A shortage of substitute teachers nationwide has school districts scrambling to fill positions, with some raising pay as they try to attract more applicants as the economy improves.

School officials say the problem has forced schools to divide classes when teachers are absent, making it more difficult for teachers to be effective. Using other school staff also causes problems, detracting from other duties.

A frequent source of substitutes has been education majors looking for experience. But officials say fewer college students are choosing teaching as a career path.

The founder of the Substitute Teaching Institute at Utah State, which in 2008 spun off into an online training program for substitutes, says increased pay alone usually doesn't attract more qualified substitutes. Geoffrey Smith says they also want better training.