How to mess up a bar chart
The war on infographics

Nothing works while visualizing a poll 1

Reader John G. sent an example of a spectacular failure in automated chart generation (via a LinkedIn poll result display):

LinkedinpollAlmost nothing works at all.

The survey question should be placed directly above and inside the box containing the bar chart.

Zero means zero, not the unspecified small values indicated by tiny bars.

Any pollster will use the poll result to make general statements about some predetermined group of people, and so the emphasis should be on the proportion of responders as opposed to the absolute number of responders selecting any given response.

Half-persons do not exist despite what the (excessive) gridlines imply.

The color scheme chosen for the bar chart conflicts with that chosen for the demographic data shown below.

The term "overall demographics" should be replaced by "all respondents". Demographics can be placed above the bottom three sections which all pertain to demographic data.

It's not clear if the gender symbols scale with the proportion of respondents but in any case, all readers will be forced to read the small-font data labels at the bottom to make sense of the data.

Nor does one know what job title a responder holds if he is not a "manager". It is also curious as to why "manager" is given the darker tint in the "overall demographics" section but the lighter tint in the "YES!" section.

The "all respondents" data should be replicated on each of the two bottom charts since they act as a reference point to interpret the demographics for each response.

Do away with the Age column since no data is available.

Finally, as John pointed out:

With only three respondents answering YES to the question, how can the distribution be 50% managers and 50% everybody else?  With four total respondents, how can the overall demographic be about 66% managers and 33% everybody else?

Perhaps one of the three left the question unanswered? (typically, a separate category of "unknown" would be created for this purpose.) Perhaps half-persons do exist in this universe?

In what follows, I'll assume that 1 of the 3 people saying "YES!" is a manager, while the one responding "What is an arc flash survey for?" is also a manager, making two managers out of four respondents.

Jc_linkedinpollThe following display uses the small-multiples principle, presenting subgroup data the same way as the overall data. The emphasis is on proportion of responders.

The "female" category is labelled "NA" as opposed to zero because we do not know how females would respond since no woman filled out the survey; this is not the same as saying females would not select "YES!" or "What is the survey for?".

The "Overall" section is both a data display itself and a reference point for the other sections of the chart.

The horizontal orientation has the advantage of keeping the bars close together - but it has the disadvantage of awkward positioning of the names of the responses. Conversely, if flipped vertically, the names of the responses would be neatly displayed but it would be difficult to keep the columns close together.




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You do find the best bad charts.

It's reasonable to ask whether a chart is needed to report on four responses. But even if you decide that it's merited, is there an issue with expressing results as percentages? While 3/4 does equal 75%, it seems to me that percentages connote a level of statistical confidence (and thus generalizability) that is absent here. I'd be curious to hear what others think.

Also, a quibble: As I look at it, your redo still suggests that 50% of three managers answered "yes." I think the quantities in the legend don't match your assumptions.

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