Grossly Misleading Graph
From:
Transactive Memory in close Relationships
This falls into a classic error in displaying data - note the y axis starts at 20, not zero. This magnifies the effect - it makes it look like the difference between the values is relatively much greater than it actually is.
Consider the Natural, assigned and unassigned values on the right 2 bars. As displayed, it looks like the values are 24 and 32 (I am rounding to the nearest whole number - the paper does not specify the totals. So from the graph it would seem that the ‘Assigned Expertise’ is 4 / 12 as high as the ‘No Assignment’ value. That is, a glance at the chart would imply a 3-fold improvement of recall for ‘Assigned Expertise’ over ‘No Assignment’.
What are the real numbers? More like this:
Still an interesting result, but nowhere near as much so as the original chart implies.
You see this a lot in charts during business presentations - it is a temptation to make a result seem as dramatic as possible, but it distorts the actual result, and may bias us towards a particular interpretation. I always look at any presentation chart to make sure that the axis starts at zero.
For more info on charts and best practices, see here:
EIA Guidelines for Statistical Graphs
The page concerning bar charts in particular is here:
Vertical and Horizontal Bars, Pie and Dot Charts, and Three-Dimensional Features
Here’s a comparison of the two graphs, both converted to the same format:
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