What is the experimental method?
He experimental method It is a quantitative research method that consists of testing the validity of a hypothesis by subjecting it to experimentation. It is the most used in the exact sciences, although it has also been used successfully in psychology and education.
The experimental method consists in the identification of the relevant variables for the investigation, in the design of experiments and in the observation of the changes that these undergo or generate after their execution.
This method allows researchers to manipulate the variables. In this way, precise cause-effect relationships can be established between a control sample (variables are not manipulated) and an experimental sample (variables manipulated).
For the analysis of the experimental results, statistical instruments are preferred, which provide exact data and allow to observe patterns that cannot be detected with the naked eye.
Characteristics of the experimental method
The experimental method is distinguished by these five characteristics:
1. It is a kind of quantitative method
Its objective is to determine the validity of a hypothesis through experimentation and statistical analysis. It provides specific results.
2. It takes place under controlled conditions
Whether in the laboratory or in field research, researchers are in control of all factors that can influence the outcome of the experiment.
3. Researchers can manipulate variables
We work with a control sample (in which no variable is manipulated) and an experimental sample, whose variables are manipulated according to the requirements of each investigation.
4. It consists of comparing the variables
Experimental research is about observing the changes that have occurred in the variables after subjecting them to experimentation, and comparing them with the variables of the control group.
5. Use dependent and independent variables
The variable that has been manipulated by the researchers is called independent. The dependent variables are those that are altered due to the manipulation of the independent variable.
Steps of the experimental method
In general, to apply the experimental method to any research object, the following steps must be fulfilled:
1. State the research problem
Answer the question: what exactly do you want to know? Examples: What is the effect of a high-fat diet on the body of cats. How effective is rosemary to cure baldness.
2. Develop a hypothesis
A hypothesis is a likely answer to the research problem. For example, that in cats a high-fat diet clogs the arteries and can cause death.
3. Design of the experiment
To know if our hypothesis is correct or false, it is necessary to test it. To do this we must identify the relevant variables and design an experiment. The ideal would be to carry it out several times.
4. Collect the data and interpret the results
Statistical resources are of great help when it comes to analyzing the results and perceiving patterns that are invisible to the naked eye.
5. Draw conclusions
The interpretation of the results will allow us to conclude if the proposed hypothesis is correct or erroneous.
Advantages of the experimental method
1. Experiments can be reproduced
Since it is carried out under well-defined and controlled conditions, an experiment can be replicated by other researchers to confirm or not the results.
2. The results are specific
The experimental method makes use of the instruments of the exact sciences: calculation, measurement, statistical analysis, so that its results are expressed in a quantifiable and specific way.
3. It is allowed to manipulate the variables
The aim is that researchers have the freedom to focus on the variables they consider relevant and design specific experiments for them.
4. It allows to identify the cause-effect relationship between the variables
By manipulating a certain variable, and observing the effects that this manipulation has on other variables, researchers are able to identify cause-effect relationships.
5. It is very productive in the exact sciences
The experimental method is especially fruitful in the exact sciences, where it is considered that if a theory has not been confirmed by experimentation, it is not truly science.
Disadvantages of the experimental method
1. It takes place in an artificial environment
Since the experiments are carried out under very controlled conditions, there is no guarantee that the results are 100% applicable in the “real” world.
2. It can raise ethical dilemmas
As for example, in the case of experimentation on humans, or because of the cruelty of some experiments on animals.
3. It does not give good results if the variables are not very precise
For example, an investigation wants to know if listening to music distracts workers and reduces their performance. But how to quantify the distraction variable? How to isolate it from other variables present in job performance? In these cases, the application of a qualitative method is more appropriate.
4. It can be expensive
The application of the experimental method requires highly specialized scientists and very complex and expensive equipment, such as the particle accelerator in Geneva, Switzerland. Ensuring that an environment is 100% controlled is more difficult and costs more.
5. It can take a long time
To draw a valid conclusion from a scientific point of view, it is necessary to replicate the same experiment several times or carry out more than one, which requires a lot of time.
Examples of experimental method
Vegetable consumption and hypertension
A researcher wants to know if eating vegetables influences having high blood pressure. An experimental group of 500 people consume vegetables every day for 2 months. The control group, also of 500 people, never consumes vegetables.
Garlic consumption and immune system
A researcher wants to know if eating garlic improves the immune system. An experimental group of 500 people consume garlic daily for 1 month. The control group, also of 500 people, does not consume it. The white blood cell level of both groups is measured.
Fertilizer and crop growth
A farmer wants to know if a fertilizer makes his crops grow faster. He applies the fertilizer to an area of 500 square meters of a crop, leaving another area of the same size without application.
Physical exercise and wellness
A doctor wants to know if the daily practice of physical exercise influences the well-being of people. An experimental group of 1000 people practices 1 hour of daily physical exercise, 5 times a week, for 90 days. The control group, also of 1000 people, does not exercise. The level of endorphins (feel-good hormones) is measured after 90 days.
Meditation practice and stress
A psychologist wants to know if the practice of meditation influences the level of stress. An experimental group of 100 people practices meditation daily for 6 months. A control group, also of 100 people, does not practice it. After 6 months, the stress level is measured.
dream and memorization
A researcher wants to know if the hours of sleep influence the ability to memorize. An experimental group of 200 people sleeps 8 hours each night and a control group sleeps 5-6 hours. It is concluded that people who sleep more memorize more effectively.
Swiss particle accelerator
These are vast underground facilities where physicists collide subatomic particles at the speed of light. This experiment allows them to know more deeply the nature of matter.
the rocks of mars
One of the objectives of the missions to the planet Mars that were sent during 2021 was to collect rocks from the Martian soil and bring them to Earth, where they will be subjected to various experiments to find out their nature and composition.
The reinforcements of the vaccine against covid-19
It was an experimental investigation that determined, after the analysis of the level of immunoglobulins, that in a significant percentage of the population sample the antibodies against covid-19 became undetectable after seven months, and that therefore a reinforcement of the vaccine.
Advances in the fight against cancer
Recently, experimental research showed that cardamonin, a natural compound present in cardamom, can be therapeutic for triple negative breast cancer.