Experimental Design

I. Parts of an Experiment A. Independent variable: the factor changed in an experiment B. Dependent variable: any factors changing in response to the independent variable C. Controlled variable: any factors held constant during the experiment Example: Plant Growth in response to amount of water

II. Line Graphs A. X-axis = independent variable (“the cause”) B. Y-axis = dependent variable (“the effect”)

III. Bar Graphs A. Used to represent data for different categories (usually non-numerical) B. Y-axis should still have dependent variable

IV. Best Fit Lines A. To show a trend, you can draw a line on your graph that best represents the general pattern of the points B. Your line does not have to go through any of the points