Professional development courses help teachers improve their skills and, ideally, rise among the ranks.

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Teachers are lifelong learners. In fact, ongoing education is a requirement for teachers of every public school level, from kindergarten through 12th grade. Known as professional development, this education -- usually in the form of workshops, seminars and training courses -- helps teachers stay up to date with new trends and learn fresh strategies, techniques and methods for classroom challenges. The overriding idea behind professional development is that increased knowledge helps teachers improve student achievement. That's because professional development focuses on what each teacher needs to fine-tune his or her classroom practice.

But before any professional development can take place, a teacher must first become certified. In all 50 U.S. states, the standards for becoming a public school teacher -- either as a generalist teaching a grade level or as a specialist teaching a specific subject -- are similar: Earn a bachelor's degree, take a state-mandated teaching examination and fulfill a few other requirements, such as specific education courses or student teaching experience. Additionally, a teacher can earn national certification that's accepted in all states [source: All Education Schools].

Once a teacher is in the classroom, his or her teaching license will come up for renewal every few years. To recertify, professional development is required. For example, in Kansas -- as in most states -- new teachers operate under an initial license. After five years of teaching and completing professional development, one can earn a "professional" license; and at the 10-year mark, one can earn an "accomplished" license for finishing a professional development plan and passing a test [source: KSDE]. Many states also require teachers to complete a certain number of professional development hours each year [source: ADE].

But there are plenty of reasons -- beyond license renewal -- for teachers to continue their education. Sometimes there are financial incentives, such as salary increases. But often, the rewards aren't found just at the completion of professional development, but all along the way. According to U.S. Secretary of Education Arne Duncan, professional development transforms the nation's best teachers. "It's a lot of hard work but arguably the most important growth and learning you're ever going to have as a teacher," he said [source: NBPTS]. There's little doubt professional development can be a boon, but why don't all teachers have one universal route for continuing their educations? We'll explain on the next page.