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

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 of the leak (but not beyond). This variation allows me to compare student achievement in schools receiving air filters relative to those that did not using a spatial regression discontinuity design.

In other words, the paper looked at test scores at different schools in different areas on different years and assumed that the only change was the air filters. Anyone who has worked with school kids knows that the variations between classes from year to year can be extreme, as can differences produced by different teachers or even school policies.

Again, I think air filtration is great indoors, but expecting test scores to improve dramatically like this is not realistic. This feels like another extremely exaggerated health claim, like past claims made about fish oil supplements. Fish oil was briefly thought to have extreme positive health benefits from a number of very small studies like this, but as sample sizes became larger and studies became higher quality, most of the beneficial effects disappeared.

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 events and data; what can we get out of it?

Science succeeds when people lean towards the side of cynicism instead of optimism. Scientific research should be read critically.

Critical thinking and skepticism are good, but much of what happens on HN is not that.

Thinking critically includes, most of all, finding value - you need to think critically (and skeptically) to avoid assigning value to things that don't have it, but you must find value. The goal is to build knowledge - just like the study author needs to find knowledge among flawed data, you must find knowledge among flawed studies - and they are all flawed, of course.

Focusing on the flaws and trying to shoot down everything is just craven recreation.

Science is a long game, it's not about sales where you need to sell right now. Extreme results will be attempted to be replicated, which in turn costs a lot of funding. That is money and time, sometimes a whole persons career.

This money and time is taken directly away from funding other, potentially more worthy or more likely to be correct studies.

There is no point of looking at every (flawed) study in the most positive way, unless you have unlimited time and money to pursue every avenue of research.

Often (not always), the studies that are most heavily promoted among the news and in business or politics are really not the best research and other, less visible but more solid research gets ignored in favor of whats popular or what has had good marketing.

This is very frustrating for people doing solid good research, because every so often someone else will come along with wild, exaggerated claims and very little data to back it up, and then gets funding for it.

It takes literal years away from good science just because someone markets and speaks well.

Which is fine in business, but in science this is not something "the market" can or will correct for well, simply because the timespans are so long.

> There is no point of looking at every (flawed) study in the most positive way

This line epitomizes the nonsense in the discussion. I didn't say every study, you can't know it's flawed without seriously examining it, and I didn't say in the most positive way at all.

By using these exaggerations, you damage any serious discussion - you give people nothing to respond to except your emotional state.

What I said was, the point is to build knowledge, and so the way to examine research is to find the valuable knowledge - which includes evaluating the accuracy, etc. of that knowledge. There's no other point to it - we're not awarding tenure here, so there's point in keeping some overall score. We just want to learn what we can.