2Testable Question What makes a question testable? It has variables It is something we can measure
3Variables There are 3 kinds of variables in an experiment… Manipulated variable:The thing you changeResponding variable:The thing you measureControlled variable:The things that stay the same
4Question: How much water flows through a faucet at different openings? Manipulated VariableWater faucet opening (closed, half open, fully open)Responding VariableAmount of water flowing measured in liters per minute
5Controlled variables The Faucet Water pressure, or how much the water is "pushing"
6Question: Does fertilizer make a plant grow bigger? Manipulated VariableAmount of fertilizer (measured in grams)Responding VariableGrowth of the plant measured by its heightGrowth of the plant measured by the number of leavesEtc.
7Controlled variables Same size pot for each plant Same type of plant in each potSame type and amount of soil in each potSame amount of water and lightMake measurements of growth for each plant at the same timeKeeping all of these things the same tells us that the only thing that could have caused differences in plant growth was the fertilizer.