The Scientific Method September 11, 2012 Mr. Alvarez

The Survivor’s Dilemma  Do Now: You are shipwrecked on a dessert island with no contact to anyone. You are thirsty, but surrounded by salt-water. You remember the captain had said that one of the containers on the ship contained drinking water, but the other contained a toxic substance. In the two beakers in front of the class are those two indistinguishable liquids. One is safe to drink (pure, clean water) and the other liquid is an unknown and toxic substance. Answer the following questions: 1.Make general observations about both the beaker on the left, and the beaker on the right 2.What could you do to determine which liquid is safe to drink? 3.Which one would you drink?

The Scientific Method

 Scientific Method- A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis and stating conclusions  Steps to the Scientific Method may vary  Research often leads to new problems and new hypothesis  Variable- a factor that changes in an experiment in order to test a hypothesis

The Scientific Method 1.Observe: Observe anything in nature 2.Formulate a question: What do you want to know? 3.Research and collect data: What is already known about your question? 4.Form a hypothesis: Propose an answer to your question based on observations, research and data

The Scientific Method cont. 5.Test the Hypothesis: Set up an experiment to test the validity to your hypothesis 6.Record and Analyze Results: Record observations in journal or lab notebook and study the outcome 7.Draw a conclusion: Did the results support your hypothesis? If not, modify the hypothesis based on observations

Importance of a Controlled Experiment  Controlled Experiment-an experiment in which only one variable is changed at a time  Control-a person, group, event, etc., that is used as a constant and unchanging standard of comparison in scientific experimentation.

Examples of Controls  If you want to know how speed affects gas mileage, then speed is the only variable that should change. The car, tires, road, wind speed need to stay the same—be controlled. They are control variables.  In Medicine, the placebo effect.

Bikini Bottom Experiments 1)Flower Power SpongeBob Squarepants loves to garden and wants to grow lots of pink flowers for his pal Sandy. He bought a special Flower Power fertilizer to see if it will help plants produce more flowers. He plants two plants of the same size in separate containers with the same amount of potting soil. He places one plant in a sunny window and waters it every day with fertilized water. He places the other plant on a shelf in a closet and waters it with plain water every other day What did SpongeBob do wrong in this experiment? Explain?