SCIENTIFIC METHOD: THE 6 STEPS AND THEIR CHARACTERISTICS (EXAMPLE) - SCIENCE - 2024

The scientific method is a process used in the branches of science to test a scientific hypothesis through observation, questioning, hypothesis formulation, and experimentation. It is a rational way of obtaining objective and reliable knowledge.

The scientific method therefore has a series of characteristics that define it: observation, experimentation, and asking and answering questions. However, not all scientists follow this process exactly. Some branches of science can be more easily tested than others.

The steps of the scientific method: question, investigation, hypothesis formulation, experiment, data analysis, conclusions.

For example, scientists studying how stars change as they age or how dinosaurs digested their food cannot advance the life of a star by a million years or conduct studies and tests with dinosaurs to test their hypotheses.

When direct experimentation is not possible, scientists modify the scientific method. Although it changes with almost every scientific investigation, the goal is the same: to discover cause and effect relationships by asking questions, collecting and examining data, and seeing if all the available information can be combined into a logical answer.

On the other hand, a scientist often goes through the stages of the scientific method again, as new information, data or conclusions may make it necessary to go through the steps again.

For example, a scientist may hypothesize "overeating accelerates aging," conduct an experiment, and draw a conclusion. You could then go through the steps again, starting with another hypothesis, such as "eating too much sugar accelerates aging."

What is the scientific method and what is it for?

The scientific method is an empirical method of investigation that serves to obtain new knowledge and information. "Empirical" means that it is based on reality, uses data; it is the opposite of "theoretical." Therefore, scientists use the scientific method to learn about reality, collecting data and conducting experiments. It can be divided into six steps / phases / stages that apply to all types of research:

-Question based on observation.

-Investigation.

-Formulation of the hypothesis.

-Experimentation.

-Analysis of data.

-Reject or accept the hypothesis (conclusions).

Next I will show the fundamental steps that are taken when doing an investigation. So that you understand it better, at the end of the article I will leave an example of the application of the steps in a biology experiment; in the discovery of the structure of DNA.

Main characteristics of the scientific method

- Use observation as a starting point.

- Ask questions and answers. To formulate a hypothesis, the scientist asks questions and answers in a systematic way, seeking to establish cause-effect relationships in aspects of reality.

- Requires verification, that is, the results need to be verified by various scientists.

- Generates refutable conclusions. If the conclusions cannot be verified, the scientific method cannot be applied.

- Produces reproducible results; the experiments can be replicated by scientists to try to obtain the same results.

- It is objective; it is based on experimentation and observation, not subjective opinions.

What are the steps of the scientific method? What they consist of and their characteristics

Step 1- Ask a question based on the observation

The scientific method begins when the scientist / researcher asks a question about something they have observed or what they are investigating: How, what, when, who, what, why, or where?

Examples of observations and questions:

- Louis Pasteur observed under a microscope that the silkworms of the south of France had diseases infected by parasites.

- A biologist observes under the microscope that the presence of certain types of cells improves the symptoms of smallpox. You might ask, do these cells fight the smallpox virus?

- Albert Einstein, when he was developing his theory of special relativity, asked himself: What would you see if you could walk next to a ray of light as it propagates through space?

Step 2- Investigation

This step consists of doing research, gathering information to help answer the question. It is important that the information collected is objective and from reliable sources. They can be investigated through internet databases, in libraries, books, interviews, research, among others.

There are several types of scientific observation. The most common are direct and indirect.

Step 3- Hypothesis formulation

The third stage is the formulation of the hypothesis. A hypothesis is a statement that can be used to predict the outcome of future observations.

Examples of hypotheses:

• Soccer players who train regularly taking advantage of time, score more goals than those who miss 15% of training sessions.
• New parents who have studied higher education, are in 70% of the cases more relaxed in childbirth.

A useful hypothesis must allow predictions by reasoning, including deductive reasoning. The hypothesis could predict the outcome of an experiment in a laboratory or the observation of a phenomenon in nature.

If the predictions are not accessible by observation or experience, the hypothesis is not yet testable and will remain to that unscientific measure. Later, a new technology or theory could make the necessary experiments possible.

Step 4- Experimentation

Experiment case with humans.

The next step is experimentation, when scientists perform so-called science experiments, in which hypotheses are tested.

The predictions that the hypotheses attempt to make can be tested with experiments. If the test results contradict the predictions, the hypotheses are questioned and become less sustainable.

If the experimental results confirm the predictions of the hypotheses, then they are considered to be more correct, but they may be wrong and continue to be subject to further experiments.

To avoid observational error in the experiments, the experimental control technique is used. This technique uses the contrast between multiple samples (or observations) under different conditions to see what varies or remains the same.

Example

To test the hypothesis 'the growth rate of grass does not depend on the amount of light', one would have to observe and take data from grass that is not exposed to light.

This is called a "control group." They are identical to the other experimental groups, except for the variable under investigation.

It is important to remember that the control group can only differ from any experimental group by one variable. That way you can know that it is that variable that produces changes or not.

For example, grass outside in the shade cannot be compared to grass in the sun. Nor does the grass of one city with that of another. There are variables between the two groups in addition to light, such as soil moisture and pH.

Another example of a very common control group

Experiments to find out if a drug is effective in treating what is desired are very common. For example, if you want to know the effects of aspirin, you could use two groups in a first experiment:

• Experimental group 1, to which aspirin is provided.
• Control group 2, with the same characteristics as group 1, and to which aspirin was not provided.

Step 5: data analysis

After the experiment, the data is taken, which can be in the form of numbers, yes / no, present / absent, or other observations.

The systematic and careful collection of measurements and data is the difference between pseudosciences like alchemy, and sciences, like chemistry or biology. Measurements can be made in a controlled environment, such as a laboratory, or on more or less inaccessible or non-manipulable objects, such as stars or human populations.

Measurements often require specialized scientific instruments such as thermometers, microscopes, spectroscopes, particle accelerators, voltmeters…

This step involves determining what the results of the experiment show and deciding the next actions to take. In cases where an experiment is repeated many times, statistical analysis may be necessary.

If the evidence has rejected the hypothesis, a new hypothesis is required. If the data from the experiment support the hypothesis, but the evidence is not strong enough, other predictions of the hypothesis should be tested with other experiments.

Once a hypothesis is strongly supported by the evidence, a new research question can be asked to provide more information on the same topic.

Step 6: Conclusions. Interpret the data and accept or reject the hypothesis

For many experiments, conclusions are formed on the basis of an informal analysis of the data. Simply ask, do the data fit the hypothesis? it is a way of accepting or rejecting a hypothesis.

However, it is better to apply a statistical analysis to the data, to establish a degree of 'acceptance' or 'rejection'. Mathematics is also useful for evaluating the effects of measurement errors and other uncertainties in an experiment.

If the hypothesis is accepted, it is not guaranteed to be the correct hypothesis. This just means that the results of the experiment support the hypothesis. It is possible to duplicate the experiment and get different results next time. The hypothesis may also explain the observations, but it is the wrong explanation.

If the hypothesis is rejected, it may be the end of the experiment or it can be done again. If you repeat the process, you will have more observations and more data.

Other steps are: 7- Communicate results and 8- Check the results by replicating the research (carried out by other scientists)

If an experiment cannot be repeated to produce the same results, this implies that the original results could have been wrong. As a result, it is common for a single experiment to be performed multiple times, especially when there are uncontrolled variables or other indications of experimental error.

To obtain significant or surprising results, other scientists may also try to replicate the results themselves, especially if those results are important to their own work.

Real example of scientific method in the discovery of the structure of DNA

The history of the discovery of the structure of DNA is a classic example of the steps of the scientific method: in 1950 it was known that genetic inheritance had a mathematical description, from the studies of Gregor Mendel, and that DNA contained genetic information.

However, the mechanism of storage of genetic information (i.e. genes) in DNA was unclear.

It is important to note that not only Watson and Crick participated in the discovery of the structure of DNA, although they were awarded the Nobel Prize. Many scientists of the time contributed knowledge, data, ideas and discoveries.

Question from observations

Previous research on DNA had determined its chemical composition (the four nucleotides), the structure of each of the nucleotides, and other properties.

DNA had been identified as the carrier of genetic information by the Avery-MacLeod-McCarty experiment in 1944, but the mechanism of how genetic information is stored in DNA was unclear.

The question could therefore be:

Investigation

The people involved, including Linus Pauling, Watson or Crick, investigated and searched for information; in this case possibly research of the time, books and conversations with colleagues.

Hypothesis

Linus Pauling proposed that DNA could be a triple helix. This hypothesis was also considered by Francis Crick and James D. Watson but they discarded it.

When Watson and Crick learned of Pauling's hypothesis, they understood from the existing data that he was wrong, and Pauling would soon admit his difficulties with that structure. Therefore, the race to discover the structure of DNA was to discover the correct structure.

What prediction would the hypothesis make? If DNA had a helical structure, its X-ray diffraction pattern would be X-shaped.

Therefore, the hypothesis that DNA has a double helix structure would be tested with the X-ray results / data. Specifically, it was tested with X-ray diffraction data provided by Rosalind Franklin, James Watson and Francis Crick in 1953.

Experiment

Rosalind Franklin crystallized pure DNA and performed X-ray diffraction to produce photograph 51. The results showed an X shape.

Experimental evidence supporting the Watson and Crick model was demonstrated in a series of five papers published in Nature.

Of these, the Franklin and Raymond Gosling paper was the first publication with X-ray diffraction data to support the Watson and Crick model.

Analysis and conclusions

When Watson saw the detailed diffraction pattern, he immediately recognized it as a helix.

He and Crick produced their model, using this information along with previously known information about the composition of DNA and about molecular interactions, such as hydrogen bonding.

History

Because it is difficult to define exactly when the scientific method began to be used, it is difficult to answer the question of who created it.

The method and its steps evolved over time and the scientists who were using it made their contributions, evolving and refining little by little.

Aristotle and the Greeks

Aristotle, one of the most influential philosophers in history, was the founder of empirical science, that is, the process of testing hypotheses from experience, experimentation, and direct and indirect observation.

The Greeks were the first Western civilization that began to observe and measure to understand and study the phenomena of the world, however there was no structure to call it the scientific method.

Muslims and the golden age of Islam

Actually, the development of the modern scientific method began with Muslim scholars during the Golden Age of Islam, in the 10th to 14th centuries. Later, the philosopher-scientists of the Enlightenment continued to refine it.

Among all the scholars who contributed, Alhacen (Abū 'Alī al-Ḥasan ibn al-Ḥasan ibn al-Hayṯam), was the main contributor, considered by some historians as "the architect of the scientific method." His method had the following stages, you can see its similarity with those explained in this article:

-Observation of the natural world.

-Establish / define the problem.

-Formulate a hypothesis.

-Test the hypothesis through experimentation.

-Evaluate and analyze results.

-Interpret the data and draw conclusions.

-Publish the results.

Renaissance

The philosopher Roger Bacon (1214 - 1284) is considered to be the first person to apply inductive reasoning as part of the scientific method.

During the Renaissance, Francis Bacon developed the inductive method through cause and effect, and Descartes proposed that deduction was the only way to learn and understand.

Newton and modern science

Isaac Newton can be considered the scientist who finally refined the process until today it is known. He proposed, and put into practice, the fact that the scientific method needed both the deductive and the inductive method.

After Newton, there were other great scientists who contributed to the development of the method, including Albert Einstein.

Importance

The scientific method is important because it is a reliable way to acquire knowledge. It is based on basing claims, theories, and knowledge on data, experiments, and observations.

Therefore, it is essential for the advancement of society in technology, science in general, health and in general to generate theoretical knowledge and practical applications.

For example, this method of science is contrary to that based on faith. With faith, something is believed by traditions, writings or beliefs, without being based on evidence that can be refuted, nor can experiments or observations be made that deny or accept the beliefs of that faith.

With science, a researcher can carry out the steps of this method, reach conclusions, present the data, and other researchers can replicate that experiment or observations to validate it or not.

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