Traits of Well Designed Experiment Ms Stocker 5

Traits of Well Designed Experiment Ms. Stocker

5 Characteristics of a Well Designed Experiment • • • Controlled Multiple Trials Large Samples Random Samples Good Records/Repeatable

Controlled • Only one variable is manipulated by the experimenter – Independent Variable • Ex) Amount of Water – Dependent Variable • Ex) Height of plant

Multiple Trials/Large Sample • Do the experiment more than once – Don’t just do a single test and say it proves your results • Have a lot of individuals to test – Have multiple subject per test condition • Ex) 50 plants get fertilizer and 50 do not get fertilizer

Random Sample • Make sure your test subjects are representative of the population you want to apply your results towards – You cannot test DAE kids then say the results apply to the whole county/state!

Good Records • Your experiment must be repeatable! • Write detailed directions how to conduct your experiment • Record all of your data accurately • The Village idiot must be able to get the same results you did!

Loose Ends • Experimental Group – Receives the experimental version of the independent variable • Ex) plant with fertilizer • Control Group – Receives the normal version of the independent variable • Ex) plant with no fertilizer • This group is used for comparison! • Constants – Any variables that could change the outcome of the experiment • Ex) temperature, amount of water, type of soil, length of sunlight exposure, amount of room to grow, etc…. .