# Test relationship between independent dependent variable

### Dependent and independent variables review (article) | Khan Academy

We go over the definitions of independent and dependent variables so you There are two key variables in every experiment: the independent variable . the relationship between the dependent and independent variables. To understand the concept of independent and dependent variables, one that measures the affect of the independent variable(s) on the test units. Usually when one is looking for a relationship between two things, one is. One Independent Variable (With Two Levels) and One Dependent Variable An example of a t test research question is “Is there a significant difference.

To be clear though, for a science fair, it is usually wise to have only one independent variable at a time. If you are new to doing science projects and want to know the effect of changing multiple variables, do multiple tests where you focus on one independent variable at a time.

The dependent variables are the things that the scientist focuses his or her observations on to see how they respond to the change made to the independent variable. In our dog example, the dependent variable is how much the dogs eat. This is what we are observing and measuring.

## Variables in Your Science Fair Project

It is called the "dependent" variable because we are trying to figure out whether its value depends on the value of the independent variable. If there is a direct link between the two types of variables independent and dependent then you may be uncovering a cause and effect relationship.

**Correlation in SPSS**

The number of dependent variables in an experiment varies, but there can be more than one. Experiments also have controlled variables. Controlled variables are quantities that a scientist wants to remain constant, and she or he must observe them as carefully as the dependent variables.

- The Difference Between Independent and Dependent Variables

For example, in the dog experiment example, you would need to control how hungry the dogs are at the start of the experiment, the type of food you are feeding them, and whether the food was a type that they liked. If you did not, then other explanations could be given for differences you observe in how much they eat. For instance, maybe the little dog eats more because it is hungrier that day, maybe the big dog does not like the dog food offered, or maybe all dogs will eat more wet dog food than dry dog food.

So, you should keep all the other variables the same you control them so that you can see only the effect of the one variable the independent variable that you are trying to test. Similar to our example, most experiments have more than one controlled variable. Some people refer to controlled variables as "constant variables.

Weight or mass is an example of a variable that is very easy to measure. However, imagine trying to do an experiment where one of the variables is love. It is important to note that there can be more than one dependent variable.

## Dependent and independent variables review

Width or other factors to measure health such as could be measured as well. All of these variables are dependent upon the independent variable the vitamin substance.

Outside of some advanced forms of research, you cannot have more than one independent variable for a valid experiment. In order to receive accurate results, the researcher needs to know the one factor that is causing the results of the experiment. The control variables are variables that must be held constant or neutralized from the beginning to the end of the experiment for the results to be reliable.

### Variables in Your Science Fair Project

Everything except the independent and dependent variables need to stay the same throughout the experiment. Some control variables would be the amount of liquid given to the plant, the tools used, location, soil quality, sunlight, and temperature.

Independent and Dependent Variables in Math You probably remember being introduced to variables during an introductory Algebra lesson. In math, variables are the x and y values in an equation or graph. The term function is often used when using independent and dependent variables in math. Functions are examined algebraically or graphically by either looking at equations or graphs.

The independent variable is often designated by x. The dependent variable is often designated by y. We say y is a function of x. This means y depends on or is determined by x. This means that mathematically y depends on x. If we know the value of x, then we can find the value of y. The final solution of the equation y depends on the value of x or the independent variable which can be changed. The dependent variable is y because it depends upon the value chosen for x.

The dependent variable is usually isolated on one side of the equation.

Graphing Independent and Dependent Variables Throughout the practice of both math and science, dependent and independent variables can be plotted on the x and y axes of a graph. A graph shows a clear relationship between the x and y variables. A simple and effective way to represent data using an independent and dependent variable would be a two-dimensional graph.

When graphing information, traditionally the independent variable is placed on the y axis and the dependent variable is placed on the x axis.