Methods of Scientists ISN page 5

Experimental Design Observe Question/Problem Research Hypothesize (If/Then) Experiment Analyze Conclude HAVE STUDENTS WRITE DOWN EACH OF THESE IN THEIR OWN WORDS.

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2. State the Problem/Question 1. Observe 2. State the Problem/Question - What do you want to know?

3. Gather Information 4. Form a Hypothesis Research the problem It should also be an “if/then” statement For example: If leaf color change (dependent variable) is related to temperature, (independent variable) then exposing plants to cooler temperatures will cause leaves to change color.

6. Record and Analyze Data 5. Test the Hypothesis At least 3 times More trials=better data 6. Record and Analyze Data Create a chart/graph to organize data Look for a trend

7. State the Conclusion 8. Repeat the Work Review any problems (bias) that you may have had The conclusion should be stated as “results support” or “fail to support” 8. Repeat the Work Many trials are needed before a hypothesis can be accepted

Variables and Controls Variable- anything that changes Independent Variable- the factor that the experimenter (you) changes. It is unaffected by any other variable. Dependent Variable- variable that changes because the independent variable changed Control- the factor in the experiment that does not change (you won’t always have this)

Hypothesis Hypothesis: A suggested explanation for an observation that is followed with experimentation A successfully tested hypothesis can become a scientific theory

Question to answer on your own: Brooke designs an experiment to determine if temperature has an effect on the amount of sugar that can be discovered in a glass of tea. Her materials for conducting her experiment include beakers, tea bags, sugar, water, and stirring rods. 1. Identify the independent and dependent variables. Why? 2. What should she keep constant? Why?