What are independent, dependent variables?
The DV is what is being measured. It is the effect in other words.
The IV is what is being manipulated by the researcher. In other words, it is the factor that changes in the different conditions of the experiment.
The aim of an experiment, therefore, is usually to investigate the effect of the IV on the DV.
Take this example: Mr Dixon wants to find out if fertilizer actually works for making his garden grown. He therefore decides to use fertilizer on half of his garden and none on the other half. He will then see which side of the garden grows better.
In this gardening experiment the aim is to determine if using fertilizer actually has an impact on garden growth. The IV would be the use of fertilizer, because I’m the one who has changed this variable by using it on only half of the garden. The DV is the amount of growth in the garden because that is what I’m measuring to see if the IV actually had an effect.
I’ll be using my gardening example throughout this unit on experimental research.
Travis Dixon is an IB Psychology teacher, author, workshop leader, examiner and IA moderator.