Well, maybe not the absolute worst because I have seen some bad ones. But this one is in the Top 10.
This slide was part of a larger, information-style presentation related to an environmental planning report. The slide was one of 37 slides. This slide was intended to show a quick summary of historical data, the completeness of the data, and that some data analysis was part of the planning efforts.
Good intentions. Here is why the slide fails so miserably as effective communication
Too Much Information to Comprehend Quickly
There are four graphs on a single slide. Each graph contains two sample events, sixteen years, and five data points per sampling event. That is 160 data points per graph or 640 relatively disparate data points.
Graphs are indeed a quick way to summarize large sets of data. It is also true that graphs should be multi-variate in most cases. Any single graph achieved these two goals. Including four graphs together muddied the water.
No Clear Message or Takeaway
Every reader of the graph can take multiple messages from the slide. The slide creates confusion because there are multiple messages, and it is unclear what the trusted advisor wants the decision makers to take away from it.
Plus, there is no room on the slide to add the central message, if there is one.
Decision Makers Do Not Understand Box Plots
On page 82 of Communicating to Decision Makers, the equivalence of the box plot (box and whisker diagram) and the cone diagram is recognized. In practice, a non-technical audience of decision makers will understand the cone diagram much more easily than the box plot. In fact, the non-technical audience very seldom understands the choppiness of the box plot and is turned off by it.
The Vertical Scales Are All Different
The decision maker has to work hard to understand the comparative analysis because all four graphs on the same slide have different scales. The trusted advisor is taking the burden off themselves and transferring it to the decision makers. It is in poor graphical form, and it is also disrespectful.
It is a poor slide, but certainly, the top two graphs could have been shown at the same scales. The same could have been done for the bottom two graphs. The slide would still have been poor, but at least it would have shown some respect to the decision maker.
My first reaction was the choice of red was a poor one from the standpoint of colorblindness. After viewing the slide in black and white, it was not as indistinguishable as I had first imagined.
Red, yellow, and orange are great highlight colors, and possibly the trusted advisor was moving in that direction. The issue is that the red and the yellow, in this case, are primary colors, not highlight colors.
Red tends to elicit negative reactions as a primary color, so maybe the trusted advisor was subliminally trying to draw a negative connotation to the Rocky River.
Thinking About It
The positive (and trustful) way to look at this slide is that the presenter just tried to cram too many slides into one short presentation. And maybe they were not well trained. And whoever reviewed it was not well trained either.
The more realistic (and respectful to the presenter) way to look at this slide is that everyone is a professional and knows what they are doing. At least that is the starting point.
But the presenter cannot have it both ways.
I will stay with the positive (and trustful) perspective on this one. That means better training for the presenter, better training for the reviewer, and better business processes associated with catching crappy slides before they get in front of decision makers.