variable manipulation

A manipulated variable refers to an independent variable that is used in an experiment. It is given the term manipulated because it is the variable that can be changed. In other words, it is possible for you to increase or decrease this variable at will ahead of time. You should only have a single manipulated variable in an experiment at a time.

There are generally three variables in an experiment, they are:

1. The manipulated variable. This is also known as the independent variable and it is that which you can control.
2. The controlled variable. This refers to that variable that is kept constant in an experiment.
3. The responding variable. This refers to that variable or variables that occurs as a result of an experiment. In other words, it can be said to be the output variable in an experiment.

EXAMPLE: in case you want to find out the effect that will be brought about by a change in the length of the lessons on the student’s performance in exam, the lesson time will be the manipulated variable. This is due to the fact that this is what is being changed. Controlled variables can be things that such as the satisfaction of the students, the conduciveness of the environment among others. They should per harps be tested at the same time. The exam success is the responding variable. This is measured by the scores that the students get in the exam.

There exist input variables of two types in process control. These variables are the disturbance variables and the manipulated variables. In this context, the term manipulated variable is used to refer to the input controlled by the control system or the process operator. These variables are adjusted via the process operator in order to maintain the variables that are controlled in the system at settings that are constant. The disturbance variable on the other hand is another input type and it is known to have an effect on the process outputs. The disturbance variables unlike the manipulated variables, they cannot be adjusted or changed by the control system.

Example: assuming a driver wants to keep the speed of his car constant. Factors like acceleration, tire pressure and friction which are external factors may result to the speed of the car changing. An accelerator may keep the speed constant.  The process of figuring out the time to use the accelerator or not is the control. The accelerator’s state is what is being referred to as the manipulated variable. The speeding up is the process and the speed itself is what is being referred to as the controlled variable.

USAGE EXAMPLES.

• In case you wish to find out if a certain action is responsible for the occurrence of an event, you can try making use of a manipulated variable to determine if indeed it is the one.
• In case a business is struggling, you can try using a manipulated variable to establish the cause of the problem.
• A manipulated variable is responsible for the outcomes of an experiment, so in case something is not perfect try using the manipulated variable to establish the cause.