(I once posted this question on academia.stackexchange, but it was deemed to be off topic there. I hope it would be more on-topic here)
I would like to introduce the basics of the scientific method to an audience unfamiliar with the real meaning of it, without making it hard to understand.
As the suspected knowledge level of the intended audience is of the type which commonly thinks that to "prove something scientifically" is the same as "use modern technological gadgets to measure something, afterwards interpret the results as we wish", my major topic would be the selection of an experimental method and the importance of falsifiability. Wikipedia lists the "all swans are white" as an example for a falsifiable statement, but it is not practical enough. To prove that all swans are white would require to observe all the swans in the world. I'm searching of a simple example which uses the scientific method to determine the workings of an unknown system, starting by forming a good hypothesis.
A good example I found is the 2-4-6 game, culminating in the very catchy phrase "if you are equally good at explaining any outcome, you have zero knowledge". This would be one of the best examples to illustrate the most important part of the scientific method which a lot of people imagine incorrectly, it has just one flaw: for best effect it has to be interactive. And if I make it interactive, it has some non-negligible chance to fail, especially if done with a broader audience.
Is there any simple, non-interactive example to illustrate the problem underlying the 2-4-6 game? (for example, if we had taken this naive method to formulate our hypothesis, we would have failed)
I know, the above example is mostly used in the topic of fallacies, like the confirmation bias, but nevertheless it seems to me as a good method in grasping the most important aspects of the scientific method.
I've seen several good posts about the importance of falsifiability, some of them in this very community, but I did not yet see any example which is simple enough so that people unfamiliar with how scientists work, can also understand it. A good working example would be one, where we want to study a familiar concept, but by forgetting to take falsifiability into account, we arrive to an obviously wrong (and preferably humorous) conclusion.
(How I imagine such an example to work? My favorite example in a different topic is the egg-laying dog. A dog enters the room where we placed ten sausages and ten eggs, and when it leaves the room, we observe that the percentage of eggs relative to the sausages increased, so we conclude that the dog must have produced eggs. It's easy to spot the mistake in this example, because the image of a dog laying eggs is absurd. However, let's replace the example of the dog with an effective medicine against heart diseases where someone noticed that the chance of dying of cancer in the next ten years increased for those patients who were treated with it, so they declared the medicine to be carcinogenic even though it wasn't (people are not immortal, so if they didn't die in one disease, they died later in another one). In this case, many people will accept that it's carcinogenic without any second thought. This is why the example of the egg-laying dog can be so useful in illustrating the problem. Now, the egg-laying dog is not a good example to raise awareness for the importance of falsifiability, I presented it as a good and useful style for an effective example any laymen can understand)
I think it would be great to start with a theory that sounds very scientific, but is unfalsifiable, and therefore useless. Then we modify the theory to include an element that is falisfiable, and the theory becomes much more useful.
For example, we have a new kind of medicine, and it is very good for some people, but when other people take the medicine it kills them. Naturally, we want to know who would be killed by the medicine, and who would be helped by it.
A scientist has a theory. He believes there is a gene that he calls the "Spottiswood gene". Anyone who has the proper form of the Spottiswood gene will be safe, they can take the medicine freely. But some people have a broken version of the Spottiswood gene, and they die when then they take the medicine. Unfortunately the scientist has no way of detecting the Spottiswood gene, so he can't tell you whether you have the gene or not.
Now this theory sounds very scientific and it's got lots of scientific words in it, but it isn't very useful. The scientist doesn't know how to detect the gene, so he can't tell you whether you are going to live or whether you are going to die. He can't tell you whether it is safe to take the medicine. If you take the pill and you survive, then the scientist will say that you had the working version of the gene. If you take the pill and you die, the scientist will say that you have the broken version of the gene. But he cannot say what will happen to you until after it has already happened, so his theory is useless. He can explain anything, but he can't make predictions in advance.
Now another scientist has a different theory. She thinks that the medicine is related to eye color. She thinks anyone with blue eyes will die if they take the medicine, and she thinks that anyone with brown eyes will be okay. She's not sure why this happens, but she plans to do more research and find out. Even if she doesn't do any more research, her theory is much more useful than than the first scientist's theory. If she's right, then blue-eyed people will know that they should avoid the medicine, and brown eyed people will know that they can take the medicine safely. She has made predictions. She predicts that no brown eyed person will die after taking the medicine, and she predicts that no blue eyed person will live.
Of course, the second scientist might be wrong. But the interesting thing is that if she's wrong, then we can prove that she's wrong. She predicted that no one with brown eyes will die after taking the medicine, so if lots of people with brown eyes die, then we will know that she's wrong.
If her theory is wrong, then we should be able to prove that it's wrong. And then if the results don't prove that she's wrong, we accept that she's probably right. That's called falsifiability.
But the first scientist doesn't have falsifiability. We know that even If he's wrong, we'll never be able to prove it - and that means we'll never know if he's wrong or right. More importantly, even he is right, his theory still wouldn't do anybody any good.
The first theory is falsifiable as long as you're willing to let enough people die. Collect blood samples from everyone before they take the medecine. Sequence their full exome and put it on file.
once you have a few thousand dead and a few thousand survivors you should be able to narrow candidates down to a few dozen genes.
Make predictions about who will die out of the next few hundred who take the pill, bam.
Turns out it's an eye color gene having some weird effect on a vital pathway that the drug is linked to.
Alternatively if it's not genetic at all, ... (read more)