How to Create Bar
and Line Graphs
Draw the Axes
Identify the Axes
Y- Axis
X- Axis
Identify the Axes
Y- Axis
Dependent
Variable
(what is observed
and measured)
X- Axis
Independent
Variable
(what is changed by
the scientist)
DRY MIX
One way to remember which data goes on which axis is
the acronym DRY MIX.
D.R.Y.
D- Dependent
R- Responding
Y- Y-axis
M.I.X.
M- Manipulated
I- Independent
X- X-axis
Title
 Write an appropriate title for the graph at the top.
 The title should contain both the independent and
dependent variables.
Scale
 Decide on an appropriate scale for each axis.
 The scale refers to the min and max numbers used
on each axis. They may or may not begin at zero.
 The min and max numbers used for the scale should
be a little lower than the lowest value and a little
higher than the highest value.
 This allows you to have a smaller range which
emphasizes the comparisons/trends in the data.
Scale
•The Y-axis scale
is from
0-100.
•The largest
value though is
only 35.
Scale
•The Y-axis scale
is now from 040.
•This does a
better job
emphasizing the
comparisons
between coins.
Intervals
 Look at your minimum and maximum values you set
up for both the Y and X-axis. (For most bar graphs,
the X-axis will not have numerical values.)
 Decide on an appropriate interval for the scale you
have chosen. The interval is the amount between one
value and the next.
 It is highly recommended to use a common number
for an interval such as 2, 5, 10, 25, 100, etc.
Intervals
The interval for
the Y-axis is 20.
The X-axis does
not have
numerical data
and does not
need an interval.
Labels
 Both axes need to be labeled so the reader knows
exactly what the independent and dependent
variables are.
 The dependent variable must be specific and include
the units used to measure the data (such as “number
of drops”).
Labels
DV label
IV label
TAILS
Another handy acronym to help you remember
everything you need to create your graphs…..
T.A.I.L.S.
Title
Axis
Interval
Labels
Scale
TAILS
Title: Includes both variables
Axis: IV on X-axis and DV on
Y-axis
Interval: The interval (4) is
appropriate for this scale.
Label: Both axes are labeled.
Scale: Min and max values are
appropriate.
Bar Graphs vs
Line Graphs
Bar Graphs
•Bar graphs are descriptive.
•They compare groups of data such as amounts and
categories.
•They help us make generalizations and see
differences in the data.
Example
Another example
Line Graphs
•Line graphs show a relationship between the two
variables. They show how/if the IV affects the DV.
•Many times, the IV plotted on the X-axis is time.
•They are useful for showing trends in data and for
making predictions.
Example
Another example
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