Graphs and Graphing Data

Biology

Ms. Haut

Introduction to Graphing

• Both figures display the same information, but differently.

• Which figure is easier to understand?

• If you need specific data (exact number) which figure would you use?

Figure 1. Grade Distribution for Students Enrolled in Science Class

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Table 1. Grade Distribution for Students Enrolled in Science Class

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Table 1. Grade Distribution for Students Enrolled in Science Class

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Table 1. Grade Distribution for Students Enrolled in Science Class

Steps to Making a Graph

1. Identify the Variables

– 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 number (age,

weight, etc.) or categories (gender, color, etc.)

• On graphs, theindependent variablealways goes on theX-axis.

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Experimental Variables

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 isalways on the Y-axis.

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Steps to Making a Graph

1. Identify the Variables

2. Determine which type of graph to use

Types of Graphs• Two common types of graphs:

– Bar graphs

– Line graphs

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

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Biology Test ScoresFig. 1

Absences vs. Scores

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Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Types of Graphs

Bar graphs are used when the independent variable has categories. •Boys/girls •Adults/children •Salt water/distilled water /tap water •Etc.

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Biology Test ScoresFig. 1

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.

Absences vs. Scores

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AbsencesTest

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Fig. 2

Steps to Making a Graph

1. Identify the Variables

2. Determine which type of graph to use

3. Choose a scale for each axis that includes all values. Number your gridlines evenly.

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Making a Graph

Choose a scale for each axis that includes all values. Number your gridlines evenly.

Fig. 3

Steps to Making a Graph

1. Identify the Variables

2. Determine which type of graph to use

3. Choose a scale for each axis that includes all values. Number your gridlines evenly.

4. Label the X-axis and the Y-axis with units

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Making a Graph

Label both axes, including units. Fig. 3

Steps to Making a Graph

1. Identify the Variables

2. Determine which type of graph to use

3. Choose a scale for each axis that includes all values. Number your gridlines evenly.

4. Label the X-axis and the Y-axis with units

5. Plot the Data Points and Connect the dots or draw the bars (USE A RULER)

Making a Graph

Plot each data point and connect your dots with a line.

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Fig. 3

Steps to Making a Graph

1. Identify the Variables

2. Determine which type of graph to use

3. Choose a scale for each axis that includes all values. Number your gridlines evenly.

4. Label the X-axis and the Y-axis with units5. Plot the Data Points and Connect the

dots or draw the bars (USE A RULER)

6. Give your graph a proper title.

Making a Graph

Give your graph a descriptive title.

Derby, S. (2004) Graphs and Graphing PowerPoint Presentation.

Fig. 3