# Video: Scientific Method

Which of the following statements most correctly defines a scientific test? [A] A test is the process of scientists comparing their hypotheses to those made by other scientists. [B] A test is a model of some phenomenon. [C] A test is a method of showing that a hypothesis is true. [D] A test is the comparing of measurements of a phenomenon to predictions made by a hypothesis.

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### Video Transcript

Which of the following statements most correctly defines a scientific test?

Now we’ve been given four statements here. So let’s go through them one by one and see which one sounds correct: number 1) a test is the process of scientists comparing their hypotheses to those made by other scientists.

So let’s think through this one carefully: what benefit would that be to scientists comparing their hypotheses to those made by others? Well, all it would serve to do is to show how other scientists think. But that doesn’t necessarily mean that they’re correct. So if we as scientists made a hypothesis and then compared this hypothesis with those made by other scientists, then all we’d be able to tell is if we had the same level of thinking as other scientists. And this isn’t necessarily beneficial because of course it is possible that all the other scientists have hypotheses that actually aren’t correct and the one that we’ve devised is closer to the truth. But if we just compare hypotheses, then there’s no way of finding this out. Moreover, this is not even close to the definition of a scientific test.

So this one is not the one we’re looking for and hence we can move on to number 2) a test is a model of some phenomenon. Well, this isn’t quite right either. A test is meant to check for something to test for something just as we would expect. But when we model a phenomenon that’s a scientific or mathematical model, not a scientific test. So this one is not the right answer either.

And so we can happily move on to number 3) a test is a method of showing that a hypothesis is true. Now, this statement is rather dangerous and the reason for this is twofold. Firstly, we can never ever prove that a hypothesis is true. All we can confidently say is that when we conduct an experiment all we can ever say with confidence is that if our results go against our hypothesis, then our hypothesis is false. But if our experimental results agree with the predictions made by the hypothesis, then that still doesn’t prove that the hypothesis is true. That only proves that the experimental results we got seem to show that our hypothesis is along the right lines. However, it’s still possible that we could get the right results just by chance. And in fact, the hypothesis is completely wrong. But we just got lucky. So that’s the first reason why we can never say that a test is a method of showing that our hypothesis is true.

The second reason is that a test should never aim to show that the hypothesis is true because at that point we’ve already assumed that the hypothesis is true and we’re looking for experimental results to back us up. This is never how science should work. We should always be open minded. Regardless of how correct we think we are with our hypothesis, we should never seek to find results that back our claim. This is called cognitive bias, which is when we assume something is true and look for something to back us up. Instead experiments conducted should always be with an open mind like we said earlier. And they should be done as fairly as possible so that the results could either back our hypothesis or show that it’s false.

And remember once again we can never show that a hypothesis is true we can only say with certainty that the results that we have seem to back our hypothesis. But we could have just gotten lucky. However, the more and more experiments we do and the more and more results we get that seem to agree with our hypothesis, the more likely it is that our hypothesis is along the right lines, whereas one negative result — one result that goes against the hypothesis and it falls apart completely.

So anyway, this reason is not our final answer either, which means it’s very likely that four is the correct one. However, let’s read it just to be sure. So number 4) a test is the comparing of measurements of a phenomenon to predictions made by a hypothesis. And yes, this definitely sounds like the correct definition of a scientific test. The whole point is to come up with a hypothesis that explains let’s say a phenomenon and then make predictions based on that hypothesis that we can test using experiment. Then, we actually conduct those experiments and compare the results from those experiments to the hypothesis’s predictions.

If the predictions made by the hypothesis match the results that we get from the experiment, then we’ve got solid evidence to suggest that the hypothesis might be along the right lines. However, if the experimental results disagree with the predictions made by the hypothesis, then the hypothesis is false. It’s incorrect. And the whole point of a scientific test is to compare the measurements from the experiment with the predictions made by the hypothesis. So this is the answer we’re looking for.

And so our final answer is that a test is the comparing of measurements of a phenomenon to predictions made by a hypothesis.