Scientific method example: Failure to toast
Let's build some intuition for the scientific method by applying its steps to a practical problem from everyday life.
1. Make an observation.
Let's suppose that you get two slices of bread, put them into the toaster, and press the button. However, your bread does not toast.
- Observation: the toaster won't toast.
2. Ask a question.
Why didn't my bread get toasted?
- Question: Why won't my toaster toast?
3. Propose a hypothesis.
A
hypothesis is a potential answer to the question, one that can somehow be tested. For example, our hypothesis in this case could be that the toast didn't toast because the electrical outlet is broken.
- Hypothesis: Maybe the outlet is broken.
This hypothesis is not necessarily the right explanation. Instead, it's a possible explanation that we can test to see if it is likely correct, or if we need to make a new hypothesis.
[Can any explanation count as a hypothesis?]
[Is a hypothesis a theory?]
4. Make predictions.
A prediction is an outcome we'd expect to see if the hypothesis is correct. In this case, we might predict that if the electrical outlet is broken, then plugging the toaster into a different outlet should fix the problem.
- Prediction: If I plug the toaster into a different outlet, then it will toast the bread.
5. Test the predictions.
To test the hypothesis, we need to make an observation or perform an experiment associated with the prediction. For instance, in this case, we would plug the toaster into a different outlet and see if it toasts.
- Test of prediction: Plug the toaster into a different outlet and try again.
- If the toaster does toast, then the hypothesis is supported—likely correct.
- If the toaster doesn't toast, then the hypothesis is not supported—likely wrong.
The results of a test may either support or contradict—oppose—a hypothesis. Results that support a hypothesis can't conclusively prove that it's correct, but they do mean it's likely to be correct. On the other hand, if results contradict a hypothesis, that hypothesis is probably not correct. Unless there was a flaw in the test—a possibility we should always consider—a contradictory result means that we can discard the hypothesis and look for a new one.
[More about hypotheses, proof, and disproof]
6. Iterate.
The last step of the scientific method is to reflect on our results and use them to guide our next steps.
[IMG alt="And the result is:
Left panel: My bread toasts! Hypothesis is supported.
Right panel: My bread still won't toast. Hypothesis is not supported.
6. Iteration time!
Left panel (in case of hypothesis being supported): But what is actually wrong with the outlet?
Right panel (in case of hypothesis not being supported): Hmm...maybe there is a broken wire in the toaster."]
https://cdn.kastatic.org/ka-perseus-images/f48c1e8ff077decb6d8adafa35d665d7df815b87.png[/IMG]
And the result is:
Left panel: My bread toasts! Hypothesis is supported. Right panel: My bread still won't toast. Hypothesis is not supported.
- Iteration time!
Left panel (in case of hypothesis being supported): But what is actually wrong with the outlet? Right panel (in case of hypothesis not being supported): Hmm...maybe there is a broken wire in the toaster.
- If the hypothesis was supported, we might do additional tests to confirm it, or revise it to be more specific. For instance, we might investigate why the outlet is broken.