Question

In an experiment, the factor that we measure is called the:
A. conclusion
B. independent variable
C. controlled variable
D. dependent variable

Answer 1

Hint: In an experiment, we need variables on which we have control and what we can choose and can do manipulation. So we need such a variable whose value will not depend on other values or other terms.

Complete answer:
A variable is nothing but what is measured or manipulated in an experiment. Variables provide the means by which scientists structure their observations in the experiment. Identifying the variables in an experiment provides a solid understanding of the experiment which we have performed and what the key findings in the experiment are going to be.

To identify the variables, read the lab procedure carefully which is described in the lab manual. Determine what you will be measuring and what you will be manipulating for each measurement in the experiment. The value(s) you are manipulating is known as the independent variable. Write down the dependent and independent variables. In more advanced labs, you may have multiple variables, more than one independent and dependent variable.

An independent variable is the variable you have control over and what you can choose and manipulate. In some cases, each time, you may not be able to manipulate the independent variable. It may be something that already exists over there and which is fixed & something you would like to evaluate in accordance to how it affects something else, the dependent variable.

A dependent variable is what you measure and what is affected during the experiment. The dependent variable responds to the independent variable, it is called as dependent because it "depends" on the independent variable.

Example: You are interested in how stress affects heart rate in human’s body. Your independent variable will be the stress and the dependent variable will be the heart rate. You can directly manipulate stress levels in your human body and can measure how those stress levels change heart rate.
Hence In an experiment, the factor that we measure is called the independent variable.

So, the correct answer is “Option B”.

Note:
The value(s) you are observing/recording is called the dependent variable. Independent variable is usually what you think will affect the dependent variable. If we consider scientific experiment, you cannot have a dependent variable without an independent variable. It is possible that you have experiments in which you have multiple variables. It may be more than one dependent variable and/or independent variable. This is especially true if you are conducting an experiment with multiple stages or sets of procedures in the experiment. In these experiments, there may be more than one set of measurements with different variables.