1. Designing an Experiment Always ask yourself: Is this information worthy of my time? Barbara B. Bittner PFHS 2011

2. What is the impact of mouse self-esteem? (McCoy, 2011)

3. Step 1Ask a Question! • Ask a question. • Use your powers of observation of the world around you • Pick something you are truly interested in, you will be working with it for a long time • This must be a question to which the answer is not already well known • Make it a question you cannot find the answer to by simply doing a decent internet search

4. Step 1: The Question For a question to be answered scientifically, it must be clear and testable, and the phenomenon that you question must be measurable and controllable. For instance, you could not ask "Is hydroponics superior to soil for growing plants?" because whether something is "superior" is a matter of opinion. (S. H. A. R. P., 2001)

5. Step 2: Form a Hypothesis • Best format: If (the independent variable is manipulated) then (the dependant variable will). • The hypothesis or prediction must have the potential to be proved wrong. The hypothesis will never be proved right—but it can be accepted as correct. Example: If the student pays attention to the presentation and takes notes, then the project created will follow the correct format.

6. Hypothesis vs. Null Hypothesis • If/ then statement. Prediction that change will happen due to a change of some aspect of the independent variable. • If/then statement Prediction that the outcome of the experiment will not be influenced by the change in the independent variable. NULL HYPOTHESIS HYPOTHESIS

7. Step 3: Determine the Variables Controlled Variables Independent Variables Dependent Variables What the scientist changes with each trial. The goal is to have only 1 IV. When more than 1 IV is introduced it maybe impossible to determine which one really caused the DV to change. What the scientist measures. There is usually more than one level of the DV. An experiment can have several dependent variables because variations in the independent variable can have many different effects. (S. H. A. R. P., 2001) These are the conditions that must not be allowed to change between trials. If these change, they become independent variables and the intent of the experiment may be lost.

8. Step 4: Design the Procedure • The procedure is the exact steps preformed by the scientist. • The procedure may change as you find a better or more accurate way to work. Be sure you make note of all changes in the procedure and include them in the final procedure.

9. Step 4: Design the Procedure • Level of Treatment An important part of the procedure is the level of treatment. This is the different levels of the independent variable. Example: Different concentrations of fertilizer on tomato plants would be different levels of treatment .

10. Step 4: Design the Procedure • Replication This is the number of times the scientists repeats the procedure. It is important that the results be reliable. Reliability can only be confirmed if consistent data is obtained in successive trials. Replication removes the likelihood that the dependent variable changed due to random chance.

11. Step 4: Design the Procedure • Control Group Be careful not to confuse the control group with the controlled variables. The control group is a population of individuals(group) that are not treated and therefore indicate how the population being tested would change over time under normal circumstances. The controlled variables are the variables that never change in any group.

12. Works Cited • McCoy, G. (2011, January 20). Cartoon Parade. The Washington Post , p. 15. • S. H. A. R. P. (2001). Lesson Two: Design and Experiment. Retrieved January 25, 2011, from • ORACLE: Thinkquest: http://library.thinkquest.org/C0110342/lessonplan/lesson2.html