Dependent vs Independent Variables
The mathematical tools used to keep the control of an experiment in a quantitative way are called dependent and independent variables. By using both variables simultaneously, we can reach up to a conclusion in an accurate manner. Both terms, dependent and independent variables, are related with each other. In fact, dependent variables depend upon independent variables as independent variables are presumed to determine dependent variables.
The variable that is manipulated in an experiment by the researcher is called independent variable. Basically, independent variables are those assumed values which have direct impact on dependent variables and have power to influence them. The independent variables or experimental variables can be changed according to requirement. The reason is that, if we assign same experiment to different persons and they hypotheses the values of independent variables according to their conditions, then independent variables could be different for same experiment. For example, if we want to see the impact of different quantity of fertilizer on plant growth, then the amount of fertilizer is independent variable as its quantity is changeable. In short, any value which is controllable is independent variable.
A dependent variable or response variable depends upon independent variable. Any change in independent variable influence the dependent variable. Actually, dependent variables are those values which are actually measured by the researcher not hypothesized. For example, if we are measuring the impact of different quantity of fertilizer on plant growth, then the characteristics of plant which show this impact are dependent variables like growth rate of plant in terms of height and weight. In other words, any value in an experiment which is uncontrollable is dependent variable. In this example, you can not control the growth of plant as it depends upon the quantity of fertilizer, which is being applied. So, as the quantity of fertilizer will change, your dependent variable means plant growth will vary.
Difference between dependent and independent variables
• For one independent variable, there may be more than one dependent variable. On the contrary, for more than one dependent variable, there is always one independent variable.
• The value of independent variable is changeable, while we cannot change the value of dependent variable.
• The independent variable is controllable, while we cannot control the value of dependent variable.
• Dependent variable depends upon independent variable, as when independent variable will change, there must be a change in the value of dependent variable. On the other hand, there is no impact of dependent variable upon independent variable/
• The value of independent variable is that which is manipulated in an experiment, while dependent variable is that value, which is observed by the researcher in an experiment
Though, dependent and independent variables have different concepts in an experiment. However, it is not possible to reach a proper conclusion without using both variables in a relation because independent variable is manipulated to see the results of dependent variables. Hence, for reaching an ultimate conclusion, it is very necessary to use both variables in an accurate manner.