Psychology Terminology: Dependent Variable

As previously discussed, an experiment tries to establish a causal link between two variables. One we call the dependent variable and the other is referred to as the Independent variable. We also discussed something called a confounding variable which is a factor that can mess with the results of the experiment by changing the nature of the relationship between two variables.

This post will summarise what is meant by a dependent variable.

But let's start by asking what is the variable dependent on?

Well whatever the variable considered, we call it dependent as it depends on what happens with the independent variable.

Let's imagine Bandura's experiment establishing a causal link between observed violence and the violence demonstrated by the participants.

In this scenario the dependent variable is the 'amount of violence demonstrated by the children', this variable depended on a set of independent variables which could be changed by the researchers. An example of one of these independent variables was whether a child observed violence as in the control group when they were not.

Thus an independent variable is ideally free from other factors and can be manipulated by researchers to see whether there's a causal link between the independent variable and the dependent variable.

Let's play with this idea and imagine an experiment in which we have three light bulbs and a switch. We want to establish a causal link between one of the lightbulbs and the switch. When we flick the switch a lightbulb flickers to life. In absence of any other factors which might be activating the light, we may conclude that the flicking of the switch causes the bulb to light.

What do you think our independent and dependent variables are?

Well, the dependent variable is whether or not our lightbulb is illuminated. This is dependent on whether we flick the switch or not.

But what possible confounding variables are there?

Well let's imagine that the circuit linking the lightbulb also includes an internal clock, and periodically the lightbulb responds to the clock by lighting. In this case, if we're not careful our flicking of the switch might just happen to coincide with the lightbulb lighting due to the switch and thus we would be unable to conclude that the lightbulb is responding to the switch.