Video Transcript
Which of the following statements
most correctly describes the purpose of performing an experiment? Now we’ve been given four
statements here. So let’s go to them one by one and
see which one is correct. Number one, an experiment is
performed to discover new phenomena.
So let’s think through this
one. Is the purpose of an experiment
really to discover new phenomena? Well, sometimes when we conduct an
experiment, we can discover new phenomena. Something unexpected happens if
say, for example, the scientist conducting the experiment does something wrong, or
if the experimental setup is not working properly, or just coincidentally something
different happens to what we expect.
And this may turn out to be a new
phenomenon. However, did the scientist actually
set up the experiment and conduct it to discover this new phenomenon? Well, no. They might have gotten lucky and
discovered something new, but that wasn’t the purpose of conducting the
experiment. So this one is not the answer to
our question.
Let’s move on to number two
then. An experiment is performed to
generate observations about a known phenomenon. Now this one seems a little bit
more like the answer. What it’s suggesting is that we
conduct an experiment in order to get to know a known phenomenon better. However, this statement is quite
vague. It just says something about
generating observations.
So yes, this is closer to the
correct answer, but it’s still too vague late for our liking. So this is not the answer we’re
looking for. Number three, an experiment is
performed to test a prediction. Now this is more like it. This is very specific. We conduct an experiment to test a
prediction. The whole idea is that we come up
with a hypothesis, an idea about what might be happening, in order to describe a
known phenomenon.
Then we use that hypothesis to come
up with predictions that we can test with an experiment. And the whole point of this
experiment is to test the predictions made by the hypothesis. And hence, an experiment is
specifically designed to test these predictions. And we can see why this statement
is better than number two, because number two, like we said earlier, was too
vague. It just talked about generating
observations which, you know, it’s not gonna for us.
We need to be very, very
specific. We’re designing this experiment to
test this prediction made by this hypothesis. This allows us to be more
systematic with our science. We don’t just wanna be hand wavy
and generate observations. We want to specifically test a
prediction made by a hypothesis. This way we can be systematic, as
we said, because we can test all of the predictions made by one hypothesis and then
move on to the next hypothesis.
In essence, it’s better for the
admin part of science, because then we can very thoroughly test hypothesis and their
predictions. So number three looks like the
correct answer to our question. But let’s just make sure that
number four is indeed incorrect. Number four says that an experiment
is performed to confirm a hypothesis. Now this statement is very, very
wrong and very dangerous. Why is that?
Well we can never ever ever confirm
a hypothesis, because this is how science works. We come up with hypothesis, and we
test it with experiment. If the experimental result
disagrees with the predictions made by the hypothesis, then immediately we know that
the hypothesis cannot be correct. But if the experimental results do
agree with the hypothesis, then all we can say is that we’ve got solid evidence for
the hypothesis being along the right lines.
However, we cannot confirm the
hypothesis because we may have just gotten lucky and got the right results. Or the hypothesis may have given a
correct prediction for the wrong reasons. Also the experiment that we conduct
should never be performed to confirm a hypothesis, because as we’ve already said we
cannot confirm a hypothesis, but also this statement suggests that the scientists
already believes the hypothesis to be true and they’re just looking for experimental
results to confirm it.
This sounds very much like
confirmation bias, which is when you assume something is true and then look for
results to back you up. And that’s not how science
works. We should always be
open-minded. So number four is not our correct
answer either. Now just to clarify this final
point as to why number four is not correct, let’s look at an example.
Let’s say we’ve got this hill, and
we’ve got a ball at the top of the hill or nearly at the top of the hill. Let’s say that we hypothesize that
the ball teleports from where it is now to the bottom of the hill and we hypothesize
that it takes 10 seconds to get there. So what we do is we conduct an
experiment. We place the ball at the start
position. And then we check where it is 10
seconds later. Well 10 seconds later, it does end
up being where we expected it to be.
So our experimental results agree
with what we predicted. But does that mean that our
hypothesis is confirmed? Well, no. This would be ludicrous. Like we said earlier, we just got
lucky. The hypothesis that the ball
teleports from the top of the hill to the bottom of the hill gave us the right
answer for the wrong reasons. In reality, it probably just rolled
down the hill and it took 10 seconds to do that.
However, for us to discover that
assuming we didn’t know that already, we would have to conduct further
experiments. We’d have to check five seconds
later where the ball was. And we’d realize that the ball was
somewhere halfway down the hill five seconds after we released it. And then we’d realize that it
probably doesn’t teleport. But then maybe it did teleport from
here to here. So maybe we need to revise our
hypothesis.
And so that’s the point. We can never confirm a
hypothesis. The only thing we can do is to
conduct multiple different experiments to test various predictions made by a
hypothesis. And the more and more evidence that
we gather that agrees with the predictions made by the hypothesis, the more and more
likely it is that the hypothesis is along the right lines.
But we can never 100 percent
confirm it. We can only get close. But anyway, getting back to our
question, our final answer is that an experiment is performed to test a
prediction.
