~ CONTROL vs EXPERIMENTAL ~

WHAT IS THE DIFFERENCE BETWEEN CONTROL & EXPERIMENTAL SET-UPS?


CONTROL ( Bare minimum): This is the set-up without the test. 

EXPERIMENTAL (The testing setup): Exactly the same set-up as the CONTROL, except you INCLUDE  the 1 THING that you want to measure factored in.


Example 1: I wanted to test how the intensity of light will affect the rate of evaporation. 

Thus I will have 2 set-ups; Control + Experimental 

 The 2 tanks should be at the exact same temp, same size, same amount of water,etc. However, the EXPERIMENTAL would have light, as I am testing the intensity of light. 

 Since every other aspect of the experiment was the same for the two tanks except for the light, my CONTROL would be the tank WITHOUT LIGHT.

 With this set-up, then I'll be able to say how the intensity of light will affect the rate of evaporation. 

Example 2: I wanted to test how the presence of cadmium affects a mussel's heart rate. 

 I would have at least two tanks, one for the control and one for the experimental. The tanks should be at the exact same temp, same size, same amount of water, same amount of sunlight, and same number of organisms in each tank.

 However, the EXPERIMENTAL would have whatever concentration of cadmium I was testing. Then, I'd apply the heart rate monitors (usually a sensor you attach to the mussels, above the hearts) and test at exactly the same time for the exactly the same amount of time. 

 Since every other aspect of the experiment was the same for the two tanks except for the cadmium(Not Present in CONTROL), I'd be able to say something about how the cadmium affects heart rates. 



Example 3: I wanted to rate the effect of caffeine have on plants. 

 An EXPERIMENTAL set-up would have several plants that you would water using diluted coffee or tea. 

 The CONTROL would be the plant you would use water only on. This way if they all die, you know there was something wrong with the plants, not the experiment.

EXAMPLE