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Installing air filters in classrooms has surprisingly large educational benefits (2020)

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Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#71

Post by Aurornis »

mmooss wrote: post #30
Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

Based on your comment, the effect could be larger as well as smaller. All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN. Edit: I meant to add: What value can we find in this research? It wasn't published as scripture, the perfect answer to all our problems. It's one study of some interesting event…

> Based on your comment, the effect could be larger as well as smaller.

The reality of any underpowered study could always be “larger as well as smaller”. This statement doesn’t add anything to the conversation.

The mistake is pivoting around poorly structured and underpowered research.

> All research is met on HN by people who know better and will tell you why it's flawed.

This is a misunderstanding. People who know how to read studies will always be aware of the limitations.

There’s a difference between saying “everything is flawed” and pointing out the limitations. Most early research comes with significant limitations like small sample sizes or large cofounders. You have to understand these in conjunction with the results to know how to interpret it.

There’s a cynical approach where people see discussion of limitations, don’t understand it, and instead go into a mode where they think it’s smarter to ignore all criticisms equally because every paper attracts criticisms.

This is just lazy cynicism, though. There are different degrees of criticisms and you have to be able to see the difference between something like a slightly underpowered study, and something like this paper where the authors threw a lot of regressions at a lot of numbers and kind of sort of claimed to have found a trend.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#72

Post by Aurornis »

evil-olive wrote: post #44
Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

> but I also think the extreme results from this study aren't going to hold up to further research. there already is further research. and the results do seem to be holding up. the study you're quoting from is the one linked in the 2nd paragraph of the article. this is from the 3rd paragraph: > But it’s consistent with a growing literature on the cognitive impact of air pollution, which finds that everyone from chess…

> there already is further research. and the results do seem to be holding up.

You’re conflating different results.

The results of the headline study are dramatic in ways that aren’t holding up. The test score increase happened after a single year of putting air filters in class rooms. That’s minimal exposure to purified air for a fraction of the day, 5 days a week, for less than a year of classes.

The other studies are much longe term and look at things like decades of exposure at city scale.

Do you see the difference? The study tried to claim that purifying air immediately improved test scores by dramatic amounts.

There are other serious limitations in the study, like the fact that they can’t even identify which air purifiers were installed or how effective they were. There’s a footnote that says many weren’t even used. There’s a section on air quality monitoring that says they didn’t even detect the VOCs they were trying to filter before they started filtering.

This is the type of study that people implicitly believe because it makes logical sense, but when you read the details you realize that there isn’t much substance in it.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#73

Post by wahnfrieden »

mmooss wrote: post #31
meroes wrote: post #24

Earlier quoted context omitted.

Do you not get massive amounts of dust?

Why would opening the windows result in dust, except where there a lot of dust outside (near a construction site)?

Having any roads/cars around is a major problem. Brake and tire dust. Many people live near roads and traffic.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#74

Post by lazyeye »

mmooss wrote: post #30
Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

Based on your comment, the effect could be larger as well as smaller. All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN. Edit: I meant to add: What value can we find in this research? It wasn't published as scripture, the perfect answer to all our problems. It's one study of some interesting event…

Yes most responses on HN appear to fall into 2 broad categories:-

1. Why this blog post study is flawed and dumb

2. America is bad and shameful.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#75

Post by facile3232 »

Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

> but expecting test scores to improve dramatically like this is not realistic

That seems like a problem for the reader, not a problem with the text. Why would the reader expect this? Is it the use of present tense in the title rather than past tense?

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#76

Post by dang »

Related. Others?

A review of the effects of installing air filters in classrooms - https://news.ycombinator.com/item?id=22006595 - Jan 2020 (26 comments)

Installing air filters in classrooms has large educational benefits? - https://news.ycombinator.com/item?id=22006033 - Jan 2020 (48 comments)

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#77

Post by AngryData »

Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

I would also think there is a bias of schools spending extra money and effort towards student improvements if they are willing to go so far as allocate funding for air filtration systems. A better method would be to just give some schools air filtration for free and see if things help without any other major changes.

To me its like looking at schools that buy newer buses and trying to show new buses improve test scores. When in practice the only schools that are buying any significant number of new buses have far more money coming in than in the past and have a lot more to spend on students compared to other schools, which is way more relevant than what year a kid's bus is made. Maybe better buses would improve scores too, but there is no way to tell if 95% of an improvement is due to other unrelated factors based on funding.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#78

Post by Aurornis »

facile3232 wrote: post #75
Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

> but expecting test scores to improve dramatically like this is not realistic That seems like a problem for the reader, not a problem with the text. Why would the reader expect this? Is it the use of present tense in the title rather than past tense?

What do you mean? The article implies it from the title through the text.

They hedge by saying “could” but like most articles in this vein it goes on to pivot around the outlier study.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#79

Post by amluto »

aetherspawn wrote: post #58

I’m so confused why they installed HEPA filters to filter out LNG and methane. And HEPA filters don’t really scrub CO2 that effectively, even with a carbon membrane, so can we really expect lower CO2 levels? Considering this, what’s the actual takeaway here? Cleaner air (dust/virus free?) is better for productivity? I am asking because I want to buy the same filter for work, but I am doubtful that the $700 HEPA filte…

Having tried to dig into this a while ago, they installed carbon filters.

Most of the stuff for sale as “carbon” filters has too little carbon to do much. You want quite a lot, and, for some gasses, you can get special impregnated carbon or other media.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#80

Post by Aurornis »

AngryData wrote: post #77
Aurornis wrote: post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

I would also think there is a bias of schools spending extra money and effort towards student improvements if they are willing to go so far as allocate funding for air filtration systems. A better method would be to just give some schools air filtration for free and see if things help without any other major changes. To me its like looking at schools that buy newer buses and trying to show new buses improve test scor…

> A better method would be to just give some schools air filtration for free and see if things help without any other major changes.

This is what the study looked at.

The problem was that it wasn’t randomized within schools or across teachers. They also looked at a very limited time window. They also note that some teachers weren’t using the air filters. They also found that the VOCs they were trying to filter weren’t even detected before the filters were used. They also used some questionable regressions to imply larger trends.

The list of problems goes on and on. It’s fascinating how easily people are tricked into pivoting around this one study, though, simply because it’s the one introduced by the headline.

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