1. Designing an Experiment

2. Hypothesis • An educated guess about the effect a change will have on an outcome • Stated as an, “If _____, then_____.” statement • Cannot be written w/o understanding experiment design.

3. Repeated Trials • Running a test multiple times so that you can determine what is valuable data versus fluke (experimental error)

4. Independent Variable • The purposeful change • What did you modify, alter, or vary/change in your experiment?

5. Dependent Variable • The response to the change • What was effected by the independent variable?

6. Constructing a Hypothesis IF the independent variable is describe how you changed, THEN the dependent variable will describe the effect.

7. How will I know if the hypothesis is correct? • If the experiment’s results are the same as your hypothesis then we say the hypothesis is “supported” by the data: your hypothesis was right! • Not supported means wrong

8. Variable • ALL factors that change or could change in an experiment • Independent (manipulated): is the one you change knowingly • Dependent (responding): is the one that was changed by the independent

9. Levels of Independent Variables • Sometimes you have more than one amount of the same variable • The number of scoops of CaCl2 (0,1,2, or 3) created different levels of the variable

10. Constants • Factors that remained unchanged or the same throughout the experiment • Amount of water • Time to dissolve • Stirring

11. Control • Trials that are run without the independent variable to detect or measure the influence of unanticipated factors • Temperature gain from room or stirring

12. Experimental Design Diagram • An organized way to summarize your experiment. • It allows you to make sure you have designed a good experiment • Uses a rectangle (table) format

13. Experimental Design Diagram Title of the Experiment State Hypothesis: DV: C: