With their final exams behind them, hundreds of students in the Liberty Union High School District now are waiting to find out whether their scores will earn them college credit.

And the chances that they will are better, because over the past decade those taking Advanced Placement tests have been getting higher marks.

This past year the district offered 18 college-level courses known as Advanced Placement, and the end-of-year exams that students in them took can give them a head start on their academic future if they score at least a 3 on a scale of 1 to 5.

The AP curriculum emphasizes reasoning over regurgitating formulaic answers.

"It's challenging intellectually," said Joe Radding, administrator of college preparation programs for the California Department of Education. "The material doesn't simply ask for rote responses or memorization. It encourages the development of critical thinking skills, problem-solving skills."

AP classes also take up considerably more time: Francisco Borja, a Heritage High School 16-year-old who signed up for five of them this past school year in addition to three non-AP courses, had around five hours of homework nightly and during the week routinely studied until midnight or 1 a.m.

Slight increases in numbers taking tests

The percentage of Liberty Union High School District students signing up for these extra-challenging classes is small and has increased

Not quite 19 percent of students at the mainstream high schools took one or more AP exams in 2000-01; despite the growth in enrollment since then, the 677 who sat for the tests last year comprised only 21 percent of all students on the Liberty, Heritage and Freedom campuses.

Liberty High School AP teacher Paul Taylor thinks part of the reason is the school district's noticeable demographic shift over the past decade: Data shows that more students at its feeder schools are from lower-income families and their parents less educated, he said.

And if parents don't have college experiences to share with their children, those young people might be surprised by the level of difficulty they encounter in an AP class, Taylor said.

Kids not only need solid writing, reading and analytical skills at the outset, he said, but they must be mature enough to manage their time well so they stay on top of assignments.

"If you go in deficient it's going to be a brutal experience," Taylor said.

Some teens avoid AP classes because they don't want to expend the effort, others because they're afraid they can't handle the work, he said.

Jim Key, who teaches AP psychology at Liberty High, agrees that the fear factor might play a part.

"Perhaps some of them are scared out of it," he said, noting that he and his colleagues try to present a realistic view of what the classes entail.

District Assistant Superintendent of Educational Services Mary Vinciguerra thinks the $87 fee to take each test might dissuade others whose parents earn too much for them to qualify for a discount but not enough to absorb the cost easily.

Liberty High School Principal Pat Walsh wants to see more kids taking AP courses, and is asking his teachers to keep an eye out for students they think would do well in them.

In addition, some instructors and guidance counselors are starting to check a password-protected website for the names of high schoolers the College Board identifies as "AP potential" so they can encourage those students to enroll, Walsh said.

Kids faring better on tests

The more significant change to Liberty Union High School District's AP statistics is how teens are faring on the tests: Over the span of a decade the rate of success has risen from 40 percent to 61 percent.

By contrast, the number of tests receiving qualifying scores in Antioch Unified School District increased from 40 percent to 46 percent over the same period. In Pittsburg Unified School District, the figure rose from 43 percent to 49 percent.

Liberty High statistics teacher Jenny Weinert thinks that the specialized training she and her colleagues receive to teach AP courses might account for the improving pass rates.

They attend annual conferences where they learn test-taking strategies and about activities students can do in class as well as how to teach the higher-level thinking that AP tests demand, Weinert said.

For example, whereas students in ordinary math classes tend to take a rote approach to solving problems, AP students must figure out which of multiple methods to apply to a calculation, she said.

Another reason for the increased number of tests with qualifying scores might simply be that AP instructors usually teach the same course year after year and thus become proficient at conveying the curriculum, Weinert said.

Whatever the reason, Huong Tran is hoping the results she gets will enable her to skip some classes in college.

The Heritage High School junior just finished no fewer than five AP courses and intends to register for four more as a senior.

Taking multiple tests is a pricey gamble, but Tran reasons that if she can get her college degree faster she'll save her parents money in the long run.

Apart from the chance to test her intellectual mettle, taking classes that colleges might accept as substitutes for what they offer is also why 16-year-old Anneka Weinert already has completed eight AP classes and plans to take five more.

More AP advantages

Success on AP exams offers other advantages as well.

Incoming freshmen who have advanced standing still can graduate in four years without having to take a full load each semester; some might opt to spend that extra free time doing an internship, Walsh said.

"It gives the student additional possibilities," he said.

Tran, 17, hopes that all the AP classes she's taking also will give her an edge when she applies to the University of California at Davis -- her first choice -- where 45.6 percent of freshman applicants were accepted for 2012-13.

Having AP courses and test scores that qualify for college credit on a transcript is a plus because it means the student is that much more prepared, said Anne De Luca, associate vice chancellor for admissions and enrollment at UC Berkeley, although she emphasized that it's still just one of multiple factors that admissions officers consider.

"I just want colleges to look at my application and think I'm not the normal high schooler," said Tran, who's set her sights on becoming a pediatrician. "I want them to think that I'm unique."

Contact Rowena Coetsee at 925-779-7141.