The experiments would form part of the methodological framework of our thesis. They are procedures where a particular action is carried out and, then, the results are observed and analyzed. The scientific experiment contemplates the controlled and intentional intervention of the research variables. This with the intention of measuring the effects caused.
When an experiment is done, we work with two types of variables: independent and dependent. The first are the manipulations or stimuli carried out by the researcher. Meanwhile, the second ones are the effects or consequences of the independent variables.
When dealing with controlled situations, the researcher can not experiment with past events or phenomena that exceed their physical scope and resources. It is also not possible to carry out experiments that violate ethical parameters, such as attacking the physical and emotional well-being of a living being.
WHAT REQUIREMENTS SHOULD A SCIENTIFIC EXPERIMENT COMPLY WITH?
1- HANDLING OF INDEPENDENT VARIABLES
Dependent variables are not intervened because they are an effect or consequence. They can only be measured. On the contrary, the independent ones, when considered as causes, must be controlled in a rigorous manner and according to certain degrees:
By presence and absence: an experiment with group division is carried out. The variable is present in one and not in another. They are comparative experiments, for example, the case studies with test drugs and placebos.
Several degrees: the variable is manipulated in different quantities to measure the consequences by levels. For example, the study of the effects on voters of verbal violence in political discourses, with divisions of variables in “very violent”, “moderate violence” and “without violence”.
By modality: the variables are controlled by reason of the mode and not the quantity. This is the case of experimentation with colors, speech forms, media, etc.
The manipulation of the variables will depend on the theory that we have developed, because a variable is a translation of a concept, the empirical manifestation of the theory.
2- VALID MEASUREMENT OF THE EFFECTS
When the experimentation is done, the measurement of the consequences is very important. In addition, it must respond to the intentions of the independent variables. For example, if we try to experiment with new teaching methods to improve understanding in children and, in measurement, we focus on recording memorization and attention; but not the level of understanding achieved, the experiment is not reliable.
3- TOTAL CONTROL OF THE EXPERIMENT
It refers to knowing with certainty what is happening at each step of the experiment. The relationship between independent and dependent variables must be controlled by the researcher. Nothing can escape its supervision. In this way, it is possible to determine with certainty the cause and effect relationship, also to demonstrate the validity of the whole experiment.
The experiments require careful treatment, therefore the researcher must take into account situations that could invalidate his work, such as: a wrong design of the measuring instrument, external events that occur during the experiment or that the divisions of the groups or tests are not same.