Testable Questions

1. Testable Questions Rules for Creating Them!

2. A good scientist asks many questions; however, only those questions that are testable using science experiments are useful to a scientist.

3. Read the following questions and decide if they are testable. 1. Do cats eat more in the daytime or nighttime? 2. On which continents can rainforests be found? 3. What would happen to a student if he/she didn’t sleep for 48 hours? 4. Which brand of dish soap makes the most bubbles: Dawn, Ivory, or Palmolive? 5. What is the best brand of breakfast cereal? 6. Does temperature affect the life of a battery? 7. Why is eating junk food bad for your health?

4. Testable questions are always about changing one thing to see what the effect is on another thing. Now that you can identify a testable question…let’s see how to actually WRITE a testable question!

5. Sample Testable Question Does changing the height of the ramp affect the speed of a car going down the ramp?

6. In a scientific experiment, these two blanks have special names: variables – things that can change. Testable Question Formats • Does changing _______ affect _______? • How does changing _____ affect _____? • If I change ______, will it affect ______?

7. Testable Questions have two parts: • An independent variable • A dependent variable

8. Let’s compare the two types of variables… • Independent Variable • CHANGEdby you on purpose • What you have CONTROL over • What you as a scientist MANIPULATE • There can be ONLY ONE • Dependent Variable • What is measured in the experiment • changes because of what you changed on purpose

9. Testable Question Formats • Does changing _______ affect _______? • How does changing _____ affect _____? • If I change ______ will it affect ______? independent variable dependent variable independent variable dependent variable dependent variable independent variable

10. Example: • Does changing the height of the ramp affect the speed of the car going down the ramp? • Identify the IV and DV in this question.

11. Practice • Does the temperature of water affect the time it takes a sugar cube to dissolve? Identify the INDEPENDENT variable _________________________ Identify the DEPENDENT variable _________________________

12. HypothesisWriting No it’s not JUST an educated guess! 

13. What you need to know… • A hypothesis is an “educated guess” about how things work. • What does “educated” mean? • You have to be “educated” on a topic before you can “guess” about it! ….DUH!!!! • Most of the time a hypothesis is written like this: "If _____[I do this – independent variable], then _____[this – dependent variable] will happen." (Fill in the blanks with the appropriate information from your own experiment.)

14. Hypothesis • "If I open the faucet [faucet opening size is the independent variable], then it will increase the flow of water [flow of water is the dependent variable].” • A hypothesis expresses your independent variableand your dependent variable.

15. EXAMPLES • "If I put fenders on a bicycle [having fenders is the independent variable], then they will keep the rider dry when riding through puddles [the dependent variable is how much water splashes on the rider]."

16. EXAMPLES • If a plant receives fertilizer [having fertilizer is the independent variable], then it will grow to be bigger than a plant that does not receive fertilizer [plant size is the dependent variable]."

17. EXAMPLES • "Raising the temperature of a cup of water [temperature is the independent variable] will increase the amount of sugar that dissolves [the amount of sugar is the dependent variable]."

18. CHECKLIST • Start thinking about the hypothesis you wrote at the beginning of class. Use this checklist to see if you wrote a testable statement.

19. Now you try!  What effect does high temperature have on radish germination? • Hypothesis- • Independent variable: • Dependent variable: What effect does studying with music have on student test scores? • Hypothesis- • Independent variable: • Dependent variable:

20. Let’s practice writing a few… Does carbon dioxide in the atmosphere cause the atmosphere to warm? Ask yourself: 1. Which variable can I change ON PURPOSE (IV)? 2. What is going to change because of what I changed (DV)? Write the testable question: Does changing the amount of carbon dioxide affect atmospheric temperatures?

21. Is achievement in school higher when students are tested frequently? Ask yourself: 1. Which variable can I change ON PURPOSE (IV)? 2. What is going to change because of what I changed (DV)? Write the testable question: How does frequency of testing affect student achievement?

22. Do crickets chirp faster in warmer temperatures or cooler temperatures? Ask yourself: 1. Which variable can I change ON PURPOSE (IV)? 2. What is going to change because of what I changed (DV)? Write the testable question: How does the change in temperature affect the speed of a cricket’s chirp?

23. Now you try!  What effect does food color have on the amount of food fish eat? • Hypothesis- • Independent variable: • Dependent variable: What effect does light have on plant growth? • Hypothesis- • Independent variable: • Dependent variable:

24. Now you practice on your own • Hypothesis Practice: all by your lonesome 