The Scientific Method

The Scientific Method The scientific method is an organized way to solve a problem through experimentation & observation.

1. State the Problem Form a question about a specific event or reaction; often this question is based on observations Example: Will your stomach explode if you eat Pop Rocks and drink soda?

2. Collect Information Research all aspects of the problem—observations, research, etc. Example: What can you find out about Pop rocks, the stomach, soda, or digesting candy and/or soda? What type of information do we need to know about Pop Rocks and soda? What ingredient do the two products have in common? So, where is our urban myth coming from? The belief is that when the two products are mixed, the amount of carbon dioxide created in the stomach is so large that the stomach explodes. Based on that information, how could we change our problem (testable question)? http://en.wikipedia.org/wiki/Pop_Rocks http://www.drpepper.com/ http://en.wikipedia.org/wiki/Stomach http://www.internethealthlibrary.com/DietandLifestyle/Food_combining.htm

3. Form a hypothesis Make a suggested solution to the problem. A hypothesis is always written in an “if . . then . . .” format. Example: If you eat a pack of Pop Rocks and drink soda, then your stomach will explode because of the amount of carbon dioxide produced

4. Design an Experiment Devise a way to test your hypothesis—write a step-by-step procedure Create a CONTROLLED experiment. You have a headache and want to determine what will alleviate the pain fastest. You decide to take an aspirin, put a cold cloth on your forehead, and to take a nap. Which technique was better at alleviating the pain? Impossible to tell because you did all three at the same time—have to test one ting (or variable) at a time.

A controlled experiment MUST have 2 groups: CONTROL GROUP: all conditions of a “normal” situation EXPERIMENTAL GROUP: only the condition that you are testing for is changed Twinkie Experiment: What ate the effects of eating Twinkies 3 meals a day, everyday, for 3 months? I find a 14 year old male and feed him Twinkies 3 meals a day, everyday, for 3 months. At the end of three months the boy’s shoe size has gone up ½ size. Did the Twinkies cause this? Unknown—we don’t have a “regular kid” to compare this to. A control is a “normal” group. Need second subject (person to test) eating a regular diet to compare to. What needs to be the same (constants) about our subjects? (Height, lifestyle, mental capacity, gender, age, etc) Also need to test subjects before AND after experiment to observe differences over time (body measurements, physical and mental tests, etc). ONLY 1 condition is changed! Constants: everything other than the condition being tested is kept the same to be fair

Establish the variables for your experiment. INDEPENDENT (manipulating) VARIABLE: the variable that is changed (X axis for graphing) DEPENDENT (responding) VARIABLE: the change caused by changing the independent variable; the variable being measured (Y axis for graphing) The independent variable is also called the manipulating variable

Pop Rocks Experiment Control Group –Soda without Pop Rocks Experimental Group -Pop Rocks and soda

Pop Rocks Experiment INDEPENDENT VARIABLE: Use of Pop Rocks Amount of carbon dioxide in stomach

5. Collect & Analyze Data Run the experiment & record the data in a chart or graph

There are two types of data: QUANTITATIVE: numerical data, deals with specific quantities, usually in the form of a graph or chart QUALITATIVE: descriptive data, describes how something looks, smells, sounds, or feels; deals with qualities

QUALITATIVE EXAMPLE : QUANITATIVE EXAMPLE: Placing Pop Rocks in soda makes popping sounds QUANITATIVE EXAMPLE: Amount of gas produced by Pop Rocks= ______ Amount of gas produced by Soda= _________ Amount of gas produced by Pop Rocks and soda=______ Conduct experiment by opening soda and placing Pop Rocks in balloon, pull balloon over top of soda, empty Pop Rocks into soda (the control will not contain Pop Rocks).

6. Draw Conclusions Determine from the data collected supports your hypothesis EXAMPLE: Eating Pop Rocks and drinking soda does not cause your stomach to explode because the combination does not produce enough carbon dioxide What happens if your hypothesis turns out to be wrong (doesn’t support the hypothesis)? Nothing. In science its okay to be wrong. This may lead to another experiment

Repeating the Experiment Scientists repeat experiments to see if they get the same findings and results. Verification— checking things out to make sure everything was valid and will happen again and again.

Sharing Their Findings Scientists share their findings to learn from each other and often use someone else’s experiences to help them with what they are studying or doing.

Is there one right way to follow the scientific method? http://www.kimmelhome.com/Science_Skills/index.html

They Might Be Giants “Put It to the Test”