Scientific Method A blueprint for experiment success.

How do YOU define science? (Think and discuss) A class wedged between gym and math? A dusty old textbook? Full of old Latin names no one can pronounce? Totally awesome? Part of being human? Something we encounter every day? A word we use to describe our ability to test ideas?

What is Science? 1. Studies the natural world. 2. Discovers nature's "rules" about how things work. 3. Discovers knowledge. Science excludes the supernatural- events or things that cannot be explained by nature. What do you mean we’re not science? Haven’t you seen our movies???

The Power of Observation Science begins with OBSERVATION. How observant are you? The scientific method is something all of us use all of the time -- being curious, asking questions, seeking answers – these are basic parts of the scientific method.

Inference, Hypothesis, Prediction An inference is a logical explanation for something based on prior experiences or knowledge. Example- Gray skies mean rain; sore throats lead to the flu A hypothesis is a possible explanation- it must be testable! Example) Exercising will help me lose weight. Prediction- A prediction is based on your hypothesis. Set up your prediction as an “IF, THEN” statement. Example) If I run 2 miles 5x a week for 6 weeks, then I will lose weight.

What is the scientific method? It is a simple method scientists use to conduct an investigation. It is a way to ask & answer scientific questions by asking questions & conducting experiments.

1. Question/Problem Ask a question about something observed. –Why? –How? –What? Question to be solved. Must be about something measurable.

2. Hypothesis Educated guess about how things work. Prediction Use If, then statements –If ____ [I do this], then _____ [this will happen] Focus on one variable only.

3. Experiment Tests your hypothesis. Is it accepted (right) or rejected (wrong) ? Change only one variable at a time In order for results to be valid, conduct several tests.

In order to get accurate results from your experiment, it must include two variables and a control group: Independent (manipulated) variable: what is changed during the experiment. Dependent (responding) variable: what you measure during the experiment. Control group- a group that is NOT experimented on; left alone to see what would happen without your manipulations so that you can compare results. Test your hypothesis. Experiment!

Independent vs. Dependent Variables Independent variable (or manipulated variable)- is what is changed. The dependent variable (or responding variable) is what you are measuring- The control group is what you left alone. Example- Example- A new mosquito repellent is tested before it hits the market. One arm is sprayed, the other arm is NOT sprayed. After 6 hours, mosquito bites are counted. In this case it is adding the mosquito repellent to your skin. the number of mosquito bites. The control group in this example is the arm that is NOT sprayed.

3. Experiment Record your data in a data table. –Numerical (quantitative) data organized in rows and columns –The specific independent variables are listed –The number of trials are listed –Blanks are left for the data (dependent variable) to be filled in

3. Experiment TrialVariable 1Variable 2Variable AVERAGE Title: Describing the Data

4. Data Analysis Reduce the data –Average (Mean) Graph –Graph the data to look for trends & relationships.

5. Conclusion Summary of your experiment. After your experiment, analyze your data to see if your hypothesis was accepted or rejected. If hypothesis is rejected, g ive possible reasons for the difference between your hypothesis and the experimental results.