Poor Form review

Kierann Healy’s “Badness” represents things you need to avoid when making a graph. The key point of the reading was that there is a noticeable difference for viewers between graphs, because some of them are obviously easier to read than others. Through the reading, the book encouraged me to look for unconscious choices I make while making graphs and thinking about figures. The author explained three factors which lead to badly designed graph. They are related to aesthetics, substantive evident of data and issues with perception. The aesthetic factor presented in the book is emphasized to be relatively easy to deal with on a graph. By getting rid of unnecessary ‘junks’ from figures and keeping perfect ratio of data-to-ink the graph will be truly effective. Using incorrect or unreliable data is another factor which must be taken into consideration when making a graph. A person making it should fully understand data that he or she is using and also be cautious to not mislead viewers with the ‘halo effect”.  The last factor - issue with perception- was described as how to deal with and combine actual data and the shape of a graph. The book explained that both aspects should be visually pleasant for viewers, so they can easily understand it. Default settings are the simplest forms to understand for viewers, but some other charts tend to remain more challenging to read. I agree with the first and the last factor: making figures junk-free and visualizing data in a more perceptive way. However, I’m not not convinced by the second factor, to not mislead viewers with the halo effect. If a person is only visualizing data, they don’t know if the data is biased. Thus, my question is how to verify by oneself if the data is biased or not?