Regardless of what investigation you are doing in science there are some fundamentals that must be understood. These are the things that can be changed, which are referred to as VARIABLES.
There are three types of variable that need to be identified; independent, dependent and control. The independent variable is what is changed, the dependent variables are what will be measured and the control variables are all the aspects of the investigation that need to be kept the same so as to ensure a fair test.
The significance of identifying these early on in the investigation allow for simple rules to be followed when making the results table, drawing graphs and writing conclusions. The independent variable always goes in the first column of the table and usually goes along the x-axis. The dependent variable always goes in the second column of the table and usually goes on the y-axis. To write conclusions you then simply say as "the independent variable" increases "the dependent variable" increases/decreases.
Once this skill has been learned, it can be transferred to any science investigation and helps to structure thoughts when answering questions on core practicals that will feature in the new style GCSE exam questions.