IF AMERICANS harbored any doubts about their eroded global edge, the recent release of the Organization of Economic Cooperation and Development’s fourth international comparison of educational performance should rattle the nation from its “We’re No. 1’’ complacency. The latest Program for International Student Assessment study revealed that, although the United States made some modest gains, it is lagging behind many other developed nations in the ability of its 15-year-olds. The country isn’t flunking: like France, England, and Sweden, learning here has stagnated at below-average levels. That “gentleman’s C’’ should be a call to change course.

Take heart. Finland, one of the world’s top educational performers according to the last PISA study and a recent McKinsey report, was once in a similar slump and can offer lessons for the United States and others seeking a cure for poor public schools.

As recently as 25 years ago, Finnish students were below the international average in mathematics and science. There also were large learning differences between schools, with urban or affluent students typically outperforming their rural or low-income peers. Today, as the most recent PISA study proves, Finland is one of the few nations that have accomplished both a high quality of learning and equity in learning at the same time. The best school systems are the most equitable — students do well regardless of their socio-economic background. Finally, Finland should interest US educators because Finns have employed very distinct ideas and policies in reforming education, many the exact opposite of what’s being tried in the United States.

Finland has a different approach to student testing and how test data can or should not be used. Finnish children never take a standardized test. Nor are there standardized tests used to compare teachers or schools to each other. Teachers, students, and parents are all involved in assessing and also deciding how well schools, teachers, or students do what they are supposed to do. Politicians and administrators are informed about how well the education system works by using sample-based learning tests which place no pressure on schools, and by research targeted to understand better how schools work. Parents and politicians think that teachers who work closely together with parents are the best judges of how well their children are learning in schools.