3 Replies Latest reply on Feb 2, 2012 11:56 AM by Jonathan Drummey

    Unstacked area chart - good idea or bad form?

    Jonathan Drummey

      I was trying out different mark types in Tableau 7 and found that despite the statement in the Help at http://onlinehelp.tableausoftware.com/v7.0/pro/online/en-us/viewparts_marks_marktypes_area.html that Stack Marks must be on in order to get an area chart, Stack Marks can be off and Tableau will generate the area chart. When using the Color shelf tableau tends to cause the different areas to overlap, but I could put a sort on the pill on the Color shelf to get it to appropriately non-overlap.

       

      My question is whether this is at all effective in communicating information? An unstacked area chart clearly loses the part-to-whole relationship in the stacked area chart, yet it seems like it might better than an unstacked line chart at communicating relative proportions between the different dimensions. I've attached a workbook with some different views, and look forward to any feedback the community might have.

       

      Jonathan

        • 1. Re: Unstacked area chart - good idea or bad form?
          Andy Cotgreave

          I'd say that that is a dangerous way to build your chart I'd think that most users would still interpret the items as stacked. With stack marks off, you would be better off just drawing a line chart.  It also makes interaction with the chart really odd because it's nigh on impossible to properly select the individual marks.

           

          I recommend: avoid!

           

          Andy

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          • 2. Re: Unstacked area chart - good idea or bad form?
            Shawn Wallwork

            I agree with Andy (sort of). Not so much the 'dangerous' or 'nigh on impossible' but the probably best to 'avoid' (without the '!' ). The problem I have is that I disagree with your statement:

            An unstacked area chart clearly loses the part-to-whole relationship

             

            I thinks that is the crux of the problem, I don't think this is clear at all. The only real change when you flip between the two is the scale changes, but this can be easily missed, and misinterpreted/misunderstood. Traditionally area charts (or charts that look like area chart) usually illuminate the part-to-whole relationship, where as line chart (as Andy mentioned) tend to be used to illustrate relative relationships to each other. Substituting one for the other will I believe cause confusion, and require an explanation, which is never a good thing when doing a viz.

             

            But interesting exploration, Jonathan.

             

            --Shawn

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            • 3. Re: Unstacked area chart - good idea or bad form?
              Jonathan Drummey

              Thanks for the feedback! I'm dealing with users who are new to data visualization and are just starting to make use of interaction, so I was having a bit of internal debate about "beauty" vs. "accurate communication" since the expectations of what an area chart "should" be don't really exist (yet). Since area charts in the wider world are stacked, I'll be leaving them stacked so as to not create confusion.