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Dashboard Data — Show TA’s Distribution

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As I have mentioned in my blog “Dashboard Data — Plan” the first thing I want to do is “Show each TA’s grade distribution vs. the whole distribution in the graph.” To do this I should see how to collect (maybe calculate) the data to be shown, namely the mark given by each TA to a submission. I have sent emails to Severin and Mike asking this question and thanks to their help I got some basic ideas about where to seek these data. If I have more questions about that, I will post another blog later as I start do the implementation.

But for now in this blog I want to discuss several ways to present the TA’s grade distribution. Please response in the comment which way do you prefer πŸ™‚

* Use Bluff.SideBar


  • Show all the TAs’ distribution in the same graph which makes it very convenient to compare them


  • According to my test things going to mess up when there are more than 3 TAs. The best case is when there are only 2 TAs and 3 is tolerable, but it will be very hard for the user to see the distribution when there are 4 TAs or more
  • Cannot compare each TA’s distribution vs. the whole distribution

* Use Bluff.SideStackedBar I


  • Show all the TAs’ distribution and the whole distribution in the same graph
  • Performance does not change when there are more TAs. According to my test the graph still looks good when there are 5 or 6 TAs (although I don’t think there will be that many TAs in an assignment ;))


  • Although all TAs distributions and the whole distribution are shown in the same graph, it seems harder for the user to compare each of the TA and the whole distribution

* Use Bluff.SideStackedBar II


  • Compare each TA vs. the whole distribution, thus making it’s easier to see each TA’s grade distribution out of the whole distribution


  • In fact what I expect in the above graph is yellow bars can be showed at he left side and the blue bars on the right side, but after I tried several times I cannot fine a way to change the order of these bars πŸ™
  • We can turn on the tooltips of Bluff, which allows you to hover the mouse over a data bar to see the name and value of the bar in a popup box next to the mouse. But if we hover the mouse over the blue bars the popup box will give us the sum number of other TAs’ other than the total number of students in this interval. (If we store the total number of the students in the blue bars the total length of the bar will not represent the actual number of the students, in fact TA1’s number will be counted twice)

* Use Bluff.Net


  • Show all the TAs’ distribution and the whole distribution in the same graph and it seems the best way for the user to compare each TA’s distribution as well as with the whole distribution


  • tooltips of Bluff can not be used in this kind of graph πŸ™

* Final Solution
Render each of the TA’s distribution and the whole distribution separately in different graphs.

I just omit the other two TAs’ graph but it’s just the same thing πŸ™‚ Following is the whole distribution.


  • Neatest graph and easiest to see


  • Hard for comparison
  • More graph’s needed

Written by Yansong

February 13th, 2011 at 7:23 pm

Posted in Uncategorized

3 Responses to 'Dashboard Data — Show TA’s Distribution'

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  1. Where are you planning on placing these graphs? If we put them in the dashboard, it might become a bit too congested and there might be too much information for the admin to see all at once. If we don’t mind the idea of having links to a different page (or maybe pop-up windows) for showing the more complicated graphs, this problem would be easily solved.

    You could build the graphs using the first method (which is in my opinion the most useful since it shows all the relevant information on one graph in a simple-to-understand format) only make the graphs big enough to fit as many TAs as needed. If you can assume that you only have one large graph on one page instead of a larger number of small graphs, then that makes this much easier.



    13 Feb 11 at 7:37 pm

  2. How about having an area graph, from 0 to wherever for each TA, and maybe some javascript to show/hide each TA/the combined?

    For me I think that would be the easiest to digest. For me, the best example of graphs that compare multiple things at multiple data points on the web I’ve seen is here:

    Cameron Gorrie

    14 Feb 11 at 12:28 am

  3. Awesome work πŸ™‚
    Would it be possible to have the possibility to choose one of these graphs instead of having only one ?

    Benjamin Vialle

    14 Feb 11 at 5:41 am

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