In the real world, visualizations are usually accompanied by a message, hence, it is interesting to study how visualizations lead to a message level deception. There are various ways to visually deceive viewers even at the message level, e.g., presentation of deliberate misinformation, distractions, information overload, or through deceptive techniques applied on the level of visual encoding. Starting with complete data, two broad classes of message level deception – Message Exaggeration/Understatement, and Message Reversal, can be identified.
Message Exaggeration/Understatement
This kind of deception happens when the fact is not distorted, however, but the extent of the presented fact is tweaked, i.e., the fact is exaggerated. For example, if a chart compares two quantities – A and B, where A is bigger than B, but the users are presented with the fact that A is bigger than B, but the ex- tent is exaggerated. This type of deception affects the “How much” type of questions, such as “How much do you think is quantity A bigger than quantity B?”
Message Reversal
This type of deception happens when a visualization encour- ages users to interpret the fact in the message incorrectly. For example, if a chart compares two quantities – A and B, where A is bigger than B, the users perceive the message as A is smaller than B. Thus, users perceive the incorrect message due to a distorted visualization, even though the actual data is presented. This type of deception affects the “What” type of questions, such as “What does the chart show?”.
References:
https://medium.com/@Infogram/study-asks-how-deceptive-are-deceptive-visualizations-8ff52fd81239#.f89mt9glu
http://lsr.nellco.org/cgi/viewcontent.cgi?article=1506&context=nyu_plltwp