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  • Why are some kids sad?

  • What makes the wind blow?

  • How do birds fly?

  • Our world is full of curious phenomena.

  • To find answers or solve problems,

  • we can use a process, which was first acknowledged

  • by the scientist and philosopher

  • Ibn al-Haytham, in the 11th century.

  • Also known as Alhazen,

  • he is considered to be the father of optics

  • - and the scientific method.

  • There are six steps to it:

  • 1.Observe and Ask Questions

  • 2.Research

  • 3.Formulate a Hypothesis

  • 4.Test your hypothesis

  • 5.Conclude

  • 6.Share Results

  • The goal of the scientific method is find out the truth.

  • Let's try.

  • Step 1: Observe and Question

  • Observation helps us formulate challenging questions

  • that you will be able to test.

  • A good question converts the natural sense of wonder

  • into a focused line of investigation.

  • When is the best time to drive to school?

  • Which food is my dog's favorite?

  • For example

  • If you observe that women smile more often than men,

  • you might ask: why do women smile more often?

  • Step 2: Research

  • Find out if other people have asked the same

  • or similar questions.

  • If you research online, use search terms like

  • study ...”, “research ...” ormeta-analysis ...”

  • - which is a summary of research for a specific topic.

  • Read as much about your particular subject

  • to see what you can find out about.

  • For example, Research happiness based on gender

  • or study the science of smiling

  • in different cultural contexts.

  • Step 3: Formulate a Hypothesis

  • A hypothesis is a theory that you can test

  • to see if your prediction is right or wrong.

  • From your observation,

  • you have noticed that woman smile more often

  • and that people who are smiling seem to be happy.

  • From your research

  • you know that there are different types of smiles,

  • shy, genuine and false.

  • In one paper you read that baby girls

  • smile more often than baby boys.

  • Here is a hypothesis:

  • Women smile more than men

  • because they are happier than men.

  • Step 4: Test Your Hypothesis

  • When you test your hypothesis,

  • you want to make sure to do this in a fair way

  • and that the conditions are constant.

  • For this hypothesis, we can design a test

  • where an interviewer talks with a set of men

  • and women for 5 minutes each,

  • counts how many times they smile,

  • and then asks each one to rate their level of happiness.

  • To get a good sample of the population,

  • we invite 300 women and 300 men.

  • Seems like a good test, right?

  • But wait, what if the interviewer is a woman,

  • and men tend to smile more at women?

  • Or vice versa?

  • Or what if the topic discussed

  • is one that interest women more than men?

  • And what if people aren't reliable reporters

  • of their actual level of happiness?

  • So clearly, we would need to be much more careful.

  • Step 5: Analyze and Conclude

  • Let's assume that you designed a very careful experiment,

  • controlling for as many variables as possible.

  • Now you can analyze the data

  • to see if your hypothesis is correct, or incorrect.

  • Depending on your findings,

  • you may want to change your hypothesis

  • or change the design of your testing.

  • Perhaps you have discovered an even more interesting question.

  • This stage of the scientific method

  • can be repeated as many times as necessary

  • until you find just the right hypothesis

  • and test method to find accurate results.

  • Step 6: Share the Results

  • When you are satisfied that you have

  • proven or disproven something important,

  • report your results.

  • In science, it is important to detail your methods

  • so that your peers can review your work

  • - which is a critical step to getting published.

  • If your results are solid,

  • your experiment can be repeated by other scientists.

  • Such reproducibility is a sign of good scientific work.

  • But failed results can also be interesting

  • - an incorrect prediction could prove to be

  • important and should always be reported.

  • To make sure you get it completely right,

  • here are 3 more things you can check before you publish:

  • A) Any scientific theory is falsifiable

  • Real scientists know that there is no such thing as a scientific proof.

  • In other words, you can never prove your theory to be 100% right.

  • All you can do is find A LOT of supporting evidence

  • that it could be correct.

  • Here is one example:

  • Say that someone sayshamsters CAN fly,”.

  • We cannot prove that this as false.

  • Yes, we have never seen a hamster fly,

  • but we can't test all possible conditions

  • or look in all possible places on the planet

  • to know that ALL hamsters NEVER fly.

  • Maybe a space hamster does?

  • So while we can often prove that a phenomenon exists,

  • it's much harder to prove the nonexistence of something.

  • If your theory can't possibly be proven wrong,

  • then it's not falsifiable and hence, not scientific.

  • B) Correlation is not Causation

  • When you analyze your results,

  • it is important to separate between two possible reasons:

  • correlation or causation.

  • Let's you hear that towns that have more churches

  • also have more bars.

  • Could it be that religion makes people want to drink?

  • Or that drinking helps people to find God?

  • If you add more facts, such as

  • larger towns have both more bars and more churches,”

  • you can see that a larger population

  • is a more likely cause of higher numbers of bars

  • AND churches.

  • There is probably a correlation, but no causation.

  • If we compare men with women

  • and would conclude that woman smile more and are more happy,

  • then this still doesn't mean that its happiness that makes them smile.

  • Maybe they just eat more chocolate and cookies,

  • which makes them both: happy and smile a lot.

  • C) Avoid Selective Windowing

  • When you publish you got to show ALL relevant facts.

  • Colgate once ran a advertising campaign

  • claiming that “80% of dentists recommend Colgate”.

  • What they didn't tell us

  • is that when they asked dentists

  • to select their preferred toothpaste,

  • Colgate was just one of many other brands

  • they also also recommended.

  • Colgate was later sued and forced

  • to take down their misleading ads.

  • The purpose of science is always to find out

  • the truth and nothing but the truth.

  • To use science to mislead us is wrong

  • and terrible business practice.

  • Lets do a last example together.

  • I have two coins.

  • One is bigger.

  • Why?

  • The small coin says 1 Cent,

  • the bigger one says 5.

  • Aha!

  • Small coins are worth less money.

  • Bigger coins are worth more money.

  • I pull some more coins from my pocket.

  • 2 more Pennies, 1 more Nickel,

  • and a Quarter Dollar, which is 25 Cents.

  • Great, my hypothesis seems true.

  • But wait, is the quarter worth more because it is bigger?

  • So is that a correlation or a causation?

  • Hmmmm

  • My sample size is pretty small.

  • I don't think I am ready to report my results.

  • Can you help out?

  • Please apply the Scientific Method

  • to study you local currency.

  • Maybe you have a hypothesis

  • that we can test until we get solid,

  • repeatable results to report.

  • Please publish your findings in the comments below!

Why are some kids sad?

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A2 初級

科学的方法。ステップ、例、ヒント、演習 (The Scientific Method: Steps, Examples, Tips, and Exercise)

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    Summer に公開 2021 年 01 月 14 日
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