1. Graphing (a Crash Course)
Essential Questions:
How do scientists organize data?
What graph is appropriate for a type of data?
How does graphing help us understand scientific questions/problems?

2. Why Graph?
When performing an experiment, a scientist must be able to record an immense amount of data and process that data into useful information.
This is done by converting raw data into charts or tables.
Then, the data must be graphed such that it can be interpreted by the public.
Graphs are visual representations of data.

3. Part 1: Tables and Charts
Tables and charts are created for organizing data from raw data.
The chart should show how a trend occurs over several occurrences, (months, trials, categories, etc) or over time.
Once data is organized, it can be graphed!

4. Discuss with your group
When you see a data table or data chart how do you determine what is the independent variable and what is the dependent variable?

5. Part 2: Graphing Data A) Pie Graphs
Pie graphs are useful in showing percentages.
Displays how different categories are represented within a topic area.
Sample: How many land does Asia take up in the world?

6. Part 2: Graphing Data B) Bar Graphs
A bar graph is a way of showing relationships between variables, typically items that being compared.
It contains an x and y axis.
These are 2 lines that meet at a right angle.
It uses a series of columns to display data.
Example, how does the number of farms in 1910 compare with 1990?
Notice:
The x and y axis are always labeled.
The graph has a title.
The bars are vertical.
The numbers on the Y axis are in sequence for an accurate comparison.

7. Part 2: Graphing Data C) Line Graphs
A line graph shows the best relationship between 2 variables.
Along the x-axis (horizontal) is the manipulated or independent variable.
Along the y-axis (vertical) is the responding or dependent variable.
Has one or more lines connecting a series of points.
Notice:
Time is on the x-axis (independent variable)
Distance is on the y-axis (dependent variable)
Distance and time are in sequence.

8. Discuss with your group
DRY MIX
What is it and what does it mean?

9. Constructing a graph
Decide which variable to place along the x and y axis.
Decide on a scale for your graph.
Start by discussing with your group. How do you determine the scale to use for a graph?
Must be as large as possible within the limits of the paper and still include the largest item of data.
Select your scale with ease of locating points, multiples of 1, 2, 5, or 10 are easiest.
Your Turn! Flip on the back of your notes and let’s conduct a graphing experiment!

10. Graph the following data
Concentration of Oxygen in Water
Temperature (°C)
Oxygen Concentration in Freshwater (ppm)
Oxygen Concentration in Seawater (ppm) 1
14.0
11.0 10
11.5
9.0 15
10.0
8.0 20
7.5 25
7.0 30
6.0