Practice Using the Scientific Method with Louis Pasteur
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Science comes from the Latin root scio, meaning knowledge. Essentially, the study of science is a method of reasoning to learn more about the world around us rather than a collection of discrete facts or even principles, theories and laws.
Experimentation is how science gets done, but many “experiments” I see online and even in some textbooks are really just demonstrations. Demonstration activities can be important for illustrating scientific concepts and principles, but they are not how scientists learn about their world.
Since the scientific method is at the heart of how scientists conduct research, I think it is important that students learn to set up their own experiments and report on the results using the scientific method.
Louis Pasteur’s commitment to the scientific method solved many of the pressing problems of his day. (And he was considered an “average” student in school!) Then we will take a closer look at what the scientific method is and set up a basic experiment.
Louis Pasteur
Louis Pasteur was described as an “average” student, but he went on to do amazing work as a scientist. His commitment to rigorous experimentation led him to develop the process of pasteurization, helped him save the silkworm industry, and gave us vaccines against such deadly diseases as cholera, tuberculosis, anthrax and even rabies.
His use of the scientific method coupled with his scientific successes also led to the formalization and widespread usage of the scientific method itself.
The development of pasteurization
Seeking to help solve problems with the manufacture of alcoholic drinks, Pasteur soon was able to prove that bacteria were responsible for souring beer, wine, and even milk.
He did not invent the germ theory, but through experimentation, he was able to further develop it. He was able to demonstrate that heating a liquid killed bacteria and when it was cooled, it would need to be re-infected for bacteria to begin to grow again.

This experimentation led to the widespread acceptance of the germ theory and also led to industries adopting pasteurization as a method of preserving food around the world.
Saving the silk worm industry
In 1865, Pasteur reluctantly responded to the invitation of an old friend to come to the south of France and research a disease that was devastating the local silkworm industry. He and his students studied the problem for some time and Pasteur finally thought he figured it out.
Adult moths with globules passed the disease on to the eggs. Breeders would simply have to sort the females and destroy the eggs of any that had these globules. But he had to wait for the eggs to hatch in order to prove his hypothesis.
The results were devastating. Hatchlings he thought should have had the disease turned out healthy. Others that shouldn’t have it were dying. What was going on?
They were eventually able to demonstrate there were actually two diseases attacking the silk worms, not one.
He was also able to demonstrate the primary disease he was researching was being passed from worm to worm via droppings on the leaves and the second was passed through the intestines. This information led to better practices that allowed the silkworm industry in southern France to recover and prosper.
Development of vital vaccines
Pasteur’s interest in vaccination was the result of an accident. After mistakenly exposing a flock of chickens to a weakened strain of chicken cholera in 1879, he was able to demonstrate that they became immune to the disease.
This led to further research and the development of vaccines to fight anthrax, cholera, tuberculosis and smallpox. These successes eventually led him to tackle the problem of rabies.
Rabies and Vaccines
Rabies was prevalent in Europe in his day. The only efforts at control involved attempts to control the populations of stray dogs and other animals around the city, but it was not enough. There was no cure and it led to a slow, painful death.
In 1885, a rabid dog attacked a group of children. Joseph Meister, a nine-year-old shepherd boy, stepped in front of the group of children and fought the dog to protect the others. His town considered him a doomed hero.
Success with Rabies
They had heard about Louis Pasteur’s work and asked if he might look at the boy. Pasteur administered the first round of his vaccination on July 6, 1885. The boy did not contract rabies and Pasteur achieved near instant international fame.
People from all over the world came to see him in France to receive vaccinations for rabies, including an entire group from Russia. Because of the length of travel, some were already exhibiting symptoms by the time they arrived. He treated them with a modified protocol and all but three survived.
People from around the world raised money to fund the Pasteur Institute in Paris in his honor.
Pasteur and the scientific method
Louis Pasteur was not the first to use the scientific method. Inductive reasoning was first promoted as a part of science by Roger Bacon (12-14 – 1284).
Its roots trace back even further. His systematic use of the scientific method and incredible discoveries helped formalize the method. Ultimately, making it the method to use among scientists.
The scientific method forms the basis of how science “gets done” now. Scientists observe, measure and test using the scientific method.
Learning the Scientific Method
Experimentation is at the core of science, but not science education. Have you noticed how many science “experiments” online and even in textbooks are really just demonstrations and do not employ the scientific method at all?
Demonstration vs. Experiment
A demonstration is an activity that demonstrates a scientific concept or principle. Demonstrations are useful for teaching scientific principles. They illustrate concepts and are very hands-on, drawing children in and keeping their interest.
Dropping a Mentos into a bottle of Coke is a dramatic introduction to chemistry, making the lesson more memorable. Demonstrations are an important part of teaching science, but they should not constitute the whole of the science curriculum.
Experiments are different
An experiment requires a control group and several experimental groups to test variables. Science happens through experimentation. It’s important to teach children the scientific method and help them develop their own experiments.
It takes more time and a greater commitment than a simple demonstration, but it teaches children how to reason scientifically. That’s why my goal is to have the children set up one experiment per semester, complete with a lab report.
What is the scientific method?
The scientific method is simply a process of experimentation. It allows a scientist to test a hypothesis and publish the results in a format that allows other scientists to repeat the experiments.
Repeated experiments yield more reliable results. Not every scientist goes through the steps in the exact same way, but the same general principles guide all good experiments.

Scientists include information about experimental design so that other scientists can replicate it in their publications.
Different scientists approach the same experiments different ways. This helps validate their results. It makes sure that what they think is happening really is what is happening.
Experiment
You can help your child design an experiment to test anything (observable) that they would like. The only limiting factor is that you must have access to the resources to complete.
When first starting out, however, it is very helpful to have an experiment to refer to. This helps teach the structure. Once they have been through the process a few times, they should be ready to begin designing their own experiments.
My children had a great time setting up experiments related to those “demonstrations” you find on YouTube. I put demonstrations in quotes because not one of them worked.
Would you like a copy of the experiment that my children set up?
You can grab this experiment and much more in the Science Celebration Yearbook 2017


A fabulous study! There are so many great ways to teach our kids at home. I’ve created some of my own curricula myself, but sought out things like this from others when I wasn’t in my areas of expertise.
I was just talking about this with another mom. We don’t need to put so much pressure on us to be experts in every area.