I could bring up a common aphorism: "A chain is only as strong
   as its weakest link".* Ok, I just did. :) I'm focusing on a
   particular because we were going around in circles by
   generalizing.* I see great opportunities being wasted when the
   faster students are either neglected or have to expect to be
   ostracized socially in order to accelerate. Again, I have to
   bring up Case Study rather than statistic; not everything is
   being measured in a statistical fashion yet by somebody; I have
   no figures to give you. My nephew last year, in 3rd grade, was
   purposely trying to do poorly in math and english.* Why?* Well,
   having a good rapport with him as the "odd, smart Uncle", he
   sometimes tells me things he wouldn't tell teachers or parents
   and definitely not a statistician: They wanted to put him on an
   accelerated track for math and english, which would take him
   away from his classmates three times a week.* In his mind, it
   was just like being set aside as one of the 'retarded kids".* It
   struck a chord with me because I had the same experience in 5th
   grade.* The boy is much smarter than me - I have no doubt. Case
   studies - not statistics.* Much murkier territory. ===== Now, I
   didn't know what country you were in; Common Core is a big deal
   in the USA; it's hard to give an overview in a sentence but I'll
   try:* In short, there is a new set of standards that are being
   applied across the country; now, most countries do have an
   national education set of standards; the USA has always lacked
   one. Each state has the right to accept or reject Common Core,
   for we have a peculiar governmental system where the rights of
   States and the rights of the Federal government are allowed -
   and expected - to stay in a continual conflict, in theory,
   teasing out "what's most fair for all" in the process.* Odd
   system, seems to work ok for us. By rejecting it, there are
   consequences; less access to Federal funding, stuff like that;
   and even local individual schools have the right to
   accept/reject it as well. Now, why would any community be
   against a consistent set of federal standards? It's because: as
   with most things, there's more to things than at first meets the
   eye.* There's what you see on paper; a plausable deniability
   that says, "Oh, we regulate the standards, not the testing or
   the teaching" But realistically?* There is a strongly encouraged
   set of testing materials by a single company; There is a limited
   amount of teaching materials available just yet. There is a set
   of sweeping changes, which includes changes to mathematics;*
   Methods for subtraction utilizing addition and estimation which
   have never before been taught in American schools are part of
   the new standard.* New standards, limited amount of testing and
   teaching supplies to support the new standards = a small group
   of companies are in control of how mathematics is taught,
   tested, linking directly to an individual student's academic
   progress. Most sweeping changes to curriculum take place over a
   period of time; they are tested scientifically in a few small
   areas over time; results compared against the past.* But this is
   happening in just a period of 3-4 YEARS. Anyway, this probably
   all boring.* It's local (USA) politics; kids will get through
   whatever system gets thrown at them and they'll manage because,
   most systems are robust enough to basically not be all that bad
   for most students. I apologize for seeming to appeal to
   ignorance; I made an assumption that we were in the same
   country; after 24 years of Internet, you think I'd know better
   than to assume that :P* My opinion is biased, so I can't give a
   purely objective statement about Common Core; I am a source
   material for bias on the issue, not objectivity, as much as I
   may try to be objective about it and I may believe I can be
   unbiased; I know that I'm not. ==== One thing I did find amusing
   is that first you are against the system that tried accelerating
   the "gifted" students (bumping up a year) and now that the new
   system eliminates this you are equally against it. How can they
   win? At the moment, they can't.* I've brought up two case
   studies of people, two generations apart (I'm 42, my nephew is
   9) with nearly identical stories that highlight a problem with
   categorization and separation. However, I cannot bring up case
   studies of the effects of elimination of the category by slowing
   all students down to the same pace through confusion.* Why? It
   hasn't been tested; there are no stories to tell.** Yet.
   Sweeping curriculum changes based on fads in psychology,
   education theory, etc are nothing new to the USA; we've done it
   many times before.* I have only case studies again; my own
   family. My brother is 54 years old.* He was a child in the late
   1960s/70s.* At the time, "New Math" was the thing; they changed
   all of the teaching materials to include abacus style
   mathematics, in the theory that if the Chinese are smarter than
   us in Math, we should teach like the Chinese do.* New materials,
   new teaching, unprepared teachers, unprepared parents,
   unprepared students. Flash forward many years; my brother and I
   start a business together.* I decide that I'll take 10% for the
   operations and he can have 90%, since he does most of the work.*
   And - guess what?* He couldn't calculate 10%. I had to teach him
   how;* He's had a life of math problems that followed him, by
   being part of this "great experiment" that only lasted a few
   years.* I'd love to see if there were follow up studies after it
   was abandoned; I suspect there is very few; we don't like to
   look back on mistakes as a country.** Is it possible there are
   other reasons for his math problems?* Sure.* He works around it
   well enough; he's a whiz at a calculator now (and since I pay
   him, he makes sure to double check I'm paying him properly;
   money is a good motivator for learning). My nieces (in their
   20s) were part of a different math fad; teaching "leafs and
   nodes" in 4th-5th grade in addition if I remember right.* I'm
   the smart guy in the house; they asked for my help.* I had to
   find UNIVERSITY LEVEL mathematics in order to understand it
   myself and learn it within 20 minutes in order to help them; I
   succeeded; but flash forward to today; they didn't gain a "math
   sense" as they tried to do with my brother, and with them.* They
   make do and get by. My nephew: 4th grade now - beginning of
   Common Core implementation, he had several quizes where he got
   poorly graded because he didn't "show his work" (I believe its
   called "state your reasons" now but it amounts to the same
   thing) He does the calculations in his head and very quickly.*
   He can't explain how.* I was/am like that too. He got the right
   answers; but poor grades.* It took me an HOUR of explaining and
   re-explaining - because he really wanted to know - HOW he could
   get poorly graded when he got the answers right. He understands
   how the system works now; how they're not asking for the right
   answers - they need you to show your work so they can show their
   bosses that they were teaching the students how to do math the
   way it says to do in their textbooks. I then gave him some
   tricks on how to do it in his head as he is good at, while ALSO
   "showing his work".* He has to be of dual-mind to do so; but
   that's how things are set up to be; natural talent is
   discouraged, sameness is encouraged. ==== Regarding the systems
   in the next generation being much the same as what came before
   (cycles); in this case, I disagree.* The reason? Having access
   to social networks online; the ability to communicate with
   people not in your town, not in your school, more than just your
   parents and their friends, or the people in your relgious
   institutions or sports teams or shopkeepers; is hugely
   expansive. They have access to alternative opinions and
   viewpoints than that of their local, provincial communities.
   They can look at what's around them and compare themselves to
   other parts of the world, finding out what's the same and what's
   different; from a very young age. Again, case studies: I ran a
   minecraft server for a few years. A young player; 8-9 yrs old
   (with permission of his grandmother), wanted to do a "lets play"
   minecraft video with me (it's deep on my youtube channel, the
   kid's got a wicked sense of humor).* I did it it was fun,* we
   talk publically on social networks from time to time. Now: He's
   become agnostic/atheist from what I can see, despite his
   grandmother, father and family, the community he lives in.* He
   has the internet as his disposal; the ability to find new ideas
   quickly, see what jives with his personality; figuring out what
   makes sense to him. I can't say whether it's good or bad, but
   it's revolutionary to me.* Of course 10 yr olds have gone
   atheist/agnostic in the past I'm sure; but were there
   communities supporting them in their hometowns?* Did they feel
   alone? Or other examples i can state as trends I've noticed: a
   great rise in subcultures and fandoms online of young people of
   Generation Z.* Gender issues; rebellion against the norms in
   their communities; the exploration of such things would have led
   to isolation their individual communities; but being part of the
   Internet?* Huge change - huge. This is part of their
   expectations of reality now. This is part of why I believe that
   big changes will happen; their view of the world and "what's
   possible" is much more expansive in a SINGLE GENERATION than
   those of us who came before and remember. If this has little
   effect on education in the future, I'd be surprised.* The access
   to multiple perspectives that weren't available before is bound
   to have a tremendous impact; but there is no way to study it or
   analogize it that I'm aware of; it's brand new. Perhaps the
   bringing of literacy to an illiterate culture would be a close
   comparison to what I see for the future.