In a growing trend both in the state of Washington and in some Inland Northwest school districts, more students than ever are taking Advanced Placement subject exams.

Local educators attribute the trend to a greater emphasis by schools to prepare students for postsecondary education by offering more rigorous courses, as well as to rising student interest in obtaining college credit while still in high school.

Advanced Placement (AP) exams are part multiple choice and part essay tests on specific subjects. The tests measure a student's ability to perform at a college level and are graded on a scale of one to five, with five being the highest possible score. Scores of three and above are considered passing marks.

At many colleges and universities, a passing grade on an AP exam earns a student partial or full credit for an introductory college course on the subject for which the exam was taken. The amount of credit a student receives can vary at each institution, and also depends on what score he or she received. How much credit is awarded also may depend on the subject of the exam.

Many high schools here offer AP courses specifically designed to prepare students to take the tests.

In the Spokane area's largest school district, Spokane Public Schools, the number of students taking an AP exam has increased by 65 percent in the last five years, to just over 1,200 high school students in 2010 from 730 in 2006, district data show.

Karin Short, Spokane Public Schools' associate superintendent for teaching and learning, says the district has been offering its students the option to take an AP prep course since 1999, when it offered around a dozen districtwide. Now, the district gives students the option to take almost two dozen AP courses, including in English, U.S. government, world history, calculus, biology, and statistics, among others.

When the district first began teaching AP courses, she says, fewer students were able to enroll in the classes because there weren't many sections of each class available. Now, because the district has not only expanded its overall AP course offerings but also the number of class sections in each subject, more students are able to take the prep courses and thus are more likely to sign up to take the exam at the end of the year.

"We want to increase the number of kids who take AP courses and offer equal opportunity to them," Short says. "There are many other courses now, so our enrollment is dramatically increasing."

Spokane Public Schools' average test score in 2010 was 2.69, which is below the state's average of 2.92 and is slightly lower than the average scores the district saw between 1999 and 2006. During that time, the number of students passing ranged between 75 percent and 80 percent, but that rate since has dropped to 55 percent in 2010.

"Proportionally, we don't have 80 to 90 percent of students getting a three or above because we have so many more participating," Short says.

Last year, more than 35,600 students in Washington took at least one AP exam, with a total of about 58,900 exams taken. The number of students in the state taking an AP test increased by about 7 percent from 2009 to 2010, and by more than 37 percent over the last five years, according to data from the College Board, the national college-readiness nonprofit that writes and grades the AP exams, as well as the SAT test.

Students in the Central Valley School District, in Spokane Valley, also are mirroring Washington state's AP test trends. The number of tests taken by students in the district has increased by about 6 percent from 2008 to 2010, data show. Last year, 346 students at the district's two high schools took a total of 675 exams.

Sherry Clark, assistant principal of curriculum and assessment for University High School in Spokane Valley, says that University High School this year offered its students AP courses on 11 different subjects, and it plans to continue expanding that number.

"We've made a concerted effort at U-High over the last five to seven years to increase our AP enrollment and still keep our scores high," Clark says. "We've added to the number of classes we offer and the number of sections; and we have an increase this year over the 2009-2010 year of 40 percent more students taking any one AP test."

Pam Stickney, the AP coordinator and counselor at Central Valley, says that high school has seen similar demand from its students.

"It's increasing every year," Stickney says, adding that the school so far plans to administer a total of 584 AP exams next month. She says that this year more than 300 students at Central Valley will take at least one AP exam, but that many students there also plan to take multiple exams, a trend that's also growing each year.

"We have some students that will have taken 10 AP exams by the time they graduate," Stickney says. Some of those high-achieving students will be the school's valedictorians and salutatorians, she adds.

Soon, all public high schools in Washington state will be offering more AP exams. House Bill 1808, a bill Gov. Christine Gregoire signed into law April 15, will establish requirements of public high schools to offer a sufficient number of college-level courses to give students the opportunity to earn a year's worth of college credit while in high school for passing AP exams.

That measure also requires institutions of higher learning to develop master lists of courses that could be fulfilled by achieving a certain score on an AP test or other proficiency exam. It will also require those lists to be published by the Higher Education Coordinating Board, which will distribute the lists to schools.

In an effort similar to what Spokane Public Schools and the Central Valley School District are doing, the Coeur d'Alene School District in North Idaho is expanding opportunities for its students to take an AP course.

As a state, Idaho had about 4,800 students who took at least one AP exam in 2010.

Michael Nelson, the district's director of assessments, says the district just began offering AP courses at Coeur d'Alene High School during its last school year.

Prior to the 2009-2010 school year, however, many students took AP tests on their own without the aid of a preparatory course, he says.

"We're pleased with the results this last year," he says. "We'd like to see a more cohesive program, since before that only a small number of students were taking the tests of their own choice."

Last year, Coeur d'Alene School District students took 274 AP exams, data show.

While Coeur d'Alene High School now offers a total of 10 AP courses, students attending Lake City High School have the opportunity to take what are called International Baccalaureate (IB) courses and exams.

Nelson says the IB program is similar to AP in the level of difficulty of the course and exam material, but the main difference is that IB is an international testing standard, whereas the AP exams apply a national standard.

Nelson says the district offers the different programs at its two high schools to give students the option of which advanced courses to take.

He says that the district plans to continue increasing the number of AP and IB classes its students can take at both schools.

Each AP test costs $87 to take, and Washington state offers some assistance to low-income students who might have difficulty paying that amount.

Barbara Dittrich, the program supervisor for Advanced Placement at the state's Office of the Superintendent of Public Instruction, says that students enrolled in the National School Lunch Program, which offers free or reduced lunches to low-income students, can receive assistance in paying for the cost of an AP test. Those students only pay $5 of the test fee, Dittrich says.