Psych 1010 1
Chapter 3: Visual Displays of Date
The most misleading graph ever published
Was from Ithaca Time, “why does college cost so much.”
o Lie 1: The graph treats unequal scaled as if they were equal. This lie
uses identical distances to represent very different time frames
o Lie 2: The graph unites incompatible measures. This lie compares an
ordinal measure to a scale measure
o Lie 3: The graph uses misleading starting points. This lie arbitrarily
begins the line representing quality of education lower than the line
representing tuition costs as a proportion of income, suggesting than
an institution already failing to deliver what students are paying for
has, over the last 11 institution already failing to deliver what
students are paying for has, over the last 11 or 35 years, become
o Lie 4 : The graph reverses the implied meaning of up and down.
Techniques of Misleading with Graphs
Most common ways to mislead viewers with graphic tricks:
o The false face validity lie. False validity refers to whether the method
used to collect data seems (on the face of it) to represent what it says
it represents. False face validity is when the method seems to
represent what it says, but when you dig a little deeper, it does not.
o The biased scale lie. This slants information in a particular way
o The sneaky sample lie- when the people who participate in a study are
preselected so that the data turn out in a particular way.
o The extrapolation lie- assumes knowledge of information outside the
o The inaccurate values lie- sometimes it involves telling the truth in
one part of the data but visually distorting it in another place.
o The outright lie- making up data to lend an air of legitimacy to an air
of legitimacy to an otherwise weak argument.
Common Types of Graphs
Scatterplot: a graph that depicts the relation between two scale variables.
How to create a scatterplot:
1. Organize the data by participant; each participant will have 2 scores,
one on each scale variable.
2. Label the horizontal x-axis with the name of the independent variable
and its possible values, starting with 0 if practical.
3. Label the vertical y-axis with the name of the dependent variable and
its possible values, starting with 0 is practical
4. Make a mark on the graph above each study participant’s score on the
x-axis and next to his or her score on the y-axis. Linear relation: between variables means that the relation between
variables is best described by a straight line.
Non linear relation: between variables means that the relation between
variables is best describe by a line that breaks or curves in some way.
Line graphs: used to illustrate the relation between two scale variables;
sometimes the line represents the predicted y scores for each x value, and
sometimes the line represents change in a variable over time.
Time plot or time series plot: a graph that plots a scale variable on the y-
axis as it changes over an increment of time labeled on the x-axis.
Here is a recap of the steps to create scatterplot with a line of best life:
1. Label the x-axis with the same of the independent variable and its
possible values, starting with 0 if practical.
2. Label the y-axis with the name of the dependent varia