The scientific method It is a research method that characterizes the natural sciences since the 17th century. It is a rigorous process that allows describing situations, formulating and contrasting hypotheses.
To say that it is scientific means that its goal is to produce knowledge.
It is characterized by:
- Formulation of question or problem. From the observation, a problem or a question arises that wants to be solved. In turn, a hypothesis is formulated, which is a possible answer to the question posed. Deductive reasoning is used to formulate hypotheses.
- Issuance of conclusions. The scientific community is responsible for evaluating the results obtained through peer review, that is, other scientists from the same specialty evaluate the procedure and its results.
- systematic observation. It is an intentional and therefore selective perception. It is a record of what happens in the real world.
- Experimentation. It consists of the study of a phenomenon through its reproduction, usually under laboratory conditions, on repeated occasions and under controlled conditions. The experimentation is designed in such a way that it can confirm or refute the proposed hypothesis.
The scientific method can lead to theory development. Theories are statements that have been verified, at least partially. If a theory is verified as true at all times and places, it becomes law. Natural laws are permanent and immutable.
There are two fundamental pillars of the scientific method:
- reproducibility. It is the ability to repeat experiments. For this reason, scientific publications include all the data on the experiments carried out. If they do not provide the data that allows the same experiment to be repeated, it is not considered a scientific experiment.
- Refutability. Every hypothesis or scientific statement can be refuted. That is, you must at least be able to imagine an empirically testable statement that contradicts the original statement. For example, if I say, “all purple cats are female”, it is impossible to falsify, because violet cats cannot be observed. This example may seem ridiculous but similar claims are publicly held about entities that are also not observable, such as aliens.
Examples of scientific method
- Anthrax contagion
Robert Koch was a German physician who lived in the second half of the 19th and early 20th centuries.
When we talk about a scientist, his observations are not only of the world around him but also of the discoveries of other scientists. Thus, Koch starts from Casimir Davaine’s demonstration that the anthrax bacillus is transmitted directly between cows.
Another thing he observed was unexplained outbreaks of anthrax in places where there was no individual with anthrax.
- question or problem: Why is there contagion of anthrax when there is no individual to initiate the contagion?
- Hypothesis: The bacillus or a part of it survives outside a host (infected living thing).
- Experiment: Many times scientists must invent their own experimental methods, especially when approaching an area of knowledge that has not yet been explored. Koch developed his own methods for purifying the bacillus from blood samples and making cultures of it.
- Result of the discoveries: Bacilli cannot survive outside a host (hypothesis partially refuted). However, the bacilli create endospores that do survive outside a host and are capable of causing disease.
Koch’s investigations had multiple consequences in the scientific community. On the one hand, the discovery of the survival of pathogenic agents (that cause disease) outside organisms initiated the sterilization protocol for surgical instruments and other hospital elements.
But in addition, his methods used in the investigation of anthrax were later perfected for the study of tuberculosis and cholera. To this end, he developed staining and purification techniques, and bacterial growth media such as agar plates and Petri dishes. All of these methods are still in use today.
- Conclusions. Through his work based on the scientific method, he reached the following conclusions, which are still valid today and govern all bacteriological research:
- In case of illness, a microbe is present.
- The microbe can be taken from the host and grown independently (cultured).
- The disease can be produced by introducing a pure culture of the microbe into a healthy experimental host.
- The same microbe may be identified in the infected host.
- smallpox vaccine
Edward Jenner was a scientist who lived in England between the 17th and 19th centuries.
At that time smallpox was a dangerous disease for humans, killing 30% of those infected and leaving survivors scarred or blind.
However, smallpox in cattle was mild and could be spread from cow to human through sores located on the cow’s udders. Jenner discovered that many dairy workers maintained that if they had contracted cattle pox (which cured quickly) they would not get human smallpox.
- Observation: Belief of immunity obtained from the contagion of cattle pox. From this observation Jenner went on to the next step of the scientific method, holding the hypothesis that this belief was true and developing the necessary experiments to prove or refute it.
- Hypothesis: Contagion of cattle pox gives immunity to human smallpox.
- Experiment: The experiments that Jenner performed would not be accepted today, since they were performed on humans. Although at that time there was no other way to test the hypothesis, experimenting on a child today would be completely inadmissible anyway. Jenner took cowpox sore material from the hand of an infected milkmaid and applied it to the arm of a boy, the son of her gardener. The boy was ill for several days but then fully recovered. Jenner later took material from a smallpox sore and applied it to the same boy’s arm. However, the child did not contract the disease. After this first test, Jenner repeated the experiment with other humans and later published his findings.
- Conclusions: confirmed hypothesis. Therefore (deductive method) infecting a person with cowpox protects against a smallpox infection. Subsequently, the scientific community was able to repeat Jenner’s experiments and obtained the same results.
This is how the first “vaccines” were invented: applying a weaker strain of a virus to immunize the person against the stronger and more harmful virus. Currently the same principle is used for various diseases. The term “vaccine” comes from this first form of immunization with a bovine virus.
- You can apply the scientific method
The scientific method is a way of testing hypotheses. In order to be applied, it is necessary to be able to carry out an experiment.
For example, let’s say you’re always very sleepy during your math class.
- your observation is: Dream in math class.
- One possible hypothesis is: You’re sleepy in math class because you didn’t get enough sleep the night before.
To carry out the experiment that proves or refutes the hypothesis, it is very important that you do not change anything in your behavior, except the hours of sleep: you must have the same breakfast, sit in the same place in the class, talk to the same people. - Experiment: The night before math class you will go to sleep an hour earlier than usual.
If you stop feeling sleepy during math class after doing the experiment multiple times (don’t forget the importance of doing the experiment multiple times) the hypothesis will be confirmed. If you continue to feel sleepy, you will need to develop new hypotheses.
For example:
- Hypothesis 1. An hour of sleep was not enough. Repeat the experiment increasing two hours of sleep.
- Hypothesis 2. Another factor intervenes in the sensation of sleep (temperature, food consumed during the day). New experiments will be designed to evaluate the incidence of other factors.
- Hypothesis 3. It is math that makes you sleepy and therefore there is no way around it.
As can be seen from this simple example, the scientific method is demanding when it comes to drawing conclusions, especially when our first hypothesis is not proven.