Preparing for the Science Fair Scientific Method Preparing for the Science Fair

Testable Questions Can be answered through hands-on investigations. They are NOT opinion questions or questions that can be answered by doing research in a book or on the internet. You must be able to measure the results in some way for it to be considered a testable question.

3 types of testable questions 1. The effect question What is the effect of sunlight on the growth of plants? 2. The how does affect question How does the color of light affect the growth of plants? 3. The Which/What and verb question Which/what paper towel is most absorbent?

Let’s practice identifying testable questions… What types of apples grow in Michigan? Not a testable question. It can not be tested through an experiment. You can answer this question with research on the internet or in a book.

How does talking to a plant affect a plants height? Testable question. It is a How Does Affect question.

Which pill design- tablet, caplet, or capsule- will dissolve faster? Testable question. It is a Which/What verb question.

Which planet is the most interesting one to study? Not a testable question. It is an opinion and can not be proved in an experiment.

How does stirring affect the rate that salt dissolves in water? This is a testable question. It is a How Does affect question.

Writing a Hypothesis A hypothesis is a special kind of prediction that forecasts (predicts) how changing one part of an experiment will affect the results. It is NOT a guess. It is an informed and well-thought out prediction that requires background information. You can also think of it as a cause-effect statement.

A hypothesis is best written in the “If ______________, then _____________.” format. After the “if” is the part the scientist will change on purpose. After the “then” is the result of the change. Q: How does the amount of daylight affect how many eggs laid by a chicken? H: If the amount of daylight increases, then the chickens will lay more eggs.

Q: How does the amount of leaves on a tree affect how many birds will build nests in it? H: If a tree has more leaves in it, then birds will be more likely to build a nest in it.

Q: How does the acid level of a lake affect how many fish live there? H: If a lake has a higher level of acid in it, then fewer fish will live there.

Q: How does the acid level of a lake affect how many fish live there? H: If a lake has a higher level of acid in it, then fewer fish will live there.

Variables Variables are conditions that could affect the outcome of an experiment. Think about all of the different things that might affect how well a student does on a test. -- their amount of sleep – how long they studied –if they’re feeling well – how well they paid attention in class All of those things are variables- they affect how well the student will perform.

What variables can affect the number of fish in a lake? Temperature of the water The quality of the water- pollutants? What the lake is used for

Discuss with your table group. What variables can affect the taste of soda?

There are 3 types of variables. The independent variable is what you change on purpose in an experiment. Usually there is only one independent variable in an experiment. Ask yourself “What did I change?” The dependent variable is what you measure in an experiment. Ask yourself “What do I observe?” The controlled variable is the condition that remains the same in an experiment. Ask yourself “What did I keep the same?”

Q: How does the size of the faucet opening affect the amount of water that flows out of it? Independent Variable (What I change) Dependent Variable (What I observe) Controlled Variable (What I keep the same) Water faucet opening (closed, half open, fully open) The amount of water flowing, measured in cups per minute The faucet

Q: How does the temperature of water affect the rate that sugar dissolves? Independent Variable (What I change) Dependent Variable (What I observe) Controlled Variable (What I keep the same) The temperature of the water in degrees Fahrenheit. The amount of sugar that dissolves measured in grams. Stirring and the type of sugar.