3 Replies Latest reply on Jan 20, 2014 10:36 PM by Joshua Milligan

    # students enrolled in multiple trainings.

    Mallory Johnson

      I have a list of individuals (dimension) and a list of programs (dimension), and I'd like to create a bar chart showing how many individuals are enrolled in 1 program, 2 programs, 3 programs, (i.e. how can I show the number of students using multiple trainings?)

        • 1. Re: # students enrolled in multiple trainings.
          Phillip Burger

          Hi, Mallory. There are different ways to handle counts of this kind. But, we're going to need more detailed information to be able to help. 


          Is it proprietary or confidential data? If you can share the data, can you reply and attach a .twbx workbook to the thread? If you can't share the data, can you create sample data that matches the structure, type, nature, etc., of your data and use this in a .twbx that you can post?


          With an example, you'll probably get a couple of suggestions pretty quick. :-)

          • 2. Re: # students enrolled in multiple trainings.
            Joshua Milligan



            This is a pattern that I've run into a bit recently.  The shape of your data will matter.


            I've attached a workbook with 3 options for visualizing the data in the way you mentioned.  Each option has its benefits and drawbacks.




            Option 1 is a non-Cartesian plot where a single mark represents a single student.  Add them up and you'll get the total in 1 program, 2 programs, etc...


            Option 2 takes that concept to a bar chart.  If you were to click on one of the bars in option 2, you'd discover that it is really a stacked bar chart with individual bars of length = 1 stacked together to give you the right count.  There are actually 10 distinct marks in option 2.


            Option 3 uses some table calculations to give you a single bar for each program.  There are 3 marks in Option 3.



            Here are some considerations:

            Option 1:

            • Good if there is a small number that can be easily understood
            • May have some emotional impact (each of those is a student, not just a random mark)
            • Not so good if the exact number is important, especially if there are more than a few and I have to stop and count.  A discrete table calculation could be used to give an additional row header with the total count.
            • Can be used interactively in a dashboard because each mark has the dimensional value for a student that can be passed as an action filter.  However, to select all students that had a given number of programs, the user would need to click the row header or lasso select all the individual marks.


            Option 2:

            • Better than option 1 for allowing the reader to quickly understand the of total numeric values.
            • Worse than option 1 from an intuitive interactive user interface perspective.  A user expecting to click on the bar to filter in a dashboard might be surprised to find that only a segment of the bar is selected.  The user would have to click the row header or lasso select to get all the marks.


            Option 3:

            • Better from a UI perspective in that a single bar can be selected.  However, the bar contains only a single student identifier, not all the students that made up the count.  Therefore, it is almost impossible to use this one to initiate an action on a dashboard.



            Hopefully those give you some options to consider.




            • 3. Re: # students enrolled in multiple trainings.
              Joshua Milligan



              This question (in combination with some similar issues that came up recently) caused me to think through multiple options.  Here's a post with the three I listed above and one additional one using Sets that I like (as long as you don't want too many discrete values): Slicing by Aggregate | VizPainter