Junk Charts

Oscar diseconomy

Business Week dissected the beneficiaries of the Oscar show as shown on the right.  Although this doesn't work well as a data graphic, if thought as a variant on the data table, it is more engaging for readers.

Lets have some fun with the Oscar statue.  First, putting a bar chart next to the statue confirms that the height of the segments (rather than the area) is in proportion to the dollar values (below left).

Tufte, Chambers and others have shown that our eyes react to the areas, not heights.  So next, I estimated the areas but stretched them out into segments of equal width.  Squeezing the entire column back down to the height of the statue, the following chart (below right) puts perceived proportions next to the true proportions, displaying visually the extent of distortion. 

Reference: "News you need to know", Business Week, Jan 28 2008.

Memo to new owner: what's the point?

Software company Siebel's new owner Oracle put out an embarrassing ad this week; I excerpted the bottom half here. 

The headline of the ad (see the full ad here) screams in large, bold, white letters: "BUSINESS IMPACT  COUNTS."

Unfortunately, the chart answers no questions but raises a full bunch:

• How were these ratings obtained?  Which experts determined the scores?
• What is the scale?  How much better is a quarter of a circle?
• What does it mean by "business impact"?  What exactly is being measured?
  
• Why are the circles of differing radii?  What do radii signify?
• Isn't "Adoption" the category that has the largest separation between the two companies?  Why isn't that highlighted?
• What is the order of the five criteria?  It is not alphabetical, not ranked by either company's category scores, nor by the differences in these scores

Wi-fi nation: a terrific map

Here is one terrific map, courtesy of Ray Vella at Business Week.

 

 

This map works on two levels:

• The red and green dots provide strong visual cues to support the conclusion that Wi-Fi networks are being widely deployed across American cities, except in the mid-west
• The three shades of brown show the number of networks installed or planned in each state.  Inclusion of such state-level information justifies the printing of state boundaries.  Without plotting state-level information, state boundaries become chartjunk, as in the heat wave maps I previously discussed.

What's more, we can assimilate the city and state levels.  For example, focusing on Texas, we see from the dark brown shade that it is a state with many networks, and then from the dots, we can see further where those networks are.

A few minor improvements can be made:

• Tell us the upper bound of the legend, name the legend: by changing 10+ to 10-X, the designer not only provides us another piece of data but also harmonizes the presentation with the other two categories. Besides, the legend needs a title
• Be more friendly to the color-blind: the red-green contrast should be avoided as much as possible.  If a graphic designer is reading the blog, please tell us where we can find studies of color contrasts
• Use a softer national boundary: the solid black line sticks out against the soft background and it is the least important bit on the map

• One would expect the choice of three shades of brown and the intervals used for each shade to be keyed to the frequency histrogram of the number of networks (shown right).  The current division divides the 50 states into groups of 8, 16 and 26.  Are there better divisions?

Finally, most readers will find the number of networks to be a dissatisfactory metric because more populous states will likely install more networks.  A density measure such as networks per person or per household or per unit area would have been more telling.

Reference: "Wi-Fi Nation", Business Week, Aug 1 2005, p.12.