7 Replies Latest reply on Jun 20, 2017 11:51 AM by Katie Poznanski-Ring

    How do I compare the same statistic filtered on different fields?

      Hi,

       

      I am new to Tableau and evaluating it for use on a certain project.  So far I have not had much luck figuring out how to do what I want.

       

      The Data

       

      I have a table of course sections (instances of courses for a given semester and time), the average gpa for that course section, along with the department and college the course is associated with.

       

      The Chart

       

      What I need to make is something like this:

      IMG_20120627_093842.jpg

      So, for a given course, I want to show that course's gpa (a single value), compared to it's department and college's average gpa (filtered by two different columns), along with the average gpa of the entire University (essentially the average of all the records).

       

      I haven't had much success in any of the ways I have attempted it...

       

      Is it possible to compare the same statistic filtered differently against each other?

       

      Thanks for any help you can give.

       

      Shaun

        • 1. Re: How do I compare the same statistic filtered on different fields?

          Hey Shaun,

           

          To clarify your question, you are wanting to compare GPAs using at least 4 different filters?

          1) Course

          2) Dept

          3) College

          4) University

           

          If possible, sample data always helps, but it seems to me that all you have to do is create 4 different worksheets with local filters and put them in a dashboard.  Then you can set a global filter to change which course you are viewing on the dashboard.  Just make sure that the bar graphs are formatted correctly and are uniform 0-4.0 marked every .5 GPA.  Will that solve your situation or am I not understanding the question?

           

          --Jeff

          1 of 1 people found this helpful
          • 2. Re: How do I compare the same statistic filtered on different fields?
            Tracy Rodgers

            Hi Shaun,

             

            I have attached a sample workbook with instructions that I believe will give the desired outcome. Hope this helps!

             

            -Tracy

            • 3. Re: How do I compare the same statistic filtered on different fields?

              Hey Jeff,

               

              It sounds like you are following what I was trying to do.  I should have posted a little excel spreadsheet to help out.

               

              If I understand correctly, that is the direction I was going, but I thought it started to get a little tricky to use and didn't look as good spread across the four different charts.

               

              Thanks for the quick response.

              • 4. Re: How do I compare the same statistic filtered on different fields?

                Hey Tracy,

                 

                Thanks for the very thorough and quick response.  It does help quite a bit. I'll have to look into those table calculations to see what they do, but it looks to be almost exactly what I want.

                 

                The one thing I did notice, though, is that the GPA for the department always matches the course GPA.  For instance, selecting course C or D, I think, should show a Department gpa of 3.4 (instead of 3.2 for C and 3.6 for D).

                 

                What I ended up doing (I guess I should have thought of this quicker), was just adding some new data sources that are custom sql queries. I added one data source for Department GPA that was just the average gpa grouped by department, one for College GPA that was the average gpa grouped by College, and the same idea for University.

                 

                This made the workbook pretty straight forward and probably the direction I'll work toward until I can figure out how table calculations work (maybe it's easy?).

                 

                Thanks again for the help.

                • 5. Re: How do I compare the same statistic filtered on different fields?
                  Tony Russo

                  Shaun: I've been trying to wrap my head around similar problems/calculations, so I jumped in and was exploring Tracy's response. I was able to match Sheet one by editing the GPA by departments Table Calculation to "advanced", compute using the four fields in order, at the level of "Course" and restarting every "Department". I'm not sure how this fits into Tracy's approach, but if you can wrap your head around the table calcs, it seems would be a cleaner way to attack the problem instead of separate datasources.

                  1 of 1 people found this helpful
                  • 6. Re: How do I compare the same statistic filtered on different fields?

                    Hey Tony,

                     

                    Thanks for the follow up.  I followed your instructions and was also able to get Tracy's worksheet to work like I expected.  One funny thing is that when I was looking at it yesterday I didn't even notice there were two worksheets.

                     

                    I think you are right... I'm going to read about table calculations and try to follow this same pattern for my project.

                     

                    Thanks for the help.

                    • 7. Re: How do I compare the same statistic filtered on different fields?
                      Katie Poznanski-Ring

                      Hi @Tracy,

                       

                      Your solution to Shaun's problem is close to answering a problem I've been wrestling with about course evaluations as well, and I was hoping you might be able to help me structure my data appropriately to produce the below table:course eval eg sheet.JPG

                       

                      Where you have a University-College-Department-Course hierarchy in Sheet 1, I need to display results for each course taught by an instructor compared to the department aggregate compared to the college aggregate, as pictured. We've been producing these tables in Excel, and I want to move us away from that and into Tableau reporting. Essentially, each instructor receives a summary sheet displaying their personal course evaluation results (e.g. Course 1 and Course 2) with department and college overall aggregates for comparison purposes; I can easily make the course-dept-college distinctions in Excel, but am stuck on how to achieve this in Tableau.

                       

                      Your help would be much appreciated!

                      Katie