When I was in junior high, just after a grade skip, I was mostly in "tracked" classes. Although I didn't like the grade skip (from fifth to seventh, which put me in a new school while my previous classmates were still in sixth grade at the elementary school), I did like being among classmates who in general were smarter than average. (I still had industrial arts classes and physical education classes with the general school population, and there was only one choir class.)

I hear that now that junior high schools are mostly called "middle schools," there has been a strong middle school philosophy of having all classes for early adolescents be heterogeneously grouped. That doesn't sound like a good educational idea to me. I fully approve of the idea of young people learning to get along with people of all ability levels. I have good friends from my non-tracked elementary school classes whom I am catching up with recently after FORTY YEARS of not seeing one another. (Facebook has helped a lot with that reconnecting.) I have lifelong friends from the tracked classes after the grade skip too, including a childhood best friend after whom I named my oldest son.

Even more important than grouping by ability, methinks, is upping the curriculum standard for everybody. In Taiwan, where my wife grew up, the seventh grade mathematics curriculum includes a good bit of algebra and geometry for everybody--including all the below-average students. I didn't see algebra, even with a tracked math class, until eighth grade in Minnesota, and when my family moved to Wisconsin the next school year, the highest math class in ninth grade was studying the same beginning algebra class from the same textbook I had already had the year before. The countries with the best performance in primary schooling get it in large part by having specialist teachers in the core subjects in elementary school. United States elementary teachers are expected to be generalists, but in practice they devote a lot of time and effort being jacks of all trades but masters of none.

http://www.ams.org/notices/200502/fea-kenschaft.pdf

Let's do better for everybody in school. Let's get a reality check on aspirations by emulating best practice wherever it is found.

One statement in the article especially stood out to me: "Exercises in grammar have declined to the point that they are virtually extinct." I have observed this in suburban schools in the area near where I live. My second son (an aspiring writer since early homeschooling days, who has pursued a lot of knowledge about writing) reports that few of his classmates in the high school classes he now attends have had any instruction in grammar. I have been doing some tutoring for college entrance tests from time to time, and really, really bright young people who need no help at all from me in mathematics have not learned even the most basic grammatical terminology for revising English prose or identifying errors in writing. Ouch.

AFTER EDIT: I see another comment in this thread includes the statement

but by 18 or so the majority of the population will have arrived at a similar skill level in most subjects[1].

That is not factually correct.

http://www.usnews.com/education/blogs/high-school-notes/2012...

And the reference provided for the statement, about "regression to the mean," illustrates that the statement is untrue, because when I graduated from high school, I was aware that that claimed situation is NOT what "regression to the mean" is about. Most eighteen-year-olds, and plenty of older people, have no idea what regression to the mean is. There is a huge variation in skill level in most subjects among eighteen-year-olds in the United States and most places.