We could measure blood pressure, or the amount of the stress hormone cortisol in their blood, or by using a paper and pencil measure such as a questionnaire that asks them how much stress they feel. The researchers then compare the scores of the exams between the two groups of classrooms. During the first three months of the academic year, they randomly select some 5th-grade classrooms to listen to Mozart during their lessons and exams. Other 5th grade classrooms will not listen to any music during their lessons and exams. Next, they randomly select university males to enter their testing facilities.
- Independent variables are a profound topic within research methodology.
- There are of course other types of variables, and different ways to manipulate them called “schedules of reinforcement,” but we won’t get into that too much here.
- Without experimental research, we would not be able to determine (with any confidence) how one variable may or may not impact another; we would not be able to determine cause and effect.
- After Galton’s pioneering work, the concept of the independent variable continued to evolve and grow.
- It is generally better to have more dependent variables than independent variables in a study because, with many independent variables, it can be difficult to determine which one caused a particular effect.
- Research variables are typically classified into several types based on their roles, characteristics, and nature of measurement.
Examples of Independent Variables
At the end of two months, the doctors measure the size of each patient’s tumor. If they can back up that claim with hard scientific data, that would be great for sales. This can provide very valuable information when studying just about any subject. Statology makes learning statistics easy by explaining topics in simple and straightforward ways. Our team of writers have over 40 years of experience in the fields of Machine Learning, AI and Statistics.
Independent variables can be varied and influence the dependent variable, giving different outcomes. In other words, dependent variables represent what happens as a result of the independent quantities. Researchers actively alter or manipulate them to achieve different conditions for comparison. This independent variable type represents groups that participants belong to.
Quiz – Variables
- In this study, the independent variable is meditation and the dependent variable is the amount of stress (however it is measured).
- He wants to randomly select 20 subjects from Richmond, Virginia, aged 20 to 30 years and weighing above 60 pounds.
- The independent variable was the airbag and the dependent variable was the amount of skull damage.
- This is also important so that the study can be replicated in the future using the same variables but applied in a different way.
- At the end of one year, the health of all participants is assessed, using blood pressure and cholesterol level as the key measurements.
They must consider other factors that might influence the relationship between the independent and dependent variables. These factors, known as confounding variables, should be controlled in the research design. For example, participant characteristics (age, gender, socioeconomic status) and environmental factors (time of day, geographic location, distractions) can serve as confounding variables. The independent variable is the variable that the researcher or experimenter manipulates to affect the dependent variable.
Researchers who grasp the details of these two fundamental pieces of the puzzle can more confidently and correctly navigate the complexities of experimental design, data analysis, and interpretation. This includes detailing how each outcome would be measured and quantified (for instance, the test scores, cumulative grade-point averages, and self-report surveys). The table compares the academic performance (test scores and GPA) and student engagement levels across the three different teaching methods being studied. Changing the plant growth rate affects the value of the amount of water. Changing the amount of water affects the value of the plant growth rate.
Independent Variables in Research
They refer to qualitative input and typically don’t involve numeric labels or categories. Categorical variables can be further categorized into nominal variables and ordinal variables. The following shows an example of an independent variable in a study that aims to determine the effect of sunlight on plant growth. Researchers conduct experiments to understand the cause-and-effect relationships between various entities. In such experiments, the entities whose values change are called variables.
This includes measurements, colors, sounds, presence or absence of an event, etc. The experiment is an incredibly valuable way to answer scientific questions regarding the cause and effect of certain variables. By manipulating the level of an independent variable and observing corresponding changes in a dependent variable, scientists can gain an understanding of many phenomena. By identifying the independent and dependent variable, researchers can understand the causal relationship between. They can conclude how independent variable can impact dependent variable. For example, in a study examining the impact of the teaching method on student academic achievement, the independent variable is the teaching method.
Here the dependent variable (and variable of most interest) was the annual mean sea level at a given location for which a series of yearly values were available. Use was made of a covariate consisting of yearly values of annual mean atmospheric pressure at sea level. The results showed that inclusion of the covariate allowed improved estimates of the trend against time to be obtained, compared to analyses which omitted the covariate. Scientists ask questions to find out more about the world, like ‘how can we get more energy from the sun? They must consider if there’s a directional relationship between them, like cause and effect. The researchers want to study the impact of learning styles on student performance.
Discrete variables
While the study participants are sleeping, their heart rates and amount of time spent in deep sleep are recorded with high-tech equipment. A company that specializes in essential oils wants to examine the effects of lavender on sleep quality. The researchers at the lab have their usual test volunteers sleep in individual rooms every night for one week. In doing so, the researchers can better determine the specific effect of the instructional method. For instance, they can determine whether the flipped classroom teaching model leads to higher test scores and engagement compared with the lecture-based method.
These are quantitative variables and can independent variable definition represent an infinite number of values within a given range. They are measurable quantities and can be further divided into smaller parts. Editage All Access is a subscription-based platform that unifies the best AI tools and services designed to speed up, simplify, and streamline every step of a researcher’s journey. In research, variables are any characteristics that can take on different values, such as height, age, temperature, or test scores.
Time and age are almost always the independent variable in an experiment. You can measure them, but you can’t control any factor to change them. In this highly unrealistic study, the independent variable is vitamins, and the dependent variable is health, as measured by blood pressure and cholesterol levels. An independent variable (IV) is what is manipulated in a scientific experiment to determine its effect on the dependent variable (DV). It’s important to decide what levels or values of the independent variable the researchers will manipulate and the range of values or measurements for the dependent element.
Variables
Imagine you hypothesize that people will wave back more to you when you are wearing casual clothes than to when you are wearing ragged clothes. In this case, the variables are the number of hand waves and clothing type. Since we will be counting the number of waves, this gives us a clue that the number of waves is the dependent variable. Since we think the type of clothing will affect how many waves are given, we can determine that the type of clothing is the independent variable.
Variables in experiments
A marketer changes the amount of money they spend on advertisements to see how it affects total sales. As the founder and leading proponent of psychoanalysis, Sigmund Freud was a central figure in 20th-century psychology. In this article, we’ll look at a number of his ideas about the human mind’s inner workings, and then survey both his work’s enduring influence and the criticism it has received. BachelorPrint is an online printing service specialised in printing and binding academic papers, theses, and dissertations. When you work with categorical variables like in this example, it is useful to visualize it in a bar chart. A quantitative variable is represented by actual amounts and a qualitative variable by categories or groups.
For example, a researcher might change the amount of water they provide to a certain plant to observe how it affects the growth rate of the plant. Imagine that participants who are helped with the door, on average, donate $10 to charity, and participants who are not helped with the door on average donate $5 to charity. It might be the case that being helped with the door (the independent variable) increases the likelihood someone will donate to charity (the dependent variable). You are studying the impact of different relaxation techniques on the stress level of participants with characteristics that indicate a high-stress level. The graph shows that as the number of members increases the expenditure also increases. Data visualization is the graphical representation of information by using charts, graphs, and maps.