As young teachers at a large San Jose high school, Greg Lippman and Jennifer Andaluz could have claimed success: All the Mexican-American students in their humanities program were admitted to college.

Instead, they faced a frustrating truth: “We were taking students who were doing well coming in to high school and were going to college with us or without us,” Andaluz said. “We weren’t making a difference.”

Meanwhile, Hispanic students from poor and blue-collar families were lost in the system. Half dropped out; only 10 percent went on to a four-year college.

Successful students from low-income, Mexican immigrant families were like needles in a haystack, Andaluz and Lippman concluded. They didn’t want to spend their careers sharpening a few needles. “We wanted to educate the haystack,” says Andaluz.

So they started a charter high school, Downtown College Prep, to prepare left-behind students to succeed at four-year colleges.

To make sure they were making a difference, they recruited students with less than a C average in middle school and students who would be the first in their families to go to college, if they got that far. Some 85 percent in the first class were Mexican-American— the children of janitors, construction workers, cooks and cashiers. The average ninth grader entered with fifth-grade reading and math skills. Many had been passed along from grade to grade without doing homework or mastering the basics.

Charter schools are independently run public schools freed from some regulation in exchange for improving performance. Downtown College Prep received the same state funding as the average California school, but no money to pay for classrooms, much less for educational extras. The founders raised the extra money they needed for small classes and a longer school day from Silicon Valley philanthropists. They opened their school in 2000 in cramped classrooms rented from a church and a bankrupt fitness center six blocks away.

At first, Lippman and Andaluz thought they could boost achievement simply by setting high expectations and motivating students to work toward the goal of college. Quickly they realized students needed more than ganas:

— the desire to succeed. Most needed to learn fractions; some needed basic reading skills. Recent immigrants needed help with English.

As a charter school, Downtown College Prep had the flexibility to try ideas, look at what wasn’t working and try something else. The founders cheerfully admitted their mistakes, learned and improved.

“We’ll do whatever’s legal in the state of Californiato educate our students,” Lippman said.

Over time, students came to accept long hours, uniforms, daily homework assignments — and calls to their parents when homework wasn’t done.

They became hooked on the attention they got at the school and willing to do almost anything — even homework — to remain in the school community.

Each year, the new students come from more disadvantaged families, measured by parents’ income and education. Yet the school’s score on the state’s Academic Performance Index now surpasses the California average.

All graduates have gone on to four-year colleges.

Downtown College Prep is making a difference. And it’s not alone. Education Trust, a Washington-based nonprofit, compared high-minority, high-poverty high schools that have a “high impact” on student achievement with “average-impact” schools that don’t make much of a difference for low-performing students.

High-impact schools give extra help, such as mandatory summer school or after-school tutoring, to students before they fail. Average-impact schools wait.

Downtown College Prep requires all incoming ninth graders attend a summer school orientation and requires a daily 70-minute study period for all students in ninth through 11th grade. (I was a volunteer tutor.)

High-impact schools assign teachers based on their specialties and students’ needs; in average-impact schools, seniority and teacher preferences determine who teaches what. Often the most experienced teachers choose to teach the easiest students while the neediest students make do with inexperienced teachers.

Downtown College Prep doesn’t have a lot of easy students; it’s staffed by non-union teachers who’ve chosen to teach there because they share the school’s values and believe in the mission.

At most schools, students who are behind get extra time to learn English and math. But the high-impact schools make sure students also meet college-prep requirements while average-impact schools put students on a remedial track that keeps them out of college-prep courses.

Downtown College Prep’s ninth graders who take remedial English and remedial math also take the college-prep English 1 and Algebra 1 course, even if it’s very likely they’ll fail the first time. They can try again in summer school. If necessary, they can repeat ninth grade.

It’s not easy for a high school to make a difference in students’ lives when they arrive with a long history of failure and frustration. It’s not easy. But it can be done.

Education blogger Joanne Jacobs, a former Knight Ridder columnist, is the author of Our School: The Inspiring Story of Two Teachers, One Big Idea and the School That Beat the Odds (Palgrave Macmillan, Dec. 1, 2005), a book that charts the progress and success of Downtown College Prep.