Data Viz Done Right

November 7, 2011

Makeover of a Makeover – Waterfall vs. Side-by-side Bar Chart

5 comments

One of the great things about the data viz world is that people are always willing to listen, learn and share.  Cole Nussbaumer over at storytelling with data (a great blog you should follow) recently conducted a visual makeover on some horrible charts submitted during a class she was teaching. and she was willing to share her data with me so that I could make my own viz.  Where else do you experience such camaraderie? 

The improvements she recommends are fantastic, but I recommended one improvement to this chart she created:

Typically when I see side-by-side bar charts I’m looking to compare the bars that are next to each other.  However, in this case, the bars are not necessarily related; they are simply a list of expenses and income next to each other.  I recommended she create a waterfall chart like this one done with Tableau:

Storytelling with Data Waterfall

To me, a waterfall chart communicates the expenses vs. income story of this data more effectively

  1. The bar sizes make comparisons easy.  It’s clear that Programs are the largest expense and Grants are the largest income.
  2. You can easily see the total variance without having to do the math in your head.
  3. Other Expenses are much larger than Other Income.  I wonder what’s included in those expenses.  Looks like an area for investigation.
  4. This group should probably focus a bit more on Sponsorships so that they’re not so dependent on Grants.

I could have included labels for all of the bars, but I wanted to show the patterns and relative sizes without the numbers being a distraction.

You can download the original Excel data here and/or the Tableau workbook here.

P.S. I chose red/green bars for two reasons: (1) most people understand red as negative and green as positive when reading financial figures and (2) to annoy my friend Steve Wexler of the Data Revelations blog (another you should follow), who hates this color scheme more than anyone I know.

5 comments :

  1. Good post Andy. I really needed this at the conference while trying to help someone 'arrive' at a SxS in a Tableau Dr session. All too frequently people approach with a rope, point at a sturdy tree limb and the automatic reaction is to run and grab a ladder. Helpful, right? "Really?" is often a good way to kick off a conversation leading to better analysis.

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  2. Nice makeover, Andy! I agree that the 'Other' category is worth digging into (it wasn't even shown in the original chart, which seemed super misleading). I like the waterfall chart for this data except for the negative y-axis carrying across to income (you could possibly keep the axis positive and put income first?). Also, like your friend, I disdain the red/green combo. In addition to looking like Christmas (though 'tis almost the season), it's missed by most colorblind.

    Happy to share. Let me know if you're up for a makeover duel at some point in the future! ;-)

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  3. The makeovers are great fun Cole! I keep a log of junk charts to post about. I'll reach out to you for a duel. :-)

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  4. Sorry. I can't download Tableau Workbook

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    Replies
    1. I've republished the workbook. You should see it now.

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