In recent decades, teachers wanting to break away from traditional classroom methodologies have altered their teaching approach to conform to the "learning styles" of their students. The idea is that students learn better when they are taught in a way that corresponds with their preferred style. For example, "visual learners" can comprehend information more easily when they are presented with diagrams or illustrations, whereas other students may learn more easily through listening, or by working their hands.

The practice of categorizing students by learning style has caught on: 96 percent of teachers surveyed recently said they believed in the idea. It is not difficult to see why such a system would be attractive to teachers seeking to better meet their students' needs. The theory has also been embraced by parents whose children are struggling in school -- the idea that their child may perform poorly on written tests because they are actually "picture smart" or "music smart" is appealing. As the learning-styles theory has grown in popularity, dozens of supposed styles have been identified, and an entire industry has grown up around the idea, with conferences being held across the world and libraries offering materials intended to help educators teach different types of learners.

One would think that a method with such a significant influence on classroom approaches would have extensive research behind it. However, there is little solid proof that teaching to a student's strengths is an effective practice. In fact, researchers have found major flaws in methods used to quantify learning styles. The idea is based on the classification of people into specific types of learners , but studies have found very little evidence that people actually fall into distinct groupings in this way. "I think as a purely reflective exercise, just to get you thinking about your study habits, [learning styles might have a benefit," says Polly Husmann, an assistant professor at Indiana University School of Medicine. "But the way we've been categorizing these learning styles doesn't see to hold up."

While students often express and demonstrate preferences for specific methods, studies show that what actually helps them learn better is for the educator to ensure the teaching approach suits the material being taught. University of Virginia professor Daniel Willingham says, "People's alleged learning styles don't count anything in accounting for task performance, but the effect of a strategy on a task is huge." Learning a new language, for example, is easier when the material is reviewed verbally, but math concepts such as geometry are better suited to visual methods. In addition, all students can benefit from lessons that combine different approaches to make material easier to understand. For example, a math teacher can encourage students to listen, read and draw diagrams to solve problems. The current focus on matching teaching methods to specific types of learners has taken such a hold, however, that Willingham believes the only way to counter it is to revise the textbooks on educational theory. Only when the theory of learning styles is no longer presented as a valid educational approach will it disappear from the classroom.