Variables are simply factors that represent properties, qualities, or characteristics of a person, thing, or concept. Any research paper like a thesis or dissertation requires relevant variables to be defined correctly. They can be as simple as demographic characteristics such as age, gender, or income (Marudhar, 2018). Other times they can be more complex like the psychological traits of an individual. Researchers do a thorough literature review to identify these complex variables.
Different types of variables in a research
Variables of any study are of four main types.
A dependent variable is a variable that is dependent on the value of another variable. So if anything in the first variable changes then the dependent variable changes too.
‘Weight’ is often dependent on the ‘age’ of an individual. Here, ‘weight’ is the dependent variable.Marudhar, 2018; USCLibraries, 2017
An independent variable is a variable that is unaffected by other variables of the study. In studies, these variables could be regarded as the factors affecting the key research term.
‘Age’ is not related to ‘gender’, i.e. if a person’s gender changes then his age does not change. Therefore they both are independent variables.
A demographic variable is a variable that represents the basic demographic characteristics of the nature of respondents included in the study. They are neither independent nor dependent. Common demographic variables are age, gender, income, location, profession and marital status.
An extraneous variable is also known as an intervening variable and they make a relationship stronger or weaker.
Categorising relevant variables as dependent and independent variables
Literature review for major studies serves as a major methodological tool to answer research questions. It aims to delve deep into the background of the research topic. For this, researchers study review relevant research papers published in reputable publications.
With the empirical review of the literature in the above example, it can be derived that project performance is the dependent variable represented by:
- project success,
- strategic performance,
- and operational performance.
While aspects like:
- system management,
- stakeholder management,
- risk management,
- integrity management,
- cost management,
- audit management,
- project manager competency,
- project team competency,
- rules and procedure compliance,
- subcontractor services,
- human resource management,
- task management,
- schedule management and,
- feasibility study
are possible independent variables.
Presenting the identified relevant variables in the conceptual framework
In the literature review, researchers commonly use a diagram known as a conceptual framework to map out the linkage between the variables. A conceptual framework is a visual or written representation of the possible or expected relationships between variables (Swaen, 2021). A conceptual framework helps to identify the correct way to test the relationship between two variables. Thus, the presentation of variables in the conceptual framework should be to state the mix of variables and their linkage based on existing studies (Regoniel, 2015).
From the above example of the empirical review of literature, the conceptual framework can be presented as:
- System management
- Stakeholder management
- Risk management
- Cost management
- Audit management
- Subcontractor services
- Human resource management
- Task management
- Schedule management
Dependent variable components
- Project success
- Strategic performance
- Operational performance
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- Kroelinger, M. (2002). Strategy for Literature Review Process.
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- Ramesh, E., Babu, D. R., & Rao, P. R. (2018). The impact of project management in achieving project success- Empirical study. International Journal of Mechanical Engineering and Technology, 9(13), 237–247.
- Regoniel, P. (2015). Conceptual Framework: A Step by Step Guide on How to Make One. SimplyEducate. simplyeducate.me/2015/01/05/conceptual-framework-guide/
- Swaen, B. (2021). Constructing a conceptual framework. Scribbr. https://www.scribbr.com/methodology/conceptual-framework/
- USCLibraries. (2017). Research Guides. Usc.Edu. https://libguides.usc.edu/writingguide/background
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