BERKELEY, Calif. — School day wake-up calls recorded by celebrities. Weekend makeup classes. Contests with laptop computers, private concerts and cars as prizes.

Educators across the nation are using creative strategies as another school year gets under way to convince students and parents that regular attendance matters — and not just for grades and achievement.

New research suggests missing as little as two weeks of school can put young children behind their peers, burden overworked teachers, cost districts state dollars and undermine mandates to raise standardized test scores. So many public school districts have launched campaigns to reduce all absences, not just those serious enough to warrant a home visit from a truant officer.

The attendance push has been particularly strong in California, New York, Texas and other states where schools funding is based on how many children are in their seats each day, rather than enrollment. Several California districts have made a back-to-school ritual of reminding parents that schools lose money whenever kids are out.

Some have asked families with children who missed school for avoidable reasons such as family trips to reimburse schools the $30-$50 a day the absence cost in lost funding, or at least consider having a child with the sniffles or a stomach ache show up for the first part of the day so he or she can be counted before going home sick.

Ken Seeley, president of the National Center for School Engagement in Denver, said when it comes to devising strategies for getting kids to school, the approaches do not need to be flashy. “We give away a lot of alarm clocks.”