Would you kindly elaborate on what you perceive to be the subtleties about IQ? Besides the danger of mistakenly thinking an important factor is the only factor, which is of course a common problem.
About predictive qualities in childhood, take a look at [0], maybe this study is more to your liking. But anyway, this discussion is about the predictability of academic success in young children, so please provide a source for your claim that such predictions are infeasible.
[0] Deary, I. J., Whalley, L. J., Lemmon, H., Crawford, J. R., & Starr, J. M. (2000). The stability of individual differences in mental ability from childhood to old age: Follow-up of the 1932 Scottish mental survey. Intelligence, 28, 49 -55
I think I explained myself poorly. Of course the schools don't measure raw IQ, there are many factors like intrinsic motivation (problematic as a measure in young children) conscientousness (which is a relatively stable character trait) and of course parental pressure which distorts any measurement we can try to make. All I was trying to say that it is possible to judge the potential of the children with adequate accuracy.
> The lowest performers are unlikely to become best, but the middle still changes significantly.
As long as the middle gets sorted into the Realschule, there's no problem ;-)
But more seriously, according to wikipedia[0] IQ is relatively stable beginning at an age of approx. 11 years, so if we compensate for the measurement error with a permeable system I only see two problems: As you mentioned, at this age the brain devolops so rapidly that being the oldest in the class gives students a measurable advantage, but that is an issue for any school system, and as I said in a neighboring comment, overly ambitions parents are meddling too much, but that is a relatively recent phenomenon and a problem unto itself.
Well, as I said, the system is not perfect, which is why there are several paths for "late bloomers" to make it to university. I myself got sorted into Hauptschule, but after a year my grades improved and I switched to Realschule, got a diploma, went to a Fachgymnasium and enrolled in university.
Btw I agree with grandparents argument that the parents' ambition is often the determining factor (as it was in my case) but I would rather try to find a way to assess the students innate abilities more accurately than to simply mix all students together.
> This article is total bullshit and so is the "dual education" model.
This article is about the american system, and compared to taking on student debt, earning an apprentices' salary is an improvement.
>A lot of that is stuff you could be trained for on-the-job in six months or less.
Well, german workmanship has a good reputation internationally, so I would be careful to meddle with a system that produces adequate results.
> Also, don't buy into the German educational model, it's one of the most discriminatory systems in the world, even though it is "free" on paper, it's all about weeding out people at a young age so they're not allowed to attend the "free" university. We have parents suing the teachers of ten-year-olds for the grades they give, because of the impact it can have on their careers.
"One of the most discriminatory systems in the world"? really? Education is free including university, low-income families can get tutors for their children paid for by the Arbeitsamt.
About "weeding out people": Not everybody has the ability to study at a university, so to prevent people from wasting years of their life and paying the opportunity cost that goes with it, it is best to give those people a clear signal which career paths are open to them and which are not.
The parents suing the schools in the link you provided are doing their children a disservice. If you force a child onto a school type above its level of competence, the child will suffer. Being the worst in class is not exactly good for the developing psyche, having no free time because the child needs to study and visit tutors simply to survive academically also takes its toll. And to what end? To start an apprenticeship with abitur? To study at university for a couple of years until you fail to many exams to continue?
Could you elaborate why you think stratification is a bad thing? I think at age 10 you can robustly determine whether or not a student has the abilities for serious academic work, and I believe it's best for the students to get an education that's appropriate for their talents/needs.
Besides, the system (as I experienced it in southern germany) is quite permeable, so even if the sorting is not perfect, students with the necessary academic ability have many paths to university.
[0] Deary, I. J., Whalley, L. J., Lemmon, H., Crawford, J. R., & Starr, J. M. (2000). The stability of individual differences in mental ability from childhood to old age: Follow-up of the 1932 Scottish mental survey. Intelligence, 28, 49 -55