- What are research variables?
- 1 - Independent variable
- 2 - Dependent variable
- Examples of independent and dependent variables
- Example
- Controlled variables or control
- Example 1
- Example 2
- References
Research variables or scientific experiment are factors that can be measured, manipulated, and are likely to change during research.
They are an important part of projects and scientific checks, they are totally necessary when conducting any research.
In conducting a scientific investigation, one of the first terms encountered is the word variables. Understanding the meaning and usefulness of this term will go a long way toward doing a good job.
The word “variable” comes from the Latin “variabilis”, a word that defines what is subject to some type of change (Buddies, 2017). It is something that is changeable, mutable, therefore, we can define variable as something that varies or changes.
A variable is anything that can take different numerical or categorical values. The variables represent a concept of vital importance within a research project, they are concepts that form the research hypotheses.
What are research variables?
In science, a variable is any element, condition or factor that can be controlled, varied or measured within an investigation (Porto & Gardey, 2008).
Since the variable represents a characteristic that shows differences, it is worth saying that a variable is generally anything that can assume different categorical or numerical values.
Researchers use experimentation to establish a link between different variables, looking for a cause and effect relationship (Wigodski, 2010).
Cause and effect relationships explain why things happen and make it possible to reliably predict what will happen if something is done in a certain way.
In other words, scientists conduct research to observe or measure whether changes in one thing cause another to vary repeatedly.
Scientific checks have several kinds of variables. The variation can be in quantity, intensity or type.
There are many types of variables, but the main ones for the vast majority of research methods are independent variables and dependent variables.
1 - Independent variable
The values of these types of variables do not depend on the value of others. It is conceptualized as the cause or phenomenon to be investigated and is identified as the cause or antecedent. This variable can be manipulated or changed by the scientist or research entity.
2 - Dependent variable
The values of these variables depend on other variables as their name explicitly indicates.
Dependent variables are subject to change by action of other elements. The observation or measurement of this variable will change as the independent variable is altered.
The dependent variables are those that are measured, the observation is focused on them to see the response to the change in the independent variable. They are the result of the phenomenon that is being investigated.
Examples of independent and dependent variables
If we want to find out the reaction produced by sound in human behavior, sound would be the variable that the researcher manipulates - the independent one - and the reaction of the subject to changes in sound intensity, would be the dependent variable.
Example
You can change the position of the wings of a model aircraft to see how they affect speed and height in flight.
The position of the wing would be the independent variable, because it is changed intentionally. Speed and height would be the dependent variables since they change depending on the position given to the wing.
Controlled variables or control
The control variable is the experimental element that is permanent and invariable during the investigation. This variable strongly influences the experimental results and must be kept constant during the experiment to be able to test the relationship between the dependent and independent variables.
The control variable itself is not of primary interest to the experimenter, yet it must be observed as carefully as the dependent variables.
If the controlled variables do not hold, the investigator will not know whether the independent variable caused the change in the dependent variable or whether it was due to the controlled variable.
In any investigation, the lack of isolation of the controlled variables will seriously compromise the validity of the study (Shuttleworth, 2008).
In many investigations, only one or two variables are measured at a time. Any other factor that intervenes in the results must be controlled correctly.
Its effect on the results must be equalized or eliminated, exerting the same influence on the different sample groups.
Example 1
Research will be done on a cosmetic product to remove skin blemishes. Two groups of women with similar conditions are selected to carry out the study.
The main group will apply the cosmetic to be investigated and the other will use a different product.
The independent variable would be the application of the product and the dependent variable if the skin spots disappear or not.
There are variables that must also be controlled for the study and that could affect the result. In this case, it would be age, ethnicity or exposure to the sun during the test time. These would be the controlled variables.
Example 2
A scientist conducts research to prove that the use of a vitamin can increase people's life expectancy.
The independent variable is the amount of vitamin that is given to the investigated subjects. This is controlled by the investigator.
The dependent variable or the variable that is being affected by the independent variable is the life span.
The researcher must take into account the controlled variables, since the study may be affected if factors such as gender, health status, diet… are not taken into account (REGONIEL, 2012).
References
- Buddies, S. (2017). Variables in Your Science Fair Project. Retrieved from What are Variables ?: sciencebuddies.org
- Porto, JP, & Gardey, A. (2008). Definition of. Obtained from Definition Of Variables: definicion.de
- REGONIEL, PA (October 22, 2012). I. Retrieved from What Are Examples Of Variables In Research ?: simplyeducate.me
- Shuttleworth, M. (August 9, 2008). com. Obtained from Research variables: explorable.com
- Wigodski, J. (2010 July 10). Investigation methodology. Obtained from Variables: methodologiaeninvestigacion.blogspot.com.co.