What Is an Independent Variable?

If you’ve ever studied science or math – which you probably do, since they’re largely mandatory – you’re already familiar with the concept of variables as things that change.

You may also remember that there is a difference Species of the variables. Here, we will focus on one type: independent variable. We’ll also look at dependent variables, where each type is determined by its relationship to the other.

What are the variables?

in experiments, Variables are factors that can or can be changed. Variables can be manipulated, measured or controlled.

For example, a bubble gum elasticity test experiment might use one known variable, brands of bubble gum, and then measure the resulting variable, bubble size, to determine the result.

A picture showing what a variable is

Experiments can measure quantities, feelings, actions/reactions, or anything in any other category.

dependent and independent variables

Independent and dependent variables are the two main types of variables found in experiments. The names of each variable provide useful clues regarding their respective roles.

To fully understand what an independent variable is and what it does, you need to understand what a dependent variable is and what it also does.

dependent variables

An image showing what the dependent variable is

The dependent variable is what is measured in an experiment or study.

Changes in the dependent variable occur as a result of the influence of the independent variable, but what these changes will be is unknown to the researchers at the beginning of the study. That’s why they experiment! The researchers want to know what those changes will be.

The dependent variable responds to the independent variable Changes in the dependent variable depend on the influence of the independent variable. See How does the name define the role of the dependent variable?

independent variables

An image showing what is an independent variable

The independent variable is self-contained. It is not affected or changed by any other variables. That is why it is called a standalone. If the value of the independent variable is changed, then this change is under the control of the researcher – it is not caused by other variables.

The independent variable is determined by the researcher. Its value is known to the researcher, in contrast to the dependent variable whose values ​​have not yet been determined by experiment.

The independent variable is the reason for a change in the dependent variable. This change is measured and recorded by the experimenter.

An image showing other names for independent variables

Other names for an independent variable:

  • manipulation variable
  • causal variable
  • explanatory variable
  • predictor variable
  • Factor
  • experimental variable

Quick test! Make sure you understand

Let’s test your initial understanding of variables.

Question #1: In the experiment to see if brands of bubble gum produced different sized bubbles, what was the independent variable?

Question 2: In an experiment to determine which of your favorite breakfast cereals stay crunchy in milk for the longest, what was the independent variable?

Remember – an independent variable is one that is not changed by other variables. Its value is known to the researcher.

answer 1: the independent variable … brands of chewing gum!

Then, the volume of bubbles (dependent variable) produced by each unique brand will be measured.

A picture showing how to find the independent variable

Answer 2: The independent variable is … favorite cereal brands!

Next, the length of time that each type of cereal remains crunchy (dependent variable) will be measured.

How do you define independent variables?

It may take some practice to feel confident in identifying the independent and dependent variables. These tips should help you while you train.

independent variable

  • “I know!” – The independent variable begins with “I.” It is the variable that the researcher knows. Put yourself in the researcher’s shoes and remind yourself “I” know the value of the independent variable. I know I use these brands of bubble gum or pills.
  • Ask yourself, “What is the researcher controlling?” The researcher cannot control the results or the effects, only the causes. The independent variable is the cause that produces an effect. This type of gum produces a bubble of a certain size.

An image showing how to find the dependent variable

dependent variable

  • The dependent variable has a value that the researcher does not know. When you think “depend” think Dr I do not know. The researcher does not know how big a bubble each brand of gum will produce.
  • Ask yourself, “What is being measured?” Your answer is the dependent variable. In the chewing gum experiment, bubble size is the dependent variable.

The “Write the Hypothesis” method

Sometimes writing an experiment’s hypothesis can help you identify variables.

Everyone says it with me: a hypothesis is an “educated guess”. Have you had flashbacks to your elementary school science class yet?

The hypothesis shows the cause (independent) and relationship (dependent) between the variables, and introduces the independent variable first.

A hypothesis is a proposed explanation – a testable prediction – made about the relationship between two variables. It explains what you expect to happen in an experiment and is based on some preliminary research.

A picture showing what the hypothesis is

Next, you will see if the results of the experiment show that your hypothesis was true or false. And if this is a “mistake”, it is not a bad thing. It’s a discovery—that’s how experiments work.

So let’s get back to gum and pills (this is the last time, I promise). You are back in science class and you are asked to identify the independent and dependent variables in each of those experiments. Here are your hypothesis options:

Experiment 1:

Experiment 2:

Did you notice something strange in the first statements of each pair?

It has no logical meaning.

The reason it is not understood is that it puts the effect in the place of the cause. They put the dependent variable in the role of ’cause’ and the independent variable in the role of ‘effect’, and produce irrational hypotheses (and statements in general).

The second phrases in each pair have meaning. They show the cause and effect relationship between the two variables. And since we know that the independent variable comes first in the hypothesis, you can now identify it easily!

Writing a research paper?

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When you explain your results, it’s important to make your writing as easily understandable as possible, especially if your experiment is complex. Our editing tool will help you reduce passive voice, remove ambiguous language, improve sentence length diversity, and clarify overused or repetitive words and phrases – all of which affect readability.

Academic essay with hypothesis extract

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Can you have more than one independent variable?

Yes. But having more than one independent variable makes the experiment more complicated. If you’re only here to work on a science fair project, I’d suggest keeping the amount of your independent variable limited to one.

Image display guide for using multiple independent variables

However, studies with more than one independent variable, when conducted by experts, often result in rich, multi-layered, and useful discoveries.

For example, we’ve heard a lot about vaccine trials, especially since 2020. Researchers typically run these trials in phases, looking at the vaccine’s effectiveness in different populations. These populations often differ according to age.

In these trials, the vaccine itself (administered) is an independent variable and another is age. Now researchers can see not just how effective the vaccine is, but how effective it is for people in different age groups.

You might be thinking, “But a researcher can’t control a person’s age.” And you’re right. However, in this case, researchers intentionally select subjects within certain age groups and thus control or manipulate them as an independent variable.

Additionally, studies with more than one independent variable allow researchers to observe and measure interactions between or between (if you have more than two), independent variables.

Are there other types of variables?

over there! And they can affect the validity of the experiment, so it is important to recognize them.

control variables

A control variable is something that is not measured in an experiment. It is not the independent or dependent variable, but its presence can affect the outcome of the experiment.

An image showing what the control variable is

For example, let’s say you are conducting a study on whether a particular exercise program affects weight loss.

Quickly! What are independent and dependent variables?

(IV = exercise program, DV = weight loss)

A straightforward experience, it seems.

But what if the participants had different eating habits? This is just one of many possible variables that must be so censored for. How could that happen?

Well, the researcher could give guidelines on calorie and food consumption, or ask participants to keep a food diary so that their diets can be counted when it’s time to analyze the study results.

Confusing or extraneous variables

Confounding variables, also called exogenous variables, affect the relationship between independent and dependent variables. They are variables that the researcher did not control and, as a result, confuse, confuse or distort the results.

An image showing the confusing variables

These variables influence the validity of the experiment, which is why it is so important for researchers to check and control the boxes before beginning their study.

Can you anticipate some confounding variables for this study? Here is the hypothesis:

Using a mobile phone before bed affects sleep.

any ideas?

I have a couple, although they don’t represent them all, I’m sure of.

Possible confounding variables

  • Caffeine consumption

  • sleep environment

Either of these two variables can distort the results of the study if they are not controlled for.

Do you want more practice?

If you want more training, read this study Depression treatmentsThis is a classic (and annoying) psychology experiments, and these studies on related to education Issues.

For each study, ask yourself:

  • What is under the researcher’s control? This is your independent variable.
  • What is being measured? This is your dependent variable.

To check your answers, write your hypothesis using the independent variable first. If your hypothesis shows that a cause-and-effect relationship makes sense, then you have correctly understood your variables. If the hypothesis does not make sense, give the study another look and try again!

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