1. Graphing Data
Mrs. Stewart
Biology

2. Why use a graph? Scientists use graphs to
organize large tables of data
Easily see trends,
Make comparisons
Make connections
Visualize results

3. Which type of graph to use?
The form and shape of the graph depends on the type of data and what story it can tell.
Most commonly used graphs in science:
Line graph
Bar graph
Pie graph
Scatter plot

4. Line Graphs
Line graphs are best for showing change over time to reveal trends.
For example: Tracking the weather pattern by plotting monthly rainfall

5. Bar Graphs Bar graphs are good for comparing amounts.
For example: Total amount of rainfall in New York City vs. that in Denver or in New Orleans

6. Pie Graphs Pie graphs are designed to show percent or part of a whole.
For example: The percentage of days in the year that are rainy, cloudy, or sunny

7. Choose the right graph

8. Choose the right graph

9. Choose the right graph

10. Required Parts of a Graph
Title
Axis titles – including the units of measure
Key/Legend

11. Graphing variables Independent variable (variable being tested):
graphed on the x axis
Dependent variable (what was measured):
graphed on the y axis

12. Reading/Interpreting a Graph

13. Mr. M’s class grades: Based on this graph:
The largest percentage of students received what grade?
Estimate what percentage of students received a B.
Estimate what percentage of students received an A.
Do you think Mr. M’s class is hard? Why or why not?
Mr. M’s class grades:

14. The scatter plot shows a bus stop where those waiting at the bus are plotted by their height and by their age.  Identify which dot goes with which passenger.

15. What was the dependent variable?

16. What was the independent variable?

17. What can the researcher conclude about sunlight exposure times from this data?