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Unformatted text preview: Graphing Guidelines
Graphing Often the goal of an experiment is to find the
relationship between two variables. As one variable changes, so does the other.
As Graphing is a useful way to visualize and
describe these relationships. Because the use of graphs is so common in
sciences, it is important for you to know how
to construct and interpret graphs. When preparing graphs for this class, keep
When Graphing Guidelines
1. It is done on graph paper.
2. Use the x-axis for the independent variable (the
variable changed by the experimenter) and the
y-axis for the dependent variable (the variable
3. The scale you select should be easy to work with
such as one square represents 1, 2, 5, or 10 or
five squares represents a unit of 1, 10, or a
multiple of ten (20, 100, 0.1). Never change the
scale along an axis. However, you may use a
different scale for each axis.
different Graphing Guidelines
4. Select a scale that uses the greatest
portion of the paper. Leave enough room
to title your axis and graph.
5. Label what the axes represent by including
the measurement and its units. For
example: "Length (cm)" or “Time in
seconds” Graphing Guidelines
6. For line graphs, plot your points.
Sometimes you will be asked to connect
• Other times you will be asked to draw the line
of best fit. The line should pass as close as
possible to each of the points but should not
be connected point-to-point. If the relationship
appears to be linear, the line of best fit should
be a straight line.
be Graphing Guidelines
7. Title the graph. Make sure you describe
what is represented on the horizontal and
8. If you are plotting more than one curve on
the same graph, include a legend that
identifies the curves. Use different colors
or different types of lines such as solid or
dashed lines between them.
dashed Example Graphs
Example Practice Graphs
Practice Recall that a bar graph is useful for
comparing information collected by
counting. We are going to use the clothing
of students in this classroom to demonstrate
how to make a data table and bar graph.
We will look at the shirt color of boys and
girls in the room.
girls Practice Graphs
Practice Step 1: Gather Data An easy way to
organize our data is to
create a table. Let’s
use this table to fill in
our data. Color
Color # of Boys # of Girls Red Black Grey Blue White Multi Other Practice Graphs
Practice Step 2: Create the Graph
Independent variable (x-axis): ________
Dependent variable (y-axis): __________ Choose two different colors to use (one to
represent boys, one to represent girls).
represent Key Features of Bar Graphs
Axis are labeled with units
Legend Check your graph to make sure you have these three features Line Graphs
Line Recall that line graphs are useful for showing
trends. Problem: In an experiment, you check the air temperature at
certain hours of the day. At 8 A.M., the
temperature is 27 ○C; at 10 A.M., the temperature
is 30 ○C; at noon, the temperature is 32 ○C; at 2
P.M., the temperature is 31○C; and at 4 P.M., the
temperature is 30 ○C. Graph the results of your
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- Winter '11