1. Graphing
Why Do We Do It?

2. I. Why do we make graphs?
A. It’s a picture the quickly confers information
B. In Science, graphs can be used to summarize experiments
C. Graphs must be complete and labeled in order to be useful

3. II. Data Tables vs. Graphs
Data tables are tables which hold information. (this is a data table not a graph)

4. III. Collecting Data A. Data should be placed into a data table
B. Random sampling - if data comes from a survey , it should be random in order to be representative of the population

5. III. Types of Graphs A. There are three main types of graphs
1. PIE - used to show parts of a whole

6. III. Types of Graphs
2. BAR - used to compare groups

7. III. Types of Graphs
3. LINE - used to show change over time

8. IV. Making Graphs A. Graphing Criteria 1. Axis labels - 2. title
the x axis is the horizontal axis
the y axis is the vertical axis
2. title
3. Units (ex. g, ml, cm)
B. A ruler must be used when making a graph

9. Making Graphs EXAMPLE

10. V. Applying Graphs to Science
A. Making meaning out of graphs
1. Independent variable - the variable in an experiment that is manipulated (aka experimental variable)
2. Dependent variable - the variable that changes due to the independent variable, this is the variable that is measured

11. V. Applying Graphs to Science
B. The dependent variable is usually placed on the Y axis (don’t forget units)
C. The independent variable is usually placed on the X axis

12. VI. Graphs Can Show Trends
A. Line of Best Fit- this line shows the correlation (relationship) between the independent and dependent variable

13. VII. Graphing Reflection Questions
1. Why do we make graphs?
2. How do data tables and graphs differ?
3. What are the three types of graphs and their uses?
4. Describe the X and Y axis.
5. Define independent and dependent variables and which axis they belong on.

14. EXAMPLE PROBLEM
Julie wanted to see how well different diet pills works. She took a different diet pill each month and recorded her weight loss.
A) What is the independent variable?
B) What is the dependent variable
C) What type of graph should be used?