Equations not quite erased on the blackboard in a classroom at Northern Virginia Community College. (Bill O'Leary/The Washington Post)

Sonja Anderson represented a vital part of Northern Virginia Community College’s huge enrollment. She was an electronic-applications engineer who had learned on the job and needed a bachelor’s degree to be paid what she was worth. She was old enough to have a daughter at the college at the same time she was there.

They took the same course one year, a cute story to tell friends and family. But Anderson frequently was frustrated and disappointed with the nation’s second-largest community college. The website for NOVA, as it is called, said it “can take you anywhere you want to go.” Anderson discovered the school, like many community colleges, often fell short.

“I persevered through stubbornness, but I saw so many students tolerate incompetent, inadequate, imperious and bureaucratic road blocks as a matter of course,” Anderson said.

Educators praise President Obama’s call for free tuition in community colleges, repeated during the State of the Union speech last week, but that focus on cost distracts from more serious problems.

A new, detailed analysis by Columbia University scholars exposes the dearth of competent community college advisers. Anderson saw that firsthand.

“The advising staff was ignorant of key graduation requirements,” she said. “I had no adviser for my first two years. There was a blank where my adviser’s name was supposed to be.

“I eventually asked someone at the Annandale campus if they would provide advising, and they did. He was a math professor, but at least I had someone to advocate for me.

“Professors don’t have to be good teachers,” she said. “Students need to use RateMyProfessors.com and similar websites in order to avoid wasting money and time and to ensure they will learn what they need. When I found a great teacher, I took every class that I could find from him or her.

“In my history class, we were told that if we used any information from the assigned textbook, we would receive an F,” she said. “The professor wrote her own version of history, and that was what we had to learn.”

She added: “I once withdrew from a calculus class after the first exam did not match the lessons and homework in the textbook. The professor was brand new, adjunct, in the process of completing his PhD and found the assigned curriculum uninteresting.”

The next semester she took the same course from a full-time professor, and the lectures were 90 percent different, Anderson said. She worried about classmates in the previous class who could not afford to wait one more semester.

“I took a computer science course where I did not receive any grades for the first half of the semester, until I complained to the department head,” she recalled. “The professor gave us exams with questions about things we had never heard of. It turned out to be material that had been deleted from the textbook years earlier, but the professor just downloaded an exam and didn’t read it.”

NOVA spokeswoman Kathy Thompson told me that the school’s Quality Enhancement Plan is working “to retain students by establishing relationships, fostering connections with advisers and faculty, and teaching students how to plan and evaluate their academic performance.” As for Anderson’s complaints about faculty, Thompson said, “Faculty members are afforded the academic freedom to teach to their particular style and personality,” but there are processes to address student grievances.

Anderson earned associate degrees magna cum laude in electrical engineering and math in late 2014. At 51, she is about to begin her last semester at George Mason University to get her bachelor of science degree.

If every community college student were as dogged and savvy as she was, perhaps the system would work in spite of itself. But that cannot be expected of young people who are often in community college because they have struggled in high school and need clear advice and good teaching to succeed.

The 42 percent of American undergraduates who attend community college deserve better than they are getting.