In the course of writing your thesis, one of the first terms that you encounter is the word variable. Failure to understand the meaning and the usefulness of variables in your study will prevent you from doing good research. What then are variables and how do you use variables in your study? I explain the concept below with examples of variables commonly used in research.
You may find it difficult to understand just what variables are in the context of research especially those that deal with quantitative data analysis. This initial difficulty about variables becomes much more confusing when you encounter the phrases “dependent variable” and “independent variable” as you go deeper in studying this important concept of research as well as statistics.
Understanding what variables mean is crucial in writing your thesis proposal because you will need these in constructing your conceptual framework and in analyzing the data that you have gathered. Therefore, it is a must that you should be able to grasp thoroughly the meaning of variables and ways on how to measure them. Yes, the variables should be measurable so that you will be able to use your data for statistical analysis.
I will strengthen your understanding by providing examples of phenomena and their corresponding variables below.
Definition of Variables and Examples
Variables are those simplified portions of the complex phenomena that you intend to study. The word variable is derived from the root word “vary”, meaning, changing in amount, volume, number, form, nature or type. These variables should be measurable, i.e., they can be counted or subjected to a scale.
The following examples of phenomena from a global to a local perspective. The corresponding list of variables is given to provide a clear illustration of how complex phenomena can be broken down into manageable pieces for better understanding and to subject the phenomena to research.
- Phenomenon: climate change
Examples of variables related to climate change:
- sea level
- the amount of carbon emission
- the amount of rainfall
- Phenomenon: Crime and violence in the streets
Examples of variables related to crime and violence:
- number of robberies
- number of attempted murders
- number of prisoners
- number of crime victims
- number of laws enforcers
- number of convictions
- number of car napping incidents
- Phenomenon: poor performance of students in college entrance exams
Examples of variables related to poor academic performance:
- entrance exam score
- number of hours devoted to studying
- student-teacher ratio
- number of students in the class
- educational attainment of teachers
- teaching style
- the distance of school from home
- number of hours devoted by parents in providing tutorial support
- Phenomenon: Fishkill
Examples of variables related to fish kill:
- dissolved oxygen
- water salinity
- age of fish
- presence or absence of parasites
- presence or absence of heavy metal
- stocking density
- Phenomenon: Poor crop growth
Examples of variables related to poor crop growth:
- the amount of nitrogen in the soil
- the amount of phosphorous in the soil
- the amount of potassium in the ground
- the amount of rainfall
- frequency of weeding
- type of soil
Notice in the above examples of variables that all of them can be counted or measured using a scale. The expected values derived from these variables will, therefore, be in terms of numbers, amount, category or type. Quantified variables allow statistical analysis. Variable correlations or differences are then determined.
Difference Between Independent and Dependent Variables
Which of the above examples of variables are the independent and the dependent variables? The independent variables are just those variables that may influence or affect the other variable, i.e., the dependent variable.
For example, in the first phenomenon of climate change, temperature (independent variable) may influence sea level (dependent variable). Increased temperature will cause expansion of water in the sea. Thus, sea level rise on a global scale may occur. In the second phenomenon, i.e., crime and violence in the streets, the independent variable may be the number of law enforcers and the dependent variable is the number of robberies.
I will leave to you the other variables so you can figure out how this works.
How will you know that one variable may cause the other to behave in a certain way? Finding the relationship between variables require a thorough review of the literature. Through a review of the relevant and reliable literature, you will be able to find out which variables influence the other variable. You do not just simply guess relationships between variables. The whole process is the essence of research.
At this point, I believe that the concept of the variable is now clear to you. Share this information to your peers who may have difficulty in understanding what the variables are in research.
©2012 October 22 P. A. Regoniel