the graduation year of Law School Dean Robert Post LAW ’77.