Building and Testing a Good Hypothesis

credit: Chronicle

A hypothesis is a tentative claim about the relationship between two or more variables. Basically, it's what you're expecting to happen in a study. If/then statements are the most common form of hypothesis writing. What may happen because of the possible outcome of this statement is explained in this statement (then). You could also use the word "may" in the sentence. However, a hypothesis cannot always be proven to be true based on analysis of the results. That is why a test or an experiment is performed in order to prove the validity of the hypothesis.

Hypothesis vs Theory

Scientists construct hypotheses before conducting any relevant research, aside from a basic background review. You ask a question, do some research, and then form a hypothesis. Then, you test your hypothesis. 

On the contrary, a theory is an attempt to explain something that has already been supported by data. Because of the experimentation and the data the theory is based on, it is thought to be more likely to be true than a hypothesis. In science however, both hypothesis and theory is used side by side.

Scientific Method on Hypothesis

Hypothesis can be considered as the foundation to scientific method because hypothesis is built based on guess despite the fact that the guess can be correct or not. To test a hypothesis we can follow the scientific method according to the following steps.

• Making questions
• Background research
• Building up a hypothesis
• Perform the experiment
• Gather data
• Result analysis
• Conclusions

Now let's try to build up a hypothesis on one of the most famous beliefs in the early centuries and test it according to the scientific method. The belief is non other than the Spontaneous Generation. In the middle ages, Greeks and romans believed that complex living organisms can come to life out of nothing but non-living things. They used to believe that maggots are born out of rotten meat, mice are born from decaying pieces of cloth and so on. Now, let us try to build a hypothesis around that and test it in order to prove it wrong.

The first thing that we have to do is make questions. Can living things really come to existence purely out of non-living matters? If so, how? What are the creatures that undergo spontaneous generation?

Now, let's do a little background research. As the Nile River flooded Egypt every spring, nutrient-rich soil was left behind that allowed people to grow food for that year. However, along with the muddy soil, a large number of frogs appeared that were not present during the dry season. In conclusion based on this, frogs were born out of muddy soil, which was clear to everyone at the time.

Let us now move on to build a hypothesis. Let's take a piece of rotten meat for instance. 

(P1) If a piece of meat is left to be rotting, then maggots can be born inside it.

(P1) A piece of meat is left to be rotting.

-------------------------------------------------------------------

(C) Therefore, maggots can be born inside it.

We all can see that the above argument is invalid. However, let's move on to the next step, which is testing the hypothesis. Let's take two jars containing two equally similar pieces of meat, with one inside of them each. Close one jar not letting air inside it and keep the other one open. Let us gather some data. In a few hours, you will be able to see flies inside the open jar and feed on the rotten meat and you will also be able to see flies around the closed jar as well. In a matter of a few days, you will able to see tiny maggots come out of the open jar and nothing happening inside the closed jar. 

Let's move on to analyze the results. Flies were able to feed on one of the pieces of meat because one was left in an open jar and the flies were unable to even go near the other piece of meat because it was inside a perfectly sealed jar. Therefore, flies were able to feed on the meat inside the open jar and lay eggs on it. And eventually, eggs hatched and maggots came out. But inside the sealed jar, what you were able to see was just a rotten piece of meat.

Finally, let's come to a conclusion. One jar was sealed and the other one was open. The piece of meat in the open jar was full of maggots because flies could feed on it and lay eggs on it as well. On the other hand, flies could not feed on the piece of meat inside the sealed jar and they were unable to lay eggs on it. Therefore, meat cannot give birth to maggots. Therefore as a whole, we can prove that the above hypothesis is wrong and the Spontaneous Generation is also wrong.