Selection bias is the most powerful force in education • Hacker News Board

Re: Selection bias is the most powerful force in education

#121

Post by stevenwoo » Wed, Aug 16, 2017, 7:04 AM UTC

sien wrote: post #67

Paul-ish wrote: post #60

Earlier quoted context omitted.

> The private school system in Australia saves the government money. Per student funding in the private system is lower than per student funding in the public system. This money is then available to spend more on government schools. Isn't this selection bias again? More difficult (expensive) students may get shunted into the public system.

A number of private schools roughly kick out people in the bottom 10-20% of results. They aren't necessarily that more expensive to teach, the private schools just don't want them. The really expensive kids (say 20K+ per year) are those that are seriously disabled and they almost all go into the government system. But, if the government only has to pay ~1/3 of the cost of about 1/3 of students who are in the private…

There is a weird situation in Texas in the USA. The state is limiting the amount of funding for each local district to 8.5 percent for special education with the end result that families end up going to private schools to get special education. The one family in this school ended up paying 50,000 per year for private school for two kids with a readi ng disability. http://www.houstonchronicle.com/denied/7/

Re: Selection bias is the most powerful force in education

#122

Post by vostok » Wed, Aug 16, 2017, 7:22 AM UTC

alejohausner wrote: post #111

A while ago I read a review of a book called "The trouble with diversity" by Walter Benn Michaels. I was struck by his claim that universities serve to "launder privilege into qualifications". To me, this helps to emphasize the importance of class in America. Rich kids go to Harvard, after graduating from wonderful high schools, helped by private tutors, and, most importantly , knowing that their wealth and their par…

> I succeeded because I'm smart, not because I'm rich.

This is a fair point, but in many cases you need to be rich, hard working, and smart. This is a major improvement over the old system where you just need to be rich.

This is not a uniquely American phenomenon. Top universities in the UK and top grandes ecoles in France are also dominated by the middle class. I'm sure other countries are like that too if not worse.

I think any system with inequality will have this issue. Parents want to help their children and some parents will have a greater ability to do so.

This is not unique to capitalism either. I'm sure those of us from the Soviet Union will be intimately familiar with the concept of блат, which is significantly more pernicious than wealthy children doing better because they have tutors.

Re: Selection bias is the most powerful force in education

#123

Post by AstralStorm » Wed, Aug 16, 2017, 7:28 AM UTC

3131s wrote: post #105

limeblack wrote: post #50

Earlier quoted context omitted.

I went to five high schools growing up and this is not what I experienced. I personally and through others found the exact opposite to be true. Yes you can send students(whether bad or good) to both bad both public and private schools but sending bad students to good public or private schools doesn't make them a good student.

I also doubt that it's meaningfully true. I think the troubled kid would do better in a private school because there are better resources available, and the teachers would not be overburdened with large class sizes filled with similarly troubled students like in a public school. I worked as a reading tutor at an elementary school for a year in the US. It was a terrible, terrible job because of how strictly prescribed…

In a country with actual social services, there should be a feedback channel to identify such cases and help them directly (not necessarily funding but sometimes too).

Of course this won't work in some countries because both socialism is frowned upon and individualism is glorified. You fall because you're a failure not because you were dealt a bad hand by life.

Re: Selection bias is the most powerful force in education

#124

Post by AstralStorm » Wed, Aug 16, 2017, 7:36 AM UTC

ajuc wrote: post #117

> People involved with the private high schools liked to brag about the high scores their students scored on standardized tests – without bothering to mention that you had to score well on such a test to get into them in the first place. This is, as I’ve said before, akin to having a height requirement for your school and then bragging about how tall your student body is. Of course, that's a bad analogy, because aver…

Selection bias makes it also easier to implement special measures. You know where the hot spots are and they are not diffuse.

(FWIW I live in Poland and had a short run with our private education system on both ends.)

What has to be fought is discrimination in employment based on the origin of degrees. All too common. There is enough of this based on connections already.

Re: Selection bias is the most powerful force in education

#125

Post by novaleaf » Wed, Aug 16, 2017, 7:37 AM UTC

The article's hypothetical gubernatorial scenario is a big turn off. It states that Mississippi has higher SAT scores than Connecticut so Connecticut's Teacher Unions are bad.

As the article doesn't at all remark on the suspicious causality of that, it makes me more skeptical of the rest of the article.

Re: Selection bias is the most powerful force in education

#126

Post by AstralStorm » Wed, Aug 16, 2017, 7:39 AM UTC

spunker540 wrote: post #49

richdougherty wrote: post #45

Earlier quoted context omitted.

Are you saying that people should judge schools based on the inputs that go into the schools rather than on any effects the schools produce in their students?

The article points out the high degree of selection bias with schools and how that can make it very difficult to make apples-to-apples comparisons between schools. I was just trying to mention ways to compare schools that won't be affected by the selection bias described in the article.

A proper analysis will attempt to identify such factors and how important they are. Since the sample size is big enough it is not impossible to determine how much of the effect is those other measurable factors.

Selection bias might be measured by the rejection rates on admission (esp. scores rejected)

Re: Selection bias is the most powerful force in education

#127

Post by cefstat » Wed, Aug 16, 2017, 7:56 AM UTC

novaleaf wrote: post #125

The article's hypothetical gubernatorial scenario is a big turn off. It states that Mississippi has higher SAT scores than Connecticut so Connecticut's Teacher Unions are bad. As the article doesn't at all remark on the suspicious causality of that, it makes me more skeptical of the rest of the article.

That’s not at all what the article claims. It presents a hypothetical scenario, based on real SAT average scores, where somebody can reach a very wrong conclusion (teacher unions are bad) based on this data. Then the article proceeds to explain how the difference in the average scores can be attributed to self-selection among students who take the SAT rather than unions. So, the article not only remarks on the suspicious causality but the suspicious causality is the article’s main point.

Re: Selection bias is the most powerful force in education

#128

Post by WalterBright » Wed, Aug 16, 2017, 8:15 AM UTC

"People involved with the private high schools liked to brag about the high scores their students scored on standardized tests – without bothering to mention that you had to score well on such a test to get into them in the first place."

Few private schools have entrance exams. Most only care if the tuition check doesn't bounce.

Re: Selection bias is the most powerful force in education

#129

Post by candiodari » Wed, Aug 16, 2017, 8:20 AM UTC

alejohausner wrote: post #111

A while ago I read a review of a book called "The trouble with diversity" by Walter Benn Michaels. I was struck by his claim that universities serve to "launder privilege into qualifications". To me, this helps to emphasize the importance of class in America. Rich kids go to Harvard, after graduating from wonderful high schools, helped by private tutors, and, most importantly , knowing that their wealth and their par…

The problem with this is how class affects the WILL to be good at school, SAT, college and so on.

If you're high up in the middle class, you have a high-paying job. That means one of three things:

1) medical degree

2) high-end engineer

3) varia (like climbed-up MBAs) (but this is a small group)

Now when it comes to groups in society, the picture looks very different:

Largest groups are non-working people, and workers and tradesmen (from factory workers and construction workers to truck drivers) (total of these groups is like 90% of America)

Both of these groups are famous for disrespecting education, telling anyone who'll listen how college and university degrees are worthless (and for their positions in the world, I'm sure that's true).

And ... surprise ! Their kids mostly don't care about education, and don't score well on SATs (except the ones that figure out they really DO want to in time). Could this be ... because kids believe their parents ?

The "problem" is the entire feedback loop running through society, which mostly is the people itself, not that "rich" people tell their kids to achieve things. You cannot fix this without separating kids from their parents somehow, and you don't want to do that.

The only thing you can do is to prevent the middle class from achieving anything, or anything worthwhile. Which is exactly what is mostly happening in these diversity efforts.

Even that is disregarding the fact that there are already too many college and university graduates to make sure such a degree is definitely worth it. This is a problem akin to "let's make the lowest 50% of the population better off than average".

Re: Selection bias is the most powerful force in education

#130

Post by zeta0134 » Wed, Aug 16, 2017, 8:36 AM UTC

fragsworth wrote: post #106

calebl wrote: post #103

Loved this article. It presents a compelling case that most colleges are providing near-equivalent education , and that the variance is mostly in selection bias. My only objection: at the end, the author takes issue with the fact that it's nearly impossible to get people to take selection bias into account when choosing where to send their kids. However, there's another possible factor that I think parents might be c…

I think the network is overrated. Everyone I've known has had the same experience - immediately after graduating, everyone gets a job, moves far away from one another, and slowly drifts apart from the friends they met in college. You'll get a similar network working at your first job. And then your second job. The group you met in college is of little consequence in the end.

Speak for yourself. My current career in systems administration, a pleasant improvement over my retail start during college, was gained through my network of college friends. I don't keep in touch with them often, but we went to the same programming classes, and know each other's relative strengths. One of my buddies took me to lunch with his friends that work here, and one thing led to another. I still had to apply and go through the technical screening just like anyone else, but just like that I had an "in" and was able to perform a class jump.

Is my experience anecdotal? Absolutely! I didn't even finish my degree, which makes this a weird exception story. On paper, college got me nothing, but in reality, the network of contacts and the life experiences I earned were far more useful to me than the degree I never obtained.