[tor-bugs] #21882 [Metrics/Consensus Health]: Graph for number of relays that bwauths decided the median for

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#21882: Graph for number of relays that bwauths decided the median for
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 Reporter:  Sebastian                 |          Owner:  tom
     Type:  defect                    |         Status:  new
 Priority:  Medium                    |      Milestone:
Component:  Metrics/Consensus Health  |        Version:
 Severity:  Normal                    |     Resolution:
 Keywords:                            |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Comment (by karsten):

 Sebastian, I agree that it would be interesting to see how severe the
 variation was.  One thing I'm worried about is that we're trying to put
 too much information into one poor graph, which is why I want to suggest a
 simplification: we drop the distinction between "shared" and "exclusive"
 and also drop the "unmeasured" area, and therefore we add multiple areas
 for how much above or below the measured value was.  Reasons:

  - The distinction between "shared" and "exclusive" is rather artifical
 and is just the result of rounding small integers.  I didn't look at the
 data, but I would expect most "shared" measurements to be in the 10s or
 20s, where measurements are really something like 19.5, 20.4, and 20.9,
 rounded to 19, 20, and 20.  Do we care that those two 20s are the same and
 the 19 is not?

  - Dropping the "unmeasured" area would not cause that information to be
 lost, it would just be displayed differently: the total colored area would
 be lower for an authority.  We could just say that we're displaying
 measured relays only.  (If this is critical information, we could paint
 that are dark gray or something, but that makes the graph with the next
 suggestion a bit less intuitive.)

  - These two simplifications would permit us to use a "diverging" color
 schemes here, like
 [http://colorbrewer2.org/#type=diverging&scheme=RdBu&n=9 this one], where
 we'd use different reds for values above and different blues for values
 below.  We could still use classes like "at most 10% above", "at most 50%
 above", "more than 50% above".  Or we could use fewer classes like the two
 you suggest.

 I can make a sample graph if needed.  Though I'd like to hear first
 whether the graph described above would still be useful.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21882#comment:8>
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