# Video: Definition of Scientific Measurement

Which of the following statements most correctly defines a scientific measurement? [A] A measurement is a method of showing that a hypothesis is true. [B] A measurement is the act of noticing this phenomenon seems to occur. [C] A measurement is a prediction about the observation of some phenomenon. [D] A measurement is the process of determining the value of a quantity in an observation.

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### Video Transcript

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

Okay, so, in this question, we’ve been given four different options that are possible descriptions of a scientific measurement. So, let’s go through them one by one and see which one is correct, starting with option A. A measurement is a method of showing that a hypothesis is true. Now, this statement is very problematic. But let’s first realize that the word hypothesis means a possible explanation offered by a scientist for some event or some phenomenon happening in the universe. And when it’s a hypothesis, it’s basically just an educated guess.

Now, that hypothesis needs to be tested in order to see whether or not it’s a good description of what’s happening in the universe. And that’s what this statement is alluding to. This statement is saying that a measurement is a method of showing that our hypothesis is true. However, one can never show a hypothesis to be true. Any experiments that we conduct will either agree or disagree with the hypothesis.

And if an experiment disagrees with a hypothesis, then immediately we can say that the hypothesis is false. However, if all the experiments that we conduct agree with the hypothesis, then we can only say that the hypothesis is a good description of what’s happening in the universe. Because there might still be an experiment that we haven’t yet conducted that shows our hypothesis to be false. And for this reason, option A is not the answer to our question.

Moving on to option B then. A measurement is the act of noticing that some phenomenon seems to occur. Where the word phenomenon basically just means an interesting event, something that happens in the universe that a scientist will try and explain. And option B is saying that a measurement is the act of noticing this phenomenon. Well, the act of noticing that some phenomenon seems to occur is actually an observation, not a measurement. A measurement is a little bit more than that. And we’ll come back to that when we look at the next two options. But for now, we can say that option B is referring to an observation, not a measurement. And therefore, it’s not the answer to our question.

Moving on to option C then. A measurement is a prediction about the observation of some phenomenon. Now, when a scientist comes up with a hypothesis, a possible explanation as to why something that they observed occurs in the first place. Then, they develop that hypothesis, building a framework around it, a mathematical framework most commonly. And that mathematical framework is known as a scientific model. In other words, that scientific model is basically a more thorough description of what the hypothesis is trying to say. And that scientific model will have some predictions as to other phenomena that can occur, which the scientist can then test to see if they occur.

And if they do occur, then that’s good evidence that the hypothesis of the scientist is along the right lines. And if those predicted phenomena don’t occur, then it’s good evidence that the hypothesis of the scientist is incorrect. But the point is that a scientific model can make predictions about the observations of some phenomenon. But that in itself is known as a prediction, not as a measurement. And hence, option C is not the answer that we’re looking for.

So, moving swiftly on to option D. A measurement is the process of determining the value of a quantity in an observation. And this is exactly what a measurement is. A measurement is a little bit more than the description seen in option B, which was the description of an observation. Which is simply noticing that something is happening. Because a measurement is made when the value of some quantity is found.

So, for example, if we’re conducting an experiment where we take a ball and roll it along the ground, then we can make a measurement of the distance traveled by the ball. And the measurement itself will be made when we determine the value, let’s say 0.5 meters of the quantity, which is the distance traveled by the ball when we’re making an observation. And so, at this point we’ve found the answer to our question. A measurement is the process of determining the value of a quantity in an observation.