The science of mask-wearing hasn't changed, so why have our expectations? - <AUTHOR> https://fivethirtyeight.com/features/the-science-of-mask-wearing-hasnt-changed-so-why-have-our-expectations/ <comment><USER2> What confuses me is why so much scrutiny is being placed on the practice of wearing a mask. It just hardly seems like much of an inconvenience. And common sense dictates pretty convincingly that it must have _some_ benefit, however small. So then why so much effort into deciding if it works or not?

I suppose there are two answers to that question. One, health officials want to know if masks give a false sense of security so they can spend their time promoting measures that will actually make a difference. Two, folks just want a reason to avoid the minor inconvenience or, worse, have been led to believe that mask mandates seriously impinge upon their rights. My concern is that the most common answer is the second and articles like this only serve to confuse people at a time when we need to accept that we must make small sacrifices to solve this problem.

<comment><USER3> > It just hardly seems like much of an inconvenience.

Not arguing that any of this is a good enough reason to not wear a mask right now, but, I find them pretty darn inconvenient.

It's very uncomfortable. It fogs up my glasses when I'm inside, and covers up a large part of my field of view even when I'm outside. I can't ride my scooter at all because with that field of view loss, I'm worried I'll crash into something. Talking is more difficult, both projecting enough to be heard through the mask and straining to hear others.

I've tried several different masks at this point, so I don't think that's it.

<comment><USER4> When I'm doing construction, I often wear a form-fitting N95 mask (for dust protection) and safety glasses.

The top of the mask, and the nose-bridge of the safety glasses, compete for the same location on the bridge of my nose.

If I layer them so that the mask touches my skin, and the eye glasses rest on the mask, I have no problem with fogging.

If I layer them the other way: the eye glasses' bridge directly on my skin, and the top of the mask resting on the eye glasses' bridge, I get fog.

Maybe you're experiencing this?

I usually avoid this simply by putting my eye glasses on after my mask is in place.

<comment><USER5> It's almost completely dependent on the masks construction. I never had problems with my n95 from 3m, but the kn95 I have is impossible to wear with glasses no matter how I fit it.

The surgical mask a friend got for me in March looks near identical to the pack of masks I got recently besides the color but the one she got me fogs up my glasses while the pack I have now never does.

<comment><USER4> FWIW, the mask I was referring to in the GP is the GVS SPR457 Elipse P100 [0].

(As a side note, I haven't tried many masks, but I find this one extremely comfortable and effective.)

[0] [https://www.amazon.com/gp/product/B013SIIBFQ/ref=ppx_yo_dt_b...](https://www.amazon.com/gp/product/B013SIIBFQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)

</comment></comment></comment></comment></comment><comment><USER6> From an outsider perspective (I'm Canadian), the politicalization of wearing a mask seems like a huge distraction from action that can make a much bigger difference:

* staying home when even a little bit sick

* physical distancing (esp. indoors)

* hand washing

* don't touch your eyes, nose, mouth with unclean hands

* getting tested if having symptoms

* if physical distancing is not possible, then wearing a mask (esp. indoors)

I kind of worry that in a desperate attempt to improve the economy, US governments will continue to ignore the advice of experts and embrace mask- wearing as a panacea.

<comment><USER7> US governments have to deal with the fundamental problem that the US public doesn't want to physically distance anymore. They want to gather with friends and family, eat in restaurants, drink in bars, even hold large public gatherings for their political causes. If the government doesn't offer advice on how to do these things safely, that'll just mean they get done unsafely.

<comment><USER8> Was it ever the plan to maintain physical distancing for the next several years? As lockdowns started, the most alarming projections had us cycling it on and off periodically. Not going cold turkey on all human interaction for the long haul.

<comment><USER9> > As lockdowns started, the most alarming projections had us cycling it on and > off periodically. Not going cold turkey on all human interaction for the > long haul.

The projected initial period of lockdown before going into cycling was longer than even the places that locked down early and reopened late had it, and that was assuming coordinated national response not many places not initially participating in the lockdown.

</comment></comment></comment></comment><comment><USER10> This article has some interesting points, but overall it is click-bait.

The recommendation at the end is, "We don't know how well cloth masks work, so distancing should come first, but masks are likely to work to some extent and not everyone can distance themselves." But for most of the article it talks as if the whole matter is so uncertain no recommendation can be made.

Anyway, the whole idea that we should wait until the science is all settled before we make policy decisions is quite impractical. We are learning as we are fighting the epidemic, and so we have to make decisions before we have full evidence. Indeed, the only way we can learn if masks work to help stop the epidemic is to have some countries mandate them and compare the results with countries that don't. Epidemics are very different than individual diseases. You have to make decisions at the group level, and when it is a new disease you have to do so without really good understanding.

And we know that the countries that have pursued a whole set of rigorous policies that includes face masks have been successful, while countries that are lax, include face masks, have failed. So the smart thing to do is pursue the set of policies that includes face masks, and later on find analyse the data and find out exactly how important they are.

</comment><comment><USER11> I would like to see more discussion around, if the initial viral load is related to the severity of the infection[1].

If yes, then in theory, a mask could provide large benefits, even in absence of a perfect seal around the face.

[1] [https://www.lesswrong.com/posts/3ArEA7tHDXQxE6PED/taking- ini...](https://www.lesswrong.com/posts/3ArEA7tHDXQxE6PED/taking-initial- viral-load-seriously)

<comment><USER12> Absolutely.

The initial disinformation campaign by the western governments (and the CDC and the WHO) that masks are useless for their wearer (due to the shortage of masks, and the fear they won't be enough for the health care personnel) has long lasting effects.

That was an abject lie, and people have paid with their life for that.

The governments now don't know exactly how to turn around and communicate that yes, masks are useful, we've been lying to you all this time, sorry for that, now you can go ahead and wear some.

You can't do an 180 like that, can you? So for now it's "masks are good for the others, but they won't help you. but don't you want to be a good team player?".

<comment><USER13> What is stopping individuals from holding a nuanced understanding of politics similar to this comment?

<comment><USER14> Indoctrination to their social circle (family, friends, etc). You'll become an outsider by expressing opposing opinions.

</comment></comment></comment></comment><comment><USER15> This is a good read "The Masks Masquerade" by Nassim Taleb of Black Swan fame:

"First error: missing the compounding effect" ... "Third Error: Mistaking Absence of Evidence for Evidence of Absence" ...

[https://medium.com/incerto/the-masks- masquerade-7de897b517b7](https://medium.com/incerto/the-masks- masquerade-7de897b517b7)

<comment><USER16> I liked his point that if you believe in "cause no harm" (non-agression), you should wear the mask. It raises issues in what counts as real harm/aggression (wearing clothes someone in society dislikes is technically "harm", but not a harm considered real or aggressive or... I forget the terms).

Then he insults everyone who disagrees with him multiple names and accusations of bad faith (which makes serious discussion undesirable and difficult). I think that's a thing Taleb does (online).

</comment></comment><comment><USER17> Here in NZ, masks were never required. The rationale is that when people wear masks no matter how you explain it they believe they themselves are safe, which makes them get closer to other people (I can't give them the disease) and be less cautious in general (I'm protected). Take the mask away and the only things they have is social distancing and being obsessive about touching surfaces. Which in my experience works very well and it's what the community here focused on.

In the meantime my folks in Maine wear masks and gloves and think now everything is fine we can do anything and go anywhere.

</comment><comment><USER18> As timer notes in another post below, the episode _" Special Episode: Masks and Science"_

talks about the history of masks vis-a-vis Covid-19:

[https://www.cidrap.umn.edu/covid-19/podcasts- webinars/specia...](https://www.cidrap.umn.edu/covid-19/podcasts- webinars/special-ep-masks)

 _In this episode, Dr. Osterholm and host Chris Dall discuss the current science on COVID-19 and cloth masks._

Transcript available at

[https://www.cidrap.umn.edu/revised-mask- transcript-6220](https://www.cidrap.umn.edu/revised-mask-transcript-6220)

</comment><comment><USER19> I wear a mask. I encourage all my friends to wear a mask. It's a very low cost, with large potential upside. There's no good reason _not_ to wear a mask.

But I am also interested in the pure science & am asking strictly from that point of view. Again, I am __not __suggesting we don 't need to wear masks.

I found this report on the CDC website that states:

"Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures _did not support a substantial effect on transmission of laboratory-confirmed influenza_ "

(emphasis mine)

[https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article](https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article)

I'm aware it's for influenza & not COVID-19, but most research, including evidence suggesting we should wear masks, is based on research done on influenza. I think it's reasonable, given the paucity of COVID-19 data and we have to do something, and given they're both RNA viruses, experts feel it's reasonable as well.

My conclusion from above is that while we should still definitely wears masks, it's unlikely wearing them will see a noticeable change in R0, which is what we need to really open up. I.e., opening with mask compliance probably isn't going to work, and we need people to stay home.

I'm not an expert, so would to love to learn if I've got anything wrong. Thanks in advance.

</comment><comment><USER20> The virus is in the same class as some common colds. It's not "going away". If people are concerned about it they should use a real mask designed to filter viruses[1]. Instead, the population is being conditioned to force medical procedures on other people. Forever.

The "flatten the curve" thing was predictably re-goalposted.

There are strong financial incentives to keep people irrationally in a state of fear. After this, there will be the next.

This keeps getting ignored: What is the non-COVID-19 pneumonia # for 2019-2020?

CDC Influenza and pneumonia deaths by influenza season and age: United States, 2008–2015: [https://www.cdc.gov/nchs/data/health_policy/influenza-and- pn...](https://www.cdc.gov/nchs/data/health_policy/influenza-and-pneumonia- deaths-2008-2015.pdf) (these are not estimates, see the footnote)

      CDC #'s 2015-2016
      Flu: 7,961
      Pneumonia: 131,858
      All: 1,769,940

[1] [https://news.ycombinator.com/item?id=22232633](https://news.ycombinator.com/item?id=22232633)

<comment><USER6> > If people are concerned about it

Until more is learned about covid-19 people should be concerned. Where the disease is out of control, hospitals are filling up and many people in need of health care are suffering as a result.

BTW, at least in Canada, the number of deaths due to covid-19 has been concentrated most in long-term care homes. These are also places where deaths due to pneumonia and flu are common. We're learning now that the quality of care in these homes has been insufficient to deal with covid-19. All of the measures that are now in the works to improve the quality of care in those homes should have the side-effect of reducing deaths from other infectious diseases in the future.

<comment><USER20> The excess death stats are accessible to us all. What's the non-COVID-19 pneumonia # for 2019-2020 so far?

It's nonsensical to expect everyone to agree, those that want a mask, should use one for viruses. This is like pretending the cold is going away, and we must all obey until that happens. Wont happen.

As you mention, fixing the situation of the vulnerable is the way. Quite possibly would have been better response in the first place.

Viruses are only getting easier to engineer. Shutting down the country only makes them _more_ valuable.

</comment></comment></comment><comment><USER21> "Martin worried that wearing masks might lead people to feel more safe than they actually were — and make choices that increased their risk of contracting or transmitting COVID-19." \- I don't see people wearing masks jumping into my face. It's people who're feeling safe for other reasons, that do. People who don't see there's a pandemic. People who think it's all made up. People who feel invincible or who're thinking they can show-off as invincible to impress others. Those people don't wear masks and throw one Corona Party after another. I'd assume that most people wearing a mask care more deeply about others than those who don't. So, wearing a mask is also a statement. And it's got almost nothing to do with politics.

</comment><comment><USER22> > "... a public health and disease expert who is worried that mask > effectiveness is being over-hyped..."

Medical professionals have their own sources of information (just talk to a doctor about hand washing vs. hand sanitizer).

Then I assume the concern is some members of the public are taking risks while wearing masks, thinking they are more safe than they really are? I don't understand the concern, because if you're really concerned about the virus you're staying home. If you're cavalier about the whole thing, then you're likely standing <6feet and doing other "risky things". And finally, for everyone else there are the simple rules.

This seems totally different than, say, the controversy about the anti- malarial drug, which had severe potential side effects.

What am I missing?

</comment><comment><USER23> So what is needed to get to that certainty? What research is being done or must be done?

<comment><USER24> Should we even bother, now that masks are becoming easier to purchase?

<comment><USER25> Given that we're heavily inconvenienced by the masks and other measures, we should find out how well they work so we can focus on the stuff that helps the most.

</comment></comment></comment><comment><USER26> The CDC best estimate is that US has 20M+ covid cases right now ( [https://www.nbcbayarea.com/news/coronavirus/cdc-says- covid-1...](https://www.nbcbayarea.com/news/coronavirus/cdc-says- covid-19-cases-in-us-may-be-10-times-higher-than-reported/2315636/)) . That number has beem reached with all the masks wearing and lockdowns.

So, what is the difference between the expectations in case of mask wearing vs. not wearing by the end of the year? Even with masks wearing and lockdowns we're probably talking about high tens of millions or even 100M for US. Can it be higher without masks and lockdowns? Spanish flu infected just under one third of total population. For covid, New York had probably reached about 2M cases (~20% of population) and the infection rate went down after that. Using that model of 20% (and NY has much higher population density) it means 70M infections for the whole US. Given how we've already reached 20M+, i think that number will be reached no matter what in a few months (give or take a bit depending on masks, lockdowns, etc.), well before wide availability of vaccine.

So, it is really not about whether masks work, it is about whether it makes any noticeable difference in the current situation. I personally was for total population mask wearing, temp checking, etc. back then in Dec/Jan/Feb because back then we had a chance to stop the spread. These days i just don't see any arithmetically consistent way to avoid the described above scenario and stop the current flooding/tsunami.

<comment><USER27> You assume here that NYC's numbers went down via some property of the disease, not a lockdown being observed by the whole city along with high mask usage. Letting this "run its course" would spike NYC and the whole US far above 70M cases. We would easily be looking at 500,000 dead at least even with how we've learned to decrease the death rate. That death rate would also go up as we stop flattening the curve, as we saw happen quickly with Texas.

NYC has had decreasing numbers despite large outdoor protests, which had high mask usage. In a week or two there will be some numbers on how Phase II reopening is going in an area with high mask usage as well which should be another good data point.

Here are some actual interesting scenario tools for controlling the virus even as it runs its course: [https://ncase.me/covid-19/](https://ncase.me/covid-19/)

As a note, a big factor here is that it appears that antibodies may only last for 2-3 months which breaks some of those recovery models. If that is true, without any mitigation and even with most at-risk people dying off earlier, we could still end up losing .1% - 1% of the population every 3 months until we have a treatment or vaccine. I don't like how those numbers look even if we manage to get a vaccine in 12 months.

<comment><USER26> >some property of the disease

it seems that only some share of people is susceptible to a given virus like covid, flu, etc. (for whatever reason, like some genetic characteristic or for example presence of antibodies from some other virus which happen to help here). Say for example half of the population, 50 out of 100. So once 20 people got it, there are 30 left to be infected while all the others - 70 - can't participate in the infection spread, and 70% is pretty close to herd immunity.

Add to that the estimates that herd immunity for covid can be even less than half [https://www.usnews.com/news/health- news/articles/2020-07-02/...](https://www.usnews.com/news/health- news/articles/2020-07-02/could-threshold-for-covid-19-herd-immunity-be-lower- than-thought) \- that would explain the infection rate drop in NYC.

<comment><USER27> > Say for example half of the population, 50 out of 100.

I think you're confusing susceptible and immune. If the antibody numbers are legit, then the asymptomatic rate is around 90%, but that's not the full story. You have to remember that asymptomatic people still spread the virus, so this plays differently in herd immunity modeling. You're still looking at a 1% average death rate in NYC too given those numbers.

That 50% of people you mentioned is not about symptomatic - they must also not be able to transmit. Otherwise using a SIR model or similar there's still 80% of the population that can catch and infect others. I have seen nothing about such natural immunity in people even in small numbers, let alone at 50% of the population. That assumption is doing a lot of legwork in your herd immunity claim.

At best, your assumptions still means we need to accept just under a million deaths. At worst, even with no increased death rate due to hospital load, that's closer to 3 million. When other countries have shown clear alternatives by taking measures that don't lead to 1% of their population dying (such as Germany at 0.01% so far), one of which is mask usage, I don't see how there's harm in the policy when it could mean literally saving millions of lives.

All of that relies on antibodies lasting, which doesn't seem to be guaranteed[1], as I pointed out in my post before. That can make this much worse if/when people begin to catch it again.

[1][https://www.cidrap.umn.edu/news- perspective/2020/06/chinese-...](https://www.cidrap.umn.edu/news- perspective/2020/06/chinese-study-antibodies-covid-19-patients-fade-quickly)

<comment><USER26> NYC made masks law on April 15. Germany somewhere around a week later.

> I don't see how there's harm in the policy when it could mean literally > saving millions of lives.

there is no harm. I wear my. Even though all the facts and math shows that it doesn't make any noticeable difference at this point.

>At best, your assumptions still means we need to accept just under a million deaths

accept or no accept, covid doesn't care. Anyway, we have already "accepted" it by letting it develop into the current scale. I think original Fauci deaths estimates - up to 250K - made under obvious political pressure to voice lower numbers than he'd do otherwise - is pretty close. From the current 20M+ we'd get 3-4x with death rate falling, thus we'd get into 250K-500K range. I don't see how masks or lockdowns, which haven't been able to stop us from the 10000x jump - tens/hundreds cases into tens of millions - are going to stop us from the 3-4x or even 10x (if the 10x were possible in the current situation which it isn't because the herd immunity threshold looks to be significantly lower)

<comment><USER27> > NYC made masks law on April 15. Germany somewhere around a week later.

And you left off that NYC's cases dropped the entire time those mask policies were in effect. We didn't isolate for it as the lockdown was in place, but there's at the very least a positive correlation, and the lack of spike from the protests supports that too. I don't see why you jump to defeatism from that evidence.

You're assuming people in most of the US paid attention to the laws and advisories. In Florida for example, mask usage was incredibly low and has caused the spike there. Same for Texas. We don't know if masks would stop the initial jump because we didn't use them. All evidence from other countries points to the conclusion that they do help in a meaningful way.

If you're saying you don't believe the American populace is capable of following instructions, you might be right, but if we actually enforced and practiced mask policies, it very much appears it would make a meaningful difference.

<comment><USER26> >And you left off that NYC's cases dropped the entire time those mask policies were in effect.

you're right. I somehow was under impression that the peak cases were a month later there. Lets see. I'm still really not optimistic giving the current scale of the spread.

</comment></comment></comment></comment></comment></comment></comment><comment><USER28> It's been really interesting to watch this pandemic from Japan, where I've been for the last ~3 months. I am an American citizen.

Walking around Tokyo this week I'm still seeing mask rates of >95%. Lockdown ended about 2 weeks ago.

In America, mask-wearing carries a different set of social signals. It seems that not wearing a mask is perceived, by some, as a signal of one's virility and freedom.

The article makes this all pretty clear, but the comments here are getting bogged down in "but the data says masks are/aren't effective". The point is that the data doesn't matter. Mask-wearing is determined by social/political expectations and signaling, not by data.

If a study came out tomorrow that said mask-wearing reduces transmission by 95%, Trump still wouldn't wear one. Looking for a silver bullet study to prove a point either way is a waste of time at this juncture.

Apparently, asking Americans to show that they care about the health of another American via a very low-impact signal (the $10 it costs to get/make a mask, the minor inconvenience of wearing one) is too much.

How can a society solve any size of a problem when it cannot be bothered to put a piece of paper or cloth on their face for the possible benefit of another? If your political climate makes such a minor gesture controversial, how will you solve any meaningful issue where your factions disagree?

How do you get Americans to care about the health and welfare of other Americans?

<comment><USER29> > Walking around Tokyo this week I'm still seeing mask rates of >95%. Lockdown > ended about 2 weeks ago.

I currently live in Asia and have been for many years, I am from a western country. I think in Asia, face masks are just a fact of life, including pre- covid. There is/was an expectation that if you are sick, then you should probably wear a mask. Given that a lot of cities are crowded, many wear masks also not to get sick.

As a westerner, I understand the negative connotations of wearing a mask, it is not a part of "normal life" in many countries. But life has changed, people should get used to it. Americans should just look at the stats to know that there is a problem. This isn't an attack on their freedoms, it is an attempt not to save their life, but the life of a fellow American, by preventing the spread.

While China may have been the epicenter of the virus, the spread is the responsibility of the citizens of the secondary country.

</comment></comment><comment><USER30> This seems like it is casting uncertainty when there is really good evidence that wearing masks is effective.

[https://www.theguardian.com/commentisfree/2020/apr/04/why- we...](https://www.theguardian.com/commentisfree/2020/apr/04/why-wear-a-mask- may-be-our-best-weapon-to-stop-coronavirus)

<comment><USER31> On the contrary, there's actually very little evidence that masks are effective for the general public. Particularly for cloth masks, the evidence is essentially non-existent. You're citing an article by Jeremy Howard, who is quoted in the OP, and whose opinion is directly rebutted.

Michael Osterholm of CIDRAP has written a rather scathing summary of the data for cloth masks, and the political and social machinations that have gotten us where we are. He calls out Jeremy Howard as a particularly vocal spreader of scientific misinformation on the topic:

[https://www.cidrap.umn.edu/covid-19/podcasts- webinars/specia...](https://www.cidrap.umn.edu/covid-19/podcasts- webinars/special-ep-masks)

(edit: how can you possibly downvote a link to a factual source that is _cited in the article_? Consider your bias.)

<comment><USER24> In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks. Up until the quarantine began the reasonable assumption was that if you needed a mask you wore the one appropriate to your task. I don't think cloth masks were in widespread use until these masks became scarce.

Maybe some studies are happening now. Even so, it probably makes more sense to encourage people to purchase more reliable masks.

<comment><USER31> _" In my opinion, it's unreasonable to expect that there would be studies on the effects of cloth masks."_

That's fine, but there are lots of plausible interventions that have little/no evidence, and we don't mandate those by law. Why this one?

For example, the Lancet study commissioned by the WHO found that _eye protection_ is about as supported by the available literature as surgical masks. Why aren't we all required to wear goggles?

I believe that "science" should not be used to mandate actions that have no scientific data backing them.

 _" it probably makes more sense to encourage people to purchase more reliable masks."_

The issue there is still shortages. I don't buy surgical or n95 masks, because other people need them more than I do.

<comment><USER32> > For example, the Lancet study commissioned by the WHO found that eye > protection is about as supported by the available literature as surgical > masks. Why aren't we all required to wear goggles?

Because masks are being recommended to work on _outgoing_ virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument.

<comment><USER31> _" because masks are being recommended to work on outgoing virus. Unless you've evidence respiratory viruses spread significantly via jets of air emitted via your eyeballs, this is a weird argument."_

If you read the Lancet paper, you'll find that they pooled papers for source control and PPE together to arrive at their conclusions. In fact, _most_ of the papers they used in that meta-analysis were for surgical masks used as PPE (personal protective equipment) in a medical setting.

In other words, the advocates for masking are doing the same thing that you're saying is weird. If you try to break the analysis down according to specific lines of evidence (i.e. source control for the public), you quickly find that there's not enough data to draw any conclusion.

On the other hand, the argument _in favor_ of this kind of pooling is straightforward: if your end goal is to reduce transmission of a virus, and you find that goggles are highly effective at _preventing infection_ , then it doesn't matter very much. Tell everyone to wear goggles instead, and forget about the masks. Transmission will still be reduced.

<comment><USER32> Medical settings are concerned largely with PPE that protects the staff, and a number of healthcare procedures are aerosol-generating.

Mask wearing for COVID is targeted at reducing likelihood of spreading to someone else.

> If you try to break the analysis down according to specific lines of > evidence (i.e. source control for the public), you quickly find that there's > not enough data to draw any conclusion.

We're going to get a lot of data soon, but for the time being, it's probably best to err on the side of "something that stops droplets probably helps stop a disease spread by droplets".

<comment><USER33> We already have lots of data. Here's the Lancet paper: [https://www.thelancet.com/journals/lancet/article/PIIS0140-6...](https://www.thelancet.com/journals/lancet/article/PIIS0140-6736\(20\)31142-9/fulltext)

> Our search identified 172 observational studies across 16 countries and six > continents, with no randomised controlled trials and 44 relevant comparative > studies in health-care and non-health-care settings (n=25 697 patients). > Transmission of viruses was lower with physical distancing of 1 m or more, > compared with a distance of less than 1 m (n=10 736, pooled adjusted odds > ratio [aOR] 0·18, 95% CI 0·09 to 0·38; risk difference [RD] −10·2%, 95% CI > −11·5 to −7·5; moderate certainty); protection was increased as distance was > lengthened (change in relative risk [RR] 2·02 per m; pinteraction=0·041; > moderate certainty). Face mask use could result in a large reduction in risk > of infection (n=2647; aOR 0·15, 95% CI 0·07 to 0·34, RD −14·3%, −15·9 to > −10·7; low certainty), with stronger associations with N95 or similar > respirators compared with disposable surgical masks or similar (eg, reusable > 12–16-layer cotton masks; pinteraction=0·090; posterior probability >95%, > low certainty). Eye protection also was associated with less infection > (n=3713; aOR 0·22, 95% CI 0·12 to 0·39, RD −10·6%, 95% CI −12·5 to −7·7; low > certainty). Unadjusted studies and subgroup and sensitivity analyses showed > similar findings.

The important bit here (for everyone saying we have great evidence that masks work) is that "low certainty" bit. That's GRADE, and it means "low certainty (our confidence in the effect estimate is limited; the true effect could be substantially different from the estimate of the effect);" So, maybe masks are substantially less, or more, protective.

<comment><USER32> Like I said, I'm not doing the dance again.

Last time it was pointed out "low certainty" doesn't mean what you imply it does ([https://news.ycombinator.com/item?id=23434344](https://news.ycombinator.com/item?id=23434344)) you let it sail on by.

<comment><USER33> Here's what low certainty grade results mean: "low certainty (our confidence in the effect estimate is limited; the true effect could be substantially different from the estimate of the effect);".

Just so we're clear: you've never linked to research to support any of your points, because you're not able to, are you?

<comment><USER32> > Just so we're clear: you've never linked to research to support any of your > points, because you're not able to, are you?

I did. 28 days ago.

[https://news.ycombinator.com/item?id=23434255](https://news.ycombinator.com/item?id=23434255)

[https://news.ycombinator.com/item?id=23434053](https://news.ycombinator.com/item?id=23434053)

> Here's what low certainty grade results mean: "low certainty (our confidence > in the effect estimate is limited; the true effect could be substantially > different from the estimate of the effect);".

You're acting like its definition is "it's probably the opposite, and thus is evidence for my argument".

<comment><USER33> And last time you posted those links I pointed out that they were for the same paper and the paper doesn't support your point.

Here's someone explaining what GRADE means:

[https://twitter.com/dnunan79/status/1269014574478626819](https://twitter.com/dnunan79/status/1269014574478626819)

"I teach GRADE

If something has "low quality" evidence, it means the observed estimate is highly likely to be different from the truth.

Face masks = low quality evidence.

So what's the point of GRADE if we can conclude "evidence shows"?"

EDIT: Your link even says this

> Further high-quality research, including randomised trials of the optimum > physical distance and the effectiveness of different types of masks in the > general population and for health-care workers' protection, is urgently > needed

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER34> [https://medium.com/p/4ef05aa357c5?source=linkShare-72308c464...](https://medium.com/p/4ef05aa357c5?source=linkShare-72308c464041-1586107578)

</comment><comment><USER35> The "science" of mask wearing is plagued by redundant and irrelevant abstract mathematical concepts.

A mask is a membrane (not perfect, of course) and this is how it must be properly modelled.

It is that simple - just use proper (right) abstractions.

All the sophisticated statistical extrapolations is just flawed bullshit.

</comment><comment><USER36> I just want to point out all the people who say "It's about protecting others, not yourself" or some variation _are part of the problem_! That can be said about the random diy cloth masks, but for everything else:

The science of masks hasn't changed...

N95 – Filters at least 95% of airborne particles. Not resistant to oil.

Surgical N95 – A NIOSH-approved N95 respirator that has also been cleared by the Food and Drug Administration (FDA) as a surgical mask.

N99 – Filters at least 99% of airborne particles. Not resistant to oil.

N100 – Filters at least 99.97% of airborne particles. Not resistant to oil.

R95 – Filters at least 95% of airborne particles. Somewhat resistant to oil.

P95 – Filters at least 95% of airborne particles. Strongly resistant to oil.

P99 – Filters at least 99% of airborne particles. Strongly resistant to oil.

P100 – Filters at least 99.97% of airborne particles. Strongly resistant to oil.

I've been wearing a p100 respirator that makes a good seal to protect myself, and been changing out a small piece of cloth on the out-valve to protect others. Please, stop perpetuating the myth that masks don't protect you. Of note is that while many of the higher rated masks tend to be tested at .3 microns, this is often a buffer and real world they tend to filter about .1... and the virus is said to be .12+ micron.

So if you can, I would suggest getting your hands on n100 or p100, preferable use an oximeter to make sure you have the physical fitness needed to force the air through, but if you are doing very small timeframe adventures this becomes less of an issue. Something that makes a good seal is ideal. Guys, you should heavily consider shaving. There is a reason in the military NBC training they started requiring with only a few exceptions, shaves... and no, the military gas masks will not work for this application unless you get the specific filters for this application (if you do, they would be great since they integrate the eyepro), which have a much wider ranger to select from than the above I reference...

note: it is also very important to verify you haven't been sold a fake product

[https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part...](https://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/default.html)

<comment><USER37> I think that the whole "masks don't protect you they protect others" spiel was designed to save face, because authorities were adamant about masks not working until March. Of course they protect the wearer....otherwise healthcare workers wouldn't use them.

<comment><USER38> I'm pretty sure health care workers wear them primarily to protect others. This is what my health care worker friends have told me (long before covid). Sneezing on someone mid surgery would be pretty bad for the patient, not really for the surgeon.

I think the reason people say it's more for others than yourself is because it's actual pretty rare to catch a disease by breathing it in. Much more often you catch it when it gets on your fingers and then you touch your eyes/nose/mouth. I think that's still at least partially true with covid.</comment></comment></comment>


A Look At The Next iPhone, As It Leaks Across The Internet - <AUTHOR> http://techcrunch.com/2010/04/19/a-look-at-the-next-iphone-as-it-leaks-across-the-internet

<comment><USER2> See also <http://news.ycombinator.com/item?id=1276732>

Some comments, and much scepticism.</comment>


Apple Snags Former Defense Contractor for Board Position - <AUTHOR> http://www.pcmag.com/article2/0,2817,2372885,00.asp

<comment><USER2> Some of Northrop Grumman's more interesting accomplishments under Ronald Sugar's tenure:

Acting as goodwill ambassadors to the people of Iraq:

 _Northrop Grumman's subsidiary, Vinnell Corporation, has been catching a lot of flack lately. They landed a $48 million contract with the US occupational authority to train the Iraqi National Army, but have botched the job so badly that the Jordanian Army has recently been brought in to take over the job._

[http://www.corpwatch.org/article.php?list=type&type=11](http://www.corpwatch.org/article.php?list=type&type=11)

Lobbying Congress on the Armenia genocide bill:

 _Corporate America typically hires lobbyists to pressure Congress on taxes and trade rules. But in an unusual -- some say risky -- move, five military contractors and an energy company have stepped into a fight over whether the U.S. should label Turkey's slaughter of a million Armenians nearly a century ago as genocide._

 _The six companies have strong ties to Turkey, a key strategic ally of the U.S. in Mideast peace efforts and the fight against terrorism. None would state their position on the House resolution, but industry analysts and others said they likely lobbied against the measure to show support for Turkey, an important market for weapons and industrial products._

 _"They don't want to be seen opposing a resolution that has a very evident human rights element," said Rouben Adalian, director of the Armenian National Institute, a Washington research organization. "It would put them on the side of denying history and denying genocide."_

<http://www.corpwatch.org/article.php?id=15404>

Helping the Pentagon build (probably illegal) databases of "suspect domestic activity" like anti-war protests:

 _Two years ago, the Defense Department directed a little known agency, Counterintelligence Field Activity, or CIFA, to establish and "maintain a domestic law enforcement database that includes information related to potential terrorist threats directed against the Department of Defense." Then- Deputy Secretary of Defense Paul Wolfowitz also established a new reporting mechanism known as a TALON or Threat and Local Observation Notice report. TALONs now provide "non-validated domestic threat information" from military units throughout the United States that are collected and retained in a CIFA database. The reports include details on potential surveillance of military bases, stolen vehicles, bomb threats and planned anti-war protests. In the program's first year, the agency received more than 5,000 TALON reports. The database obtained by NBC News is generated by Counterintelligence Field Activity._

 _CIFA is becoming the superpower of data mining within the U.S. national security community. Its operational and analytical records include reports of investigation, collection reports, statements of individuals, affidavits, correspondence, and other documentation pertaining to investigative or analytical efforts by the DOD and other U.S. government agencies to identify terrorist and other threats. Since March 2004, CIFA has awarded at least $33 million in contracts to corporate giants Lockheed Martin, Unisys Corporation, Computer Sciences Corporation and Northrop Grumman to develop databases that comb through classified and unclassified government data, commercial information and Internet chatter to help sniff out terrorists, saboteurs and spies._

 _One of the CIFA-funded database projects being developed by Northrop Grumman and dubbed "Person Search," is designed "to provide comprehensive information about people of interest." It will include the ability to search government as well as commercial databases. Another project, "The Insider Threat Initiative," intends to "develop systems able to detect, mitigate and investigate insider threats," as well as the ability to "identify and document normal and abnormal activities and 'behaviors,'" according to the Computer Sciences Corp. contract. A separate CIFA contract with a small Virginia-based defense contractor seeks to develop methods "to track and monitor activities of suspect individuals."_

<http://www.informationliberation.com/?id=4038></comment>


Ask HN: Is Product Market Fit Just Luck? - <AUTHOR> I you read some of the lean startup type books, you get the idea that you need to speak to customers first.
Pat Flynn had this idea of making a market map in his book Will It Fly.  I think this is similar to Amy Hoy's Sales Safari.  The idea is to go around online forums and other places where users are having discussions.  You look for pain points by certain keyword questions.
These method works great when there is a forum and a good number of people discussing a problem.   But if you recall the 1% rule, there are 99% of the people not talking online and contributing content.
Rob Walling had another method where he used the Google Ad tools to gauge search volume.  I am not sure if this really works anymore given changes to those tools.
This makes me wonder if finding product market is really just luck.  What is your take on this?  Is it luck or are there better methods? <comment><USER2> It seems that a lot of the best products are built by people who themselves would be end users. IMO product market fit research is great for someone outside of an industry, trying to start a new industry, or with deep pockets to spend on researching the market. As a first timer or a small business owner, you're better off targeting your own real pain points.

<comment><AUTHOR> It still seems like luck if you have different pain points than the majority in that industry.

<comment><USER2> Absolutely. Life is luck, starting from where you are born and who your parents are.

</comment></comment></comment><comment><USER3> I have an entrepreneur in my family. After watching him build businesses I have realised these two things when it comes to understanding what business to start:

\- Trying out multiple projects(however small they may be) opens a lots of doors because people start talking to you about their own pain points! and

\- Luck favours the bold; you need to take risks.

And one thing is very important, "Get out of the building and meet people".

So is there a luck factor in PMF? No, there isn't. You find PMF when you try different things while at the same time talk to people(past, present and prospective customers).

I will give you an example. The person I mentioned above initially started with a small business of supplying toiletries to businesses(big and small). One day one of his customers asked him whether he would be able to supply instant tea and coffee mix to the business. He agreed and started supplying tea and coffee. Went to other businesses and asked if they would be interested. Got sizeable amount of customers. One day, one of his tea and coffee customers, a defence establishment, asked him if he could arrange student visits to their facility for educational purpose. He agreed. Then went to lot of other schools and businesses and asked them if he could help them arrange student visits. He got success in that! Now he has recently started building a park(with space theme) for students.

So, if you look at the journey it is not some magic with which one finds a PMF. The entrepreneur has to go out and talk to people so that s/he receives the right signals. And then be bold enough to take the risk to start working on the problem.

</comment><comment><USER4> Everything in business has an element of luck.

But if your product doesn't provide value or customers aren't willing to pay for it I'm not sure you can overcome that with luck.

I would look at it more as you can have product market fit and your product not grow fast or even fail without some luck.

But your product will eventually fail without product market fit even with lots of luck.

Check out Rob Walling's new podcasts.

8 Things You Must Know When Launching Your SaaS and 10 Things You Should Know As You Scale Your SaaS.

Sign up for the email list here: [https://www.startupsfortherestofus.com/](https://www.startupsfortherestofus.com/) And receive two never-before-released podcast episodes: 8 Things You Must Know When Launching Your SaaS and 10 Things You Should Know As You Scale Your SaaS.

Listen to 10 Things You Should Know As You Scale Your SaaS.

The part about product market fit starts around 2:00.

Rob talks about using this method to quantify your product market fit.

[https://justinjackson.ca/product-market-fit- survey](https://justinjackson.ca/product-market-fit-survey)

</comment><comment><USER5> I've had that question mulling around in my head for a few years.

Like others have mentioned, of course there's an element of luck. It helps to have a product that fits the zeitgeist.

But in my experience, the remaining 99% is all working smart and understand what and the "why" of the problem at hand.

The Google Ads technique is good, but only if you're working on a product with a known problem. For anything new... it probably won't be much help on it's own. It's useful though if you use to see how people try to solve known problems.

Best resources hands down IMO for understanding 0 to PMF are: The Lean Product Playbook by Dan Olsen. Gives a good view on how products fit with the market. If the problem space is wobbly, the solution space will suck. The Mom Test by Rob Fitzpatrick (my favourite). Excellent book on user interviews. It's so good that I made a primer out of it: [https://gum.co/DeSxL](https://gum.co/DeSxL) The PMF Engine by the founder of Superhuman: [https://firstround.com/review/how-superhuman-built-an- engine...](https://firstround.com/review/how-superhuman-built-an-engine-to- find-product-market-fit/) It's a more quantifiable way of approaching it.

</comment><comment><USER6> not "just" luck, but luck plays a large part too. That doesn't mean you can't beat luck as an unlucky person. You just have to try many times.

luck = (size of success / # of attempts)

which translates to:

size of success = (# of attempts) * luck

if your luck is low, you can compensate for it by working hard.

</comment><comment><USER7> There's accidental product market fit where you make a product for some purpose and it turns out that a completely different use case is discovered by users, or a narrow subset that you didn't imagine/target gains traction.

Then there's product market fit where you started with an identified group of users and in some way made their jobs/lives easier. What the product was to be was an open-ended journey to understand what they do, why it matters, and how it can be better. Luck still plays a lesser role here, where if you're actually only in communication with a very small group and have no easy means to find/target, demonstrate value, some unplanned event connects the dots.

</comment><comment><USER8> Mining information from forums can be useful, but that's just scratching the surface. I suggest reading this:

[https://www.amazon.com/Four-Steps-Epiphany-Successful- Strate...](https://www.amazon.com/Four-Steps-Epiphany-Successful- Strategies/dp/1119690358)</comment>


Islam is not a religion like any other, here's why. - <AUTHOR> http://www.reddit.com/r/atheism/comments/100ul6/islam_is_not_a_religion_like_any_other_heres_why/

<comment><USER2> Islamophobia is a virulent issue, particulary in Europe. There are a number of reasons behind this (most prevalently Continental Europe's lack of a history of immigration and integration, which has caused struggles throughout the Continent since large scale immigration from non-European countries began in the late 60s and 70s), but that doesn't excuse it.

I struggle to see why this merits a link. That said, there's a parallel I love to draw when people make this particular argument: is what they're saying about Muslims all that different from what 19th century Americans said about Italian and Irish immigrants and their "allegiance to the Pope above country"? Xenophobia is nothing new.

<comment><USER3> Not to talk about present day extremist christians, who deny evolution. Not much of a muslim invention.

<comment><AUTHOR> I was baffeled when hearing that for the first time. I've attended a Catholic primary school, but it never occurred to anyone until the last few years that the story about God creating everything and evolution theory conflicted. We've been told both. I was amazed when hearing about the evolution theory not being believed on some (many? I don't know) schools in America (though it might have been anywhere I guess).

<comment><USER2> I don't know the figures offhand, but the percentage of Americans who don't believe in evolution is...disheartening to say the least. Hell, it's downright embarassing when you compare the percentage of Americans who don't believe in evolution to the percentage in other 1st world countries. Yay evangelical fundamentalism!</comment></comment></comment></comment>


More Layoffs for Intuit as Company Continues Realignment - <AUTHOR> http://techcrunch.com/2015/08/25/more-layoffs-for-intuit-as-company-continues-realignment/

<comment><USER2> > "Intuit has had a tough run in recent weeks. Following its earnings report > last week, the company's stock fell sharply."

With the type of week the US and the rest of the world has had in the stock market I think a drop in stock prices should be taken with a grain of salt.

</comment><comment><USER3> Intuit is in trouble. There are several competing products eating its lunch.

TaxAct is a good example of a competitive alternative to Turbotax. I used to do my taxes with TurboTax, but got tired of the yearly price increases and the movement of useful sections of the 1040 form to higher priced versions. A couple of years ago, I switched to TaxAct which provides everything for 1/5th the cost of the best TurboTax package.

I dumped Quicken 10 years ago due to the incessant upgrade treadmill. I've been using GNUCASH instead. It doesn't have all of the features that Quicken had (e.g. downloading transactions from your financial institutions) but it is free and stable. You have to get used to double entry bookkeeping, but that is a minor obstacle to overcome.

Intuit makes most of their money using regulatory capture [https://en.wikipedia.org/wiki/Regulatory_capture](https://en.wikipedia.org/wiki/Regulatory_capture) instead of delighting customers. For example, they collude with the Internal Revenue Service and the banking industry to prevent open source alternatives to electronic tax filing and the downloading of bank transactions under the guise of security.

Intuit needs to get back to producing products which are superior to open source alternatives at a nominal cost without using regulatory capture as a key aspect business model.

</comment><comment><USER4> Intuit has a basketball court and an entire building with random crap everywhere dedicated to "inspiring" employees. It's a symbol of Silicon Valley excess better than anything put on television by HBO. Especially since they are neighbours to Google and constantly in a battle to outbid them to be the coolest company to work for.

I think it's safe to say there's some bloat that could be cut from Intuit.</comment>


Is eBook publishing pricing killing libraries? - <AUTHOR> https://twitter.com/kidsilkhaze/status/1115293506946387968 <comment><USER2> I agree. Ebooks permit and encourage an obscenity in publishing, a perversion of the first sale doctrine, with on-going price gouging. The experience is not better, and isn't worth it.</comment>