Concepts or constructs are important components of research but cannot be measure in research. After identifying the concept or constructs researcher must try to separate the different dimension of concept through operational definition. It help to develop the indicator. after identifying the indicator researcher define variables use in research.
In research, concept is commonly used but cannot be directly measured. The concept can be converted into variables by defining concept in operationally. In simple word, the concept that can be measured is called variable. The variable may be numerical or attributes which are attached and very according to time, place, institution and person. The variable is the important aspects of the research. The concept used for the study are measure from variables. Variable are anythings that can take on differing or varying values which mean that the value of variable vary from person to person, time to time or place to place but the meaning of variable are same to all. Thus, variable are the characteristics of person, groups, objects, ideas, feeling or other thing that researcher want to measure.
Variables are anything that can take on differing or varing values. It can be differ at various times for same subject or for same person. Variables is a symbol for which number are assigns.
In research, concept are resize by indicator and with the help of indicator concept are measure. The indicator are measure by the variable and by the help of variable it is measure. For example, rich is concept and income and assets old by person are the indicators to measure rich. Income of a person per year, total value of house, land, investment, car, etc. helps to measure the richness of person. So, these are variable of research.
The age of person, income of individual, yield of crops, religions etc are the example of variables which may be qualitative and quantitative in nature. When the qualitative nature of data is used the variable becomes qualitative which is also called categorical variables. Sex, marital status, religions etc. are the example of those variable. On the other hand when numerical data used in research is called quantitative variable. Age, income of individual quantity etc are the example of quantitative variable.
Generally, there are main 4 types of variables. They are:
- Dependent variable
- Independent variable
- Moderating variable
- Innervating variable
when the values of variable is depend to other variable this types of variable are dependent variable. In research the researcher focus to study, analysed and predict these variable by using independent variable. This is the variable that leads for investigation as viable factor. By analysis the dependent variable the investor find possible solution for research problem. If we recalled the law of demand the quantity Demand is Dependent variable which is determine by the price of the community.
The variable that is not affected by other variable is called independent variable. This variable are the input for the dependent variable. The research used it as the input for research. Independent variable is that variable which influence the dependent variable. If we recalled the law of demand price of the community is independent variable which determine the quantity demand.
Moderating variable is one that has a strong contingent effect on the independent variable and dependent variable. The present of moderating variable may change the original relationship between independent and dependent variables.
Mediating variable is also called Intervening. it is that variable that surfaces between the time the independent variable start operating to influence the dependent variable and the time their impact is felt on it. Mediating variables surfaces as a function of the independent variable operating in any situation, and helps to conceptualize and explain the influence of the independent variable on the dependent variable.