1. Graphs and Graphing Data Pre-AP Biology Ms. Haut

2. Variable: A factor in an experiment. –Independent variable: The factor that is different between groups. The topic of interest in an experiment. Has two or more levels. Levels can be numbers (age, weight, etc.) or categories (gender, color, etc.) Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Experimental Variables

3. –Variable: A factor in an experiment. Independent variable: The factor that is different between groups. The topic of interest in an experiment. On graphs, the independent variable always goes on the X-axis. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Experimental Variables Fig. 1

4. Experimental Variables –Variable: A factor in an experiment. Dependent variable: The factor being measured in the experiment. Almost always numerical On graphs, the dependent variable is always on the Y-axis. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 1

5. Types of Graphs Two common types of graphs: – Bar graphs – Line graphs Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 2 Fig. 3

6. Types of Graphs Bar graphs are used when the independent variable has categories. Boys/girls Adults/children Salt water/distilled water /tap water Etc. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 2

7. Types of Graphs Line graphs are used when the independent variable has numbers. Hours of television watched Age (in years) Calories eaten per day Etc. Both line graphs and bar graphs show the relationship between independent variables and dependent variables. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 3

8. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Making a Graph 1) Choose a scale for each axis that includes all values. Number your gridlines evenly. Fig. 1

9. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Making a Graph 2) Label both axes, including units. Fig. 1

10. Making a Graph 3) Plot each data point and connect your dots with a line. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 1

11. Making a Graph 4) Give your graph a descriptive title. Derby, S. (2004) Graphs and Graphing PowerPoint Presentation. Fig. 1