The education world is abuzz with the release Wednesday of draft curriculum guidelines by the Common Core State Standards Initiative. CCSSI’s draft is closely watched because the Obama administration plans to withhold billions in federal funding from states that refuse to adopt it, or something very similar.

The whole idea of imposing a single set of age-based standards on all students rests on a false premise: that children are identical widgets capable of being dragged along an instructional conveyor belt at the same pace, benefiting equally from the experience.

But kids are different — not only from one another, but when it comes to their own varying facility across subjects as well. Any single set of age-based standards, no matter how thoughtfully conceived, will necessarily be too slow or too fast for most children.

Consider a concrete example. The new CCSSI math standards place trigonometric functions (sine, cosine, etc.) well into the high school curriculum. Students would be taught this material in their mid teens. What good would that do for someone like Dick, who wrote this:

[W]hen I was eleven or twelve, I had read a book on trigonometry that I had checked out from the library.… A few years later, when we studied trigonometry in school, I still had my notes and I saw that my [theorem proofs] were often different from those in the book. Sometimes, for a thing where I didn’t notice a simple way to do it, I went all over the place till I got it. Other times, my way was most clever — the standard demonstration in the book was much more complicated! So sometimes I had ‘em beat, and sometimes it was the other way around.

Dick — Richard P. Feynmann — told many other entertaining stories in his book Surely You’re Joking, Mr. Feynmann… like the time he asked a Time magazine reporter if he could refuse the Nobel Prize in Physics (“no”).

How does teaching (or re-teaching) trigonometry to all children at the same age help math whizzes like Feynmann? How does it help kids who find mathematics rough going, and lag behind their peers no matter how much support they receive from parents and teachers? The answer is obvious: it doesn’t.

There is a far better alternative: group students based on their level of mastery in each subject, instead of strictly by age, so that each can progress as fast as he or she is able. By doing so, all children are taught the things they are ready to learn at any given time. No one need be bored into a stupor nor left hopelessly behind.

Not only is this approach feasible in theory, it is already in widespread use with millions of students worldwide, in the for-profit tutoring sector. When a child comes to a Sylvan Learning or Kumon center facing difficulty with trigonometry, he is not taught basic arithmetic or advanced calculus. He is taught the specific material in which his deficit lies. He moves on to more advanced material as soon as he has mastered the prerequisite skills, and not before.

Neither is this a cutting edge pedagogical innovation. The Jesuits adopted the practice in their own education standards document, the Ratio Studiorum, in 1599:

There is to be a general and formal promotion once a year after the annual vacation. If, however, any show superior ability and give promise of making better progress in a higher class than their own…, they should not be kept back but may be promoted any time during the year, after an examination.… No one is to be advanced from the first to the second year, nor from the second to the third, unless he has shown moderate ability in understanding the subject matter of the lectures and is able to demonstrate this understanding by proofs.

Despite its long history and obvious merits, performance-based grouping is not on the administration’s radar and is not coming to a public school system near you. The children-as-interchangeable-widgets paradigm is the order of the day.

So why is performance-based grouping ubiquitous in for-profit tutoring centers? Because parents won’t pay to have little Johnny taught algebra when he hasn’t yet mastered arithmetic, or to have Jane taught nursery rhymes long after she’s been curling up with J. K. Rowling. Tutoring centers must adopt the most practical and effective policies, or lose clients to competitors who do.

Public schools face no such pressures, and so we have the dominance of age-based grading — and now the push for homogenizing national standards. These may make life simpler for schools. They do not serve the educational needs of children.