DETERMINING VARIABLES

To make our experiment a fair test, we needed variables. There are several variables that will affect the water quality of the river.To find out the causes of pollution and effect on the river life and check the pollution level in Kallang River and Jurong Lake.We need different results of the water quality through various physical factors: water temperature, pH level, dissolved oxygen, turbidity, salinity. These factors are the dependent variables which means they are the variables that are measured.

The independent variable is which river(Kallang River/Jurong Lake) we would be investigating. 

But, there are other variables that will affect the outcome of the experiment. These are the control variables that are to be kept constant. Some control variables are the amount of water that was taken out of each river, duration of measurements.