Decide on your message and plan your visual




This column graph was part of a presentation given by a multinational information firm to
a group of medical researchers.

The graph depicts the outcomes of children with chronic medical conditions who were diagnosed with influenza and treated with a specific antiviral drug compared to those who
were not treated with an antiviral drug. The graph has been redrawn and the name of the
drug removed.

The visual message of this graph is incongruent with the intended message. The intended message of the graph is that treatment with the antiviral drug decreases the risk of influenza-related complications in children with chronic medical conditions. Because English readers read from left to right and because the designer placed the treatment group to the left of the untreated group, the visual message is that of increase.




There are numerous other difficulties with the original column graph. The vertical orientation of the text makes reading the X-axes labels challenging. The title provides insufficient information to let the graph stand-alone. The categories are not ordered in any logical way. The scale of the Y-axes is such that two of the columns are vanishingly small.




This revised graph addresses these problems, but problems remain. The revised graph shows users the rates of influenza-related complications in the treated and untreated cohorts, but doesn’t directly show the effect of treatment. In addition, the categories are ordered by the frequency of the complication, not by the effectiveness of treatment.

The designers could have “done the math” for the users and directly depicted the effectiveness of treatment expressed as absolute risk reduction.




Or, they could have depicted the effectiveness of treatment expressed as relative risk reduction.




The two alternative visuals that directly depict the effectiveness of treatment give users a much clearer picture of the degree to which influenza-related complications in children with chronic medical conditions will be lessened by antiviral therapy.

See the difference?