Tenure would require demonstrated knowledge and skill, as at a university or a law firm. A rigorous board exam for teachers could significantly elevate the quality of candidates, raise and make more consistent teacher skill level, improve student outcomes, and strengthen the public’s regard for teachers and teaching.

We let doctors operate, pilots fly, and engineers build because their fields have developed effective ways of certifying that they can do these things. Teaching, on the whole, lacks this specialized knowledge base; teachers teach based mostly on what they have picked up from experience and from their colleagues.

Anthony S. Bryk, president of the Carnegie Foundation for the Advancement of Teaching, has estimated that other fields spend 5 percent to 15 percent of their budgets on research and development, while in education, it is around 0.25 percent. Education-school researchers publish for fellow academics; teachers develop practical knowledge but do not evaluate or share it; commercial curriculum designers make what districts and states will buy, with little regard for quality. We most likely will need the creation of new institutions — an educational equivalent of the National Institutes of Health, the main funder of biomedical research in America — if we are to make serious headway.

We also need to develop a career arc for teaching and a differentiated salary structure to match it. Like medical residents in teaching hospitals, rookie teachers should be carefully overseen by experts as they move from apprenticeship to proficiency, and then mastery. Early- to mid-career teachers need time to collaborate and explore new directions — having mastered the basics, this is the stage when they can refine their skills. The system should reward master teachers with salaries commensurate with leading professionals in other fields.

In the past few years, 45 states and the District of Columbia have adopted Common Core standards that ask much more of students; raising standards for teachers is a critical parallel step. We have an almost endless list of things that we would like the next generation of schools to do: teach critical thinking, foster collaboration, incorporate technology, become more student-centered and engaging. The more skilled our teachers, the greater our chances of achieving these goals.

Undergraduate education programs and graduate schools of education have long been faulted for being too disconnected from the realities of practice. The past 25 years have seen the creation of an array of different providers to train teachers — programs like Teach for America, urban-teacher residencies and, most recently, schools like High Tech High in San Diego and Match High School in Boston that are running their own teacher-training programs.

Again, research suggests that the labels don’t matter — there are good and bad programs of all types, including university-based ones. The best programs draw people who majored as undergraduates in the subjects they wanted to teach; focus on extensive clinical practice rather than on classroom theory; are selective in choosing their applicants rather than treating students as a revenue stream; and use data about how their students fare as teachers to assess and revise their practice.

THE changes needed to professionalize American education won’t be easy. They will require money, political will and the audacity to imagine that teaching could be a profession on a par with fields like law and medicine. But failure to change will be more costly — we could look up in another 30 years and find ourselves, once again, no better off than we are today. Several of today’s top performers, like South Korea, Finland and Singapore, moved to the top of the charts in one generation. Real change in America is possible, but only if we stop tinkering at the margins.