Types of Variables in Research & Statistics Examples

Types of Variables in Research & Statistics Examples

In quantitative research, independent variables are usually measured numerically and manipulated to understand their impact on the dependent variable. In qualitative research, independent variables can be qualitative in nature, such as individual experiences, cultural factors, or social contexts, influencing the phenomenon of interest. The independent variable is the factor the researcher changes or controls in an experiment. It is called independent because it does not depend on any other variable. The independent variable may be called the “controlled variable” because it is the one that is changed or controlled. This is different from the “control variable,” which is variable that is held constant so it won’t influence the outcome of the experiment.

In accounting, an independent variable is ideally a factor that causes a change in the total amount of the dependent variable. In other words, an independent variable should be something that drives a mixed cost to increase or decrease. They discovered that by manipulating one factor (the independent variable), they could observe changes in another (the dependent variable), leading to groundbreaking insights and discoveries. After Galton’s pioneering work, the concept of the independent variable continued to evolve and grow.

It helps scientists and researchers ask critical questions, test their ideas, and find answers. Without independent variables, we wouldn’t have many of the advancements and understandings that we take for granted today. Of the two, it is always the dependent variable whose variation is being studied, by altering inputs, also known as regressors in a statistical context. In an experiment, any variable that can be attributed a value without attributing a value to any other variable is called an independent variable. Models and experiments test the effects that the independent variables have on the dependent variables. Sometimes, even if their influence is not of direct interest, independent variables may be included for other reasons, such as to account for their potential confounding effect.

  • Imagine if our chef used a different type of broth each time he experimented with spices—the results would be all over the place!
  • It is often used when the issue you’re studying is new, or the data collection process is challenging in some way.
  • The independent variable is the amount of light and the moth’s reaction is the dependent variable.
  • A regression analysis that supports your expectations strengthens your claim of construct validity.
  • Researchers must ensure that participants provide informed consent and that their privacy and confidentiality are respected.

As such, a snowball sample is not representative of the target population and is usually a better fit for qualitative research. When a test has strong face validity, anyone would agree that the test’s questions appear to measure what they are intended to measure. If the test fails to include parts of the construct, or irrelevant parts are included, the validity of the instrument is threatened, which brings your results into question. Yes, but including more than one of either type requires multiple research questions. If you want to know more about statistics, methodology, or research bias, make sure to check out some of our other articles with explanations and examples.

Examples of independent variable in a Sentence

If participants know whether they are in a control or treatment group, they may adjust their behavior in ways that affect the outcome that researchers are trying to measure. If the people administering the treatment are aware of group assignment, they may treat participants differently and thus directly or indirectly influence the final results. Simple random sampling is a type of probability sampling in which the researcher randomly selects a subset of participants from a population. Data is then collected from as large a percentage as possible of this random subset.

The independent variable is the variable that is controlled or changed in a scientific experiment to test its effect on the dependent variable. It doesn’t depend on another variable and isn’t changed by any factors an experimenter is trying to measure. The independent variable is denoted by the letter x in an experiment or graph. To ensure the internal validity of your research, you must consider the impact of confounding variables. If you fail to account for them, you might over- or underestimate the causal relationship between your independent and dependent variables, or even find a causal relationship where none exists. An independent variable is the variable you manipulate, control, or vary in an experimental study to explore its effects.

  • Mistaking correlation for causation is a common error and can lead to false cause fallacy.
  • It helps researchers create vaccines, understand social behaviors, explore ecological systems, and even develop new technologies.
  • The hours of sleep would be the independent variable while the test scores would be dependent variable.

The world is brimming with questions waiting to be answered and mysteries waiting to be solved. For example, something might be either present or not present during an experiment. Experiments are usually designed to find out what effect one variable has on another – in our example, the effect of salt addition on plant growth.

Science Fair Project Variables Checklist

However, in stratified sampling, you select some units of all groups and include them in your sample. In this way, both methods can ensure that your sample is representative of the target population. Unlike probability sampling (which involves some form of random selection), the initial individuals selected to be studied are the ones who recruit new participants. Independent and dependent variables are generally used in experimental and quasi-experimental research.

Identifying Independent Variables in Everyday Scenarios

The directionality problem is when two variables correlate and might actually have a causal relationship, but it’s impossible to conclude which variable causes changes in the other. The third variable problem means that a confounding variable affects both variables to make them seem causally related when they are not. It defines your overall approach and determines how you will collect and analyze data. Common types of qualitative design include case study, ethnography, and grounded theory designs. But multistage sampling may not lead to a representative sample, and larger samples are needed for multistage samples to achieve the statistical properties of simple random samples. Scientists and researchers must always adhere to a certain code of conduct when collecting data from others.


It’s like a chef experimenting with different spices to see how each one alters the taste of the soup. The independent variable is the catalyst, the initial spark that sets the wheels of research in motion. The independent variable plays a starring role in experiments, helping us learn about everything from the smallest particles to the vastness of space. It helps researchers create vaccines, understand social behaviors, explore ecological systems, and even develop new technologies. In this article, we’ll explore the fascinating world of independent variables, journey through their history, examine theories, and look at a variety of examples from different fields. To ensure cause and effect are established, it is important that we identify exactly how the independent and dependent variables will be measured; this is known as operationalizing the variables.


Scientists try to figure out how the natural world works.To do this they use experiments to search for cause and effect relationships. Cause and effect relationships explain why things happen and allow you to reliably predict the outcomes of an action. Scientists use the scientific method to design an experiment so that they can observe or measure if changes to one thing cause something else to vary in a repeatable way.

You have to be the one to change the popcorn and fertilizer brands in Experiments 1 and 2, and the ocean temperature in Experiment 3 cannot be significantly changed by other factors. Changes to each of these independent variables cause the dependent variables to change in the experiments. Both the independent variable and dependent variable are examined in an experiment using the scientific method, so it’s important to know what they are and how to use them. Here are the definitions for independent and dependent variables, examples of each variable, and the explanation for how to graph them.

Researchers often model control variable data along with independent and dependent variable data in regression analyses and ANCOVAs. That way, you can isolate the control variable’s effects from the relationship between the variables of interest. Exploratory research is a methodology approach that explores research questions that have not previously been studied in depth. It is often used when the issue you’re studying is new, or the data collection process is challenging in some way. To ensure the internal validity of an experiment, you should only change one independent variable at a time. Here are some examples of research questions and corresponding independent and dependent variables.

Anonymity means you don’t know who the participants are, while confidentiality means you know who they are but remove identifying information from your research report. In this process, you review, analyze, detect, modify, or remove “dirty” data to make your dataset “clean.” Data cleaning is also called data cleansing or data scrubbing. These data might be missing values, outliers, duplicate values, incorrectly formatted, or irrelevant.

Table of contents

Stratified sampling and quota sampling both involve dividing the population into subgroups and selecting units from each subgroup. The purpose in both cases is to select a representative sample and/or to allow comparisons between subgroups. This means that you cannot use inferential statistics and make generalizations—often the goal of quantitative research.

Now that we’re acquainted with the basic concepts and have the tools to identify independent variables, let’s dive into the fascinating ocean of theories and frameworks. As Galton delved into the world of statistical theories, the concept of independent variables started taking shape. In psychology, a dependent variable represents the outcome or results and can change based on the manipulations of the independent variable. Essentially, current ratio calculator working capital ratio it’s the presumed effect in a cause-and-effect relationship being studied. By changing the independent variable and holding other factors constant, psychologists aim to determine if it causes a change in another variable, called the dependent variable. In a well-designed experimental study, the independent variable is the only important difference between the experimental (e.g., treatment) and control (e.g., placebo) groups.

Deixe um comentário

O seu endereço de e-mail não será publicado. Campos obrigatórios são marcados com *

Travelers' Map is loading...
If you see this after your page is loaded completely, leafletJS files are missing.