[talkingtab]

I am slowly becoming convinced that studies are in fact cargo-cultism. And there are many, many studies that confirm this.

But about causality. Long ago (old cars) I had a friend who told me that most mornings his car would not start until he opened the hood and wrapped some wires with tape (off with the old tape on with the new). Then the car would start. Every now and then it would take two wraps. Hmmm.

After he demonstrated this, I decided to try to help. I followed the wires that were wrapped. Two of them. To my surprise they were not connected at either end. This was insane, and yet his study - and my own observation - demonstrated that wrapping these two wires which were completely disconnected caused his car to start. Now there is causality for you.

Except that if you have a more complex model of cars, there is a sane explanation. Again this is an old car with a carburetor. In case you don't know this is a little bowl of gas it that provides a combustible mix of air and gas. If there is too much gas then your car won't work. The mix is controlled by a little float that controls the level of gas in the little bowl. Toilet bowls work on the same principle.

If your float is bad (or other issues) your car engine would get too much gas - be "flooded" and you have to wait until much of it evaporates. So if you flood your car engine, go and wrap some wires, it may be that your car will start right up.

So I rebuilt the carburetor and my friend never had that problem again.

The moral of the story is that I had better "model" of how cars work. But in the back of my mind I am aware that my model may be or have been just as deficient. Did you know that we are bombarded from space by an unknown type of neutrino that stops electricity from working unless there is a little pool of some liquid nearby or it is Thursday. I am going to do a study of this.

There are very good reasons to understand how frail our ability to understand causality is. And we are talking simple things here. The scientific method is about EXPERIMENTS. Yes, I did that in bold. Doing things. We have deeply complex situations we need to understand and in my opinion, studies do not help.

[gwern]

> After he demonstrated this, I decided to try to help. I followed the wires that were wrapped. Two of them. To my surprise they were not connected at either end. This was insane, and yet his study - and my own observation - demonstrated that wrapping these two wires which were completely disconnected caused his car to start. Now there is causality for you.

You didn't show causality, though. You never randomized anything. His study and your observation was purely observational. At no point did you open the hood, get ready to wrap the wires, and flip a coin to decide whether to wrap the wires or do a placebo wrapping somewhere else.

Had you done that, you would have found, per your ultimate explanation, that the wrapping made no causal difference: you did the procedure, and either way, the car turned on. Hence, there is no causality for you.

[bwfan123]

imo, The idea of a cause is a logical concept of containment when used in theories. A causes B means the phenomena represented by A implies the phenomena represented by B. So, causation is a device of our symbolization and understanding of the world rather than anything fundamentally out there. this is of course a controversial view.

Causality eventually demands a "theory" for full explanatory power and understanding. Theories have premises, involve inference, and have predictions. Otherwise, we get ad-hoc models of phenomena via observations which is a great start, but ends up as an oversimplification. X causes Y but, what caused X or why did X cause Y and not Z ? models represent phenomena while theories explain them. we start with models, and then our curiosity eventually leads to a theory. refer [1] for a great read from a physicist turned quant.

[1] https://www.amazon.com/Models-Behaving-Badly-Confusing-Illus...

[yccs27]

If I understand it correctly, they randomly decided to try starting the car immediately or to go wrap the wires first. This absolutely demonstrates a causality, they just didn't cleanly separate the different factors which changed.

Your comparison to placebo is very apt: Giving medication to a patient (vs not giving anything) causes them to get better, but it might be the "giving a pill" part instead of the "ingesting medication" part that matters.

[swores]

It doesn't show causality because their decision of when to do it wasn't random (so maybe when in the mood to go straight to wrapping wires they were also in the mood to turn the key slightly more firmly, or...), and also because there's no way of knowing if wrapping the wires was in any way relevant - maybe the vehicle actually just needed X minutes between unlocking and starting, and wrapping wires was a way to spend that time without using a timer, or maybe... who knows what other maybes!

And sure enough, their story concludes with discovering that there was no causality from the wire wrapping at all. It was just about killing time.

[schneems]

I liken this to the experience of playing an old school fighting game in the era before the internet. You would be mashing buttons when suddenly your character would do a power move. Then spend the rest of the day trying to figure out how to reproduce it.

If you could reproduce it, it would usually be intermittent. Eventually you would learn “when I X then my character will Y, but only sometimes.

This is due to the real command being a subset or being a slight variation of what you thought was correct that you accidentally do sometimes.

Even when it’s ephemeral and seemingly random I still find these things valuable. It’s better to be able to reproduce it sometime instead of never. Answering the question “is doing this better than random?” (P95) can help you throw away a bad hypothesis. Most people don’t realize that when they are providing evidence for causality they are competing with random. If they had instead done jumping jacks or said a prayer to the engine gods X times, then the correlation between the wires and the engine might suddenly seem much weaker.

Once you have one hypothesis you can test it against others and I believe that’s powerful. Provided it’s done systemically and with at least a mild understanding of probability and error. Also a hypothesis without a theory first scientific. Why did your friend wrap the wires to begin with?

It’s okay to act in random until we find some effect, but then we also need to take the time to roll back (as you did) to ask “WHY did this happen?” In which case you can begin the process with a fresh hypothesis.

I feel when we are taught the scientific method in elementary school it doesn’t stick for most of us, even engineers. Especially non-engineer folks. It seems at first blush like some truisms strung together, but that simplicity hides very powerful capabilities and subtle edge cases.

[shadowgovt]

I think the most fascinating thing about the practice of science (and this is one of those things I wish I'd realized sooner when learning physics) is that experimental evidence often outstrips theory.

There are all manner of observable, reproducible behaviors in nature that we barely have an explanation of. Those things remain observable and reproducible whether we can tell a tidy story about why they happen.

In a very meaningful sense, the local healer applying poultices formulated from generations of experimentation is using science much as the medical doctor is (assuming, of course, they're taking notes, passing on the discoveries, and the results are reproducible). The doctor having tied their results to the "germ theory of medicine" vs. the local healer having tied theirs to "the Earth Mother's energies impregnate the wound" is an irrelevant distinction until (and unless) a need comes along to unify the theory to some other observable outcomes.

[atombender]

That's true for simple things. You don't need to know what the pharmacological mechanism of COX inhibitors is in order to prescribe Advil for a headache. But if you're a scientist trying to make a better Advil you probably need to know how it works.

Doctors routinely prescribe medications that have no randomized clinical trials supporting their use. In those cases, clinical experience replaces trial data; they "know" the drugs work because all the patients have effectively been trial subject over a span of decades.

[Retric]

> The scientific method is about EXPERIMENTS

IMO the model of that story is the S at the end of experiments is more than just repeating the same things. Fixing the carburetor was the second and vastly more informative experiment, but your friend could have tried various alternatives to doing exactly what he was doing which would then uncover the time component.

Science digs into problems, so the most important part of meta analysis, which is often ignored, is asking if the question even makes sense in a generic context. Just as crucial is narrowing down the effect size which may be dwarfed by random noise in some experiments etc.

[ramon156]

Doesn't this heavily apply to building software as well? e.g. instead of spray and pray development we should get a better understanding of the model we're working with.

If my parser gets null's when it should be non-null then I first need to find where they could potentially even come from, aka get a better understanding of the model I'm working with.