Emily Gersema Tiny levers, cranks, joints and axles are dumped onto the table as sophomores at Paradise Valley's Horizon High School study how to piece together a miniature conveyor belt and universal joint. As sophomore Jerry Trayer fiddled with the pieces and fit together the elbowlike joint, he explained why he is taking this pre- engineering course. "I really wanted actual college credit," said Trayer, of Scottsdale. Now he and other students in this special engineering preparation program can get it. Horizon High School became the fifth Arizona school this month to obtain what is called "affiliate" certification by Project Lead the Way so students in its engineering-preparation program can earn college credit. Other schools with a for-college credit PLTW program are: Gilbert's Desert Ridge High School, Mesa's Fremont and Shepherd junior highs, and Red Mountain High School. Rigorous process The five schools have gone through a rigorous application and review process and were visited by a PLTW accreditation team, said Joseph Tidwell, an Arizona State University Polytechnic professor who directs the Joint Alliance of Companies Managing Education for Technology. The affiliate certificate is significant. Arizona treats PLTW as a career and technical education option. This means students earn elective credit hours, not science or math credit, even though they are learning advanced math and science concepts like many of those taught in Advanced Placement, or honors, courses. Without an affiliate certificate, a school cannot give its PLTW students an opportunity to test for and earn college credit. Without college credit, some students may lose interest or not enroll in the courses. PLTW has been touted by tech companies and federal education officials as a model program for schools nationwide because it teaches high-school students skills they will need to perform well in college-level math and science courses and in a full-time job in science, technology, engineering or math -- STEM. Created by industry representatives and educators in 1998, the not-for-profit company PLTW has four-year preparation programs now in more than 3,400 schools nationwide. One program, which Horizon High School offers, prepares students for college and technical jobs by teaching basic physics, math and engineering concepts. The second program teaches students concepts of biomedicine and biotechnology that prepare them for studies and careers in the health-care field, law enforcement, forensics, drug research and other such areas. Twenty-three schools across Arizona have earned certificates to run a PLTW program. Most have the pre-engineering program. The biomedical program is available at Gilbert's Campo Verde High School and Douglas High School, which also has the engineering program. Teacher training Schools obtain a certificate to run a PLTW program, and recertify every five years. Program teachers go through 80 hours of training. "Teachers are in there from 9 a.m. to 1 or 2 a.m. every day. They do a full year's worth of curriculum in two weeks," Tidwell said. Shawn Hardina, who teaches the PLTW biomedical program at Campo Verde High School, said the coursework is designed to be very hands-on and drives students to work harder to solve problems. "We've talked about the difference between getting an 'A' and learning," Hardina said. "I think they're smarter and more talented and have more ability than they think they have. I've told them: Sometimes you don't know it's right, but you have to just go with it." Valley Project Lead The Way Biomedical * Campo Verde High School, Gilbert Public Schools. Engineering * Basha High School, Chandler Unified School District. * Chaparral Elementary School, Higley Unified School District. * Cortina Elementary School, Higley Unified School District. * Desert Ridge High School, Gilbert Public Schools. * Fremont Junior High, Mesa Public Schools. * Higley High School, Higley Unified School District. * Horizon High School, Paradise Valley Unified School District. * Mountain View High School, Mesa Public Schools. * North Canyon High School, Paradise Valley Unified School District. * Paradise Valley High School, Paradise Valley Unified. * Payne Junior High, Chandler Unified School District. * Red Mountain High, Mesa Public Schools. * Shadow Mountain High, Paradise Valley Unified School District. * Shepherd Junior High, Mesa Public Schools. * Verrado High School, Agua Fria Union School District.