This is not exactly what you are looking for, Val, but this post on Willingham's blog discusses a recent meta-analysis of studies on the effects of retention. I'm linking the blog post rather than the articles because I often find Willingham's posts interesting and because I have read the post but not the articles. The first article is freely accessible, haven't checked the second.

More generally, I'd be wary of confirmation bias if I were you, Beckee. That is, to what extent are you and the other teachers seeing an effect that you expect to see because you expect to see it? That happens to everyone and we all just have to guard against it.

Also, if the pedagogical approach is dependent on some kids "getting" the lesson, and no such kids are in the classroom, then maybe the lesson itself needs to change? At least, that's one thing that occurs to me. I am aware that teachers do not necessarily have control over how material is taught and that some groups of people just seem flat.

I don't mind if my kids are role models and explaining things to classmates some of the time, but if they are always in that position then they may be in the wrong classroom.

I liked Willingham's book "Why Don't Students Like School: A Cognitive Scientist Answers Questions About How the Mind Works and What It Means for the Classroom".

And it shortchanges us all.

Asking less than capable kids to go to college rather than votech and holding bright kids back so that they become underachievers benefits whom? No one. We waste public money and lives for what?

Again, it benefits no one and shortchanges us all.

I haven't read all the responses to the OP. I'm responding only to the OP's question - how is ability grouping going in public schools that are doing it. We are in a public elementary school in one of the cities listed by the OP. Our school has been ability grouping for reading and math for about six years now, and it's going extremely well, evidenced by test score increases, and student/parent satisfaction. It's one of the main reasons we chose our school (which also happens to be our neighborhood school), and we have long waitlists of students trying to choice in from adjacent elementary school districts.

They take a class of 90 kids and shuffle them among the three grade level teachers, plus ESL and intervention teachers if needed, for reading, and do the same for math, minus the ESL/intervention teachers. They reshuffle the kids throughout the year if they need to based on scores/performance, although our DS's classes have stayed fairly static. The reading classes are further broken into three to five ability groupings within the overall reading class. So my DS, for example, is in the lowest ability reading group in the highest ability reading class.

The high ability 1st grade math class is actually doing higher level math right now than the lowest ability 2nd grade math class. The 2nd grade high ability reading class has readers spanning about 5th to 10th grade level.

The school also still moves very high ability kids to other grades by subject, but typically only if the parents push for it or you happen to get one of the teachers who's really on top of it. I see the effects when I volunteer in the ability-grouped reading class versus the homeroom class - the ability-grouped class is more focused because they don't have as many outliers who are either bored or over-challenged. The ability grouping plus subject acceleration for math is working very well for our DS, and I know a number of parents who have chosen to keep their children at our school rather than move them into the HGT magnet program in our neighborhood.

Our old VP moved to another neighborhood school and started implementing the model there last year. Friends at that school also seem happy with the model. I don't know what other schools in our city are following the model.

When you ask a question, and a student raises their hand and answers the question instead of telling you they need a pencil, or saying something inappropriate, that student is not being exploited for social engineering purposes. Yet, they have a positive effect on other students around them when that happens, in many ways.

Parents make the best decisions they can with the children and resources they've got. So do teachers. But when the good students leave, we miss them. And when the gifted students get to be as surly and lazy as I was when I was in 6th grade, we wish we had a better learning experience for them.

And that's all I have to say about that.

Our kids have been in classes that were both heterogeneous and ability grouped in elementary school.

One of DD13's best memories is her third grade year, where her entire class was gifted. The teacher had a squadron of helpful, connected parents (she had FOUR room moms!), a class that was engaged and excited and stimulated by the pace set by their peers, and CRCT scores that were the highest in the history of the school (which was considered a top ten in the state already).

It was a magical year, and the teacher was in tears the last day because the school chose not to continue with it next year because of sniping from other parents.

The flip side? In the heterogeneous classes DD11 would finish her work in five minutes, then spend the rest of the time teaching her friends the material and helping them through it (because she has that kind of temperament).

DD13's experience in the heterogeneous class was a kid who couldn't do the work and exploded with rage regularly, at everyone. He needed help he was not getting, and it was not fair to him or his classmates.

In middle school they're ability grouped for all academic classes except reading (which boggles my mind, but whatever!) and their experiences with their classmates and the curriculum have been pretty good.

They both notice that the girls in their reading classes obsess over boys, looks, weight, and other people's business. The girls in the gifted classes are too engaged with other topics to really focus on the above topics with the same ferocity as the regular kids. It's definitely there; but gossip is not the center of their universe.