1. Graphing Data

2. OGT Benchmark SI-A
Participate in and apply the processes of scientific investigation to create models and to design, conduct, evaluate and communicate the results of these investigations.

3. OGT Indicator SI-5
Develop oral and written presentations using clear language, accurate data, appropriate graphs, tables, maps and available technology.

4. OGT Indicator SI-6
Draw logical conclusions based on scientific knowledge and evidence from investigations.

5. 1. Create a data table labeled with units.
Graphing Notes
1. Create a data table labeled with units.
Time
(s)
Distance (m)
Red Car
Blue Car

6. 2. Decide what type of graph
*Line (scatter) – shows changes over time, relationships or trends

7. *Bar – compares different things

8. *Pie (circle) – shows parts or % of a whole thing

9. 3. For line graphs (and bars),. determine the range and scale
3. For line graphs (and bars), determine the range and scale of your variables
* range – lowest number to highest number
Start at zero if it’s reasonable
Example: range of 5 to 50 – start with zero
Example: range of 2000 to 3000 – don’t start with zero – most of your graph will be empty space

10. * scale – labels for each line on the graph
Must be evenly spaced, counting by a reasonable number – 2, 5, 10, 25, 100, etc
For line graphs, number the lines, not the spaces
Example: - each line is worth 2

11. 3. Label the horizontal axis with the independent variable and its unit – the independent variable is the one you set ahead of time

12. Label the vertical axis with the dependent variable and its unit – the dependent variable is the one you are testing for
Choose a title for your graph.
Plot your data points.

13. 8. The graph can then be used to predict unmeasured data points.
Determine the trend in the data – draw a “best fit” line through your data points.
8. The graph can then be used to predict unmeasured data points.
* interpolate points within your data range
* extrapolate points beyond your data range

14. Graphing Example
Determine the relationship between the number of times a cricket chirps in a minute and the air temperature.
Temperature in degrees F
# of cricket chirps/min 90 3 80 6 70 11 60 15

15. *Starting with zero, most of the graph is empty

17. * With a “best fit” trend line

18. *Use the graph to interpolate the # of chirps at 75 degrees F.
*Use the graph to extrapolate the # of chirps at 100 degrees F.