SCIENCE SKILLS
Interpreting Data: Graphs
Suppose you want to measure your
family’s heart rates during different
activities. A line graph would be a good
choice. This graph compares two variables
(heart rate and different activities). A line
graph shows data by connecting dots
plotted on the graph. Can you find any
patterns in this line graph?
Family Heart Rates During Different Activities
Y-axis
100
Heart Rate
70
60
Dad
Katie
95
A bar graph uses bars to show data.
This bar graph shows how high a new
plant grows each week. Place your finger
at the top of the bar for week 5. Move
your finger to the left to see how many
centimeters the plant has grown.
With graphs, we can organize, compare,
analyze, and interpret data.
Y-axis
Plant Growth
20
15
10
5
0
Week
1
Week
2
Week Week Week
4
5
3
Time Since Planting
Week
6
X-axis
90
90
80
Mom
Pie charts are
also commonly
used in science.
Height (cm)
A graph has a title that describes what
the graph shows. Most graphs have two
axes (AKS-eez). The X-axis is horizontal
(across the bottom), and the Y-axis is
vertical (up the left side). The two axes
represent different sets of data. Usually
the Y-axis is the dependent variable.
It changes when data on the X-axis
(the independent variable) changes.
© iStockphoto.com/
Cihan Demirok
A graph helps you organize and present
data, or information, you collect. With
a graph, you can visually compare data.
This makes it easier for readers to analyze
and interpret the data. Line graphs and
bar graphs are the most common graphs.
80
85
82
80
74
65
75
62
68
60
50
X-axis
lying
down
sitting
jumping
jacks
Activity
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sit-ups
oH
ow are graphs useful?
oW
here have you seen
graphs outside of school?
oC
ompare and contrast a
line graph and a bar graph.
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