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 should these be dealt with? 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 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 how these are measured. Yes, the variables should be measurable in order 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 and the corresponding list of variables are given to provide a clear illustration of how a 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, temperature, amount of carbon emission, 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 law enforcers, number of convictions, number of carnapping 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 study, student-teacher ratio, number of students in class, educational attainment of teachers, teaching style, distance of school from home, number of hours devoted by parents in providing tutorial support
- Phenomenon: Fish kill
- Examples of variables related to fish kill: dissolved oxygen, water salinity, temperature, 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: amount of nitrogen in the soil, amount of phosphorous in the soil, amount of potassium in the soil, amount of rainfall, frequency of weeding, type of soil, temperature
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. When variables can be quantified, statistical analysis will then be possible. Correlations or differences between variables can then be 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) because 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? This is not just a matter of guesswork, so you will need to review related literature regarding the phenomena that you are interested in to find out which variables actually influence the other variable. This is the essence of research.
At this point, I believe that the concept of variable is now clear to you. Share this information to your peers who may have difficulty in understanding what the variables are in research.