1. Experimental Design: Variables Erin Wasson EME6507 May 30, 2013

2. Experimental Design Variables Variable any component of an experiment that changes or can change Types of Variables 1 independent variable 1 dependent variable 1 control constants

3. Independent Variable Experimenter changes or manipulates this variable Test variable Manipulated variable Should have only 1 A girl is manipulating her independent variable.

4. Dependent Variable Outcome variable Experimenter measures this variable Changes because of the independent variable Usually only 1 The plant growth in these test tubes could be a dependent variable.

5. Examples Test Independent Variable Dependent Variable Growth of plants in different types of light Different types of light Height of Plant Growth (meters) Absorbance of different paper towel brands The brand of paper towels Amount of liquid absorbed The effect of music on heart rate Types of MusicHeart rate

6. Graphing Variables Height (cm) Type of Light independent dependent