I never considered colour-blindness before, so thanks for those links, Job. On Wed, 24 May 2017, 11:36 Emile Aben, <emile.aben@ripe.net> wrote:
Hi Job,
Thanks for your detailed feedback. We'll take that into account in further developments around the tool. Remember this is a prototype (code is available at: https://github.com/emileaben/ixp-country-jedi ). If you have a colour scheme that you think would work better for all cases, you can submit a pull request there. Or we can work together on improving this in a mini-code-sprint sometime soon?
Couloring IXPs as green was done because this tool was initially developed in an IXP context; it was presented at EURO-IX and Netnod meetings, and my understanding was that the IXPs would favour paths going over the IXP. I think you are correct in pointing out that this is not necessarily the right thing to do in all contexts.
There is already work underway to look at direct vs. indirect interconnections in the tool. Our research intern Petros Gkigkis is going to show a sneak preview of that at the upcoming GRNOG meeting ( https://www.grnog.gr/?lang=en ) this Friday.
And of course there will be RIPE Labs articles about further developments like this. So keep an eye out at https://labs.ripe.net :)
kind regards, Emile Aben RIPE NCC
On 24/05/17 15:15, Job Snijders wrote:
Hi all,
TL;DR - red/green color palettes should be avoided in data visualiations, please pick something else!
Yesterday I saw Christian Teuschel present on the "Jedi" tool at SINOG, and two things stood out:
A) the data visualisations do not attempt to accomodate for people who are color blind, in fact, the worst colors possible were picked
B) by using using common traffic light colors (green, orange, red) an implicit judgement is made on the meaning of the data (traffic crossing an internet exchange was seemingly favored over private peering)
To point (A) - red–green color blindness which affect a substantial portion of the human population. In the US, about 7 percent of the male population (or about 10.5 million men) and 0.4 percent of the female population either cannot distinguish red from green, or see red and green differently from how others do (Howard Hughes Medical Institute, 2006). There are quite some pointers as to how to design color palettes which accomodate everyone.
http://www.somersault1824.com/tips-for-designing-scientific-figures-for-colo...
http://blog.usabilla.com/how-to-design-for-color-blindness/
B) As I understand the "Jedi" tool, it shows matrixes of what traffic between atlas probes leaves the country, and what traffic remains within the country - offering insight into a reflection on a country's internal routing arrangements. I'm a big fan of keeping local traffic local, so the tool certainly has value.
However, the tool displays traffic which passes over an IXP within the country as green, and traffic that says within the country but didn't cross an IXP as "orange". Since the majority of internet traffic flows over direct, private interconnections between ASNs, signifying that traffic as "orange", has the potential to be taken as a "wrong", rather then as an arbitrary datapoint. I suggest that the Jedi tool either uses the same color for ixp and non-ixp "within country" traffic (and perhaps a small icon is used to signify the additional data attribute that an IXP was observed in the traceroute), or that the jedi tool uses entirely arbitrary colors that have no inherent meaning like the traffic light colors do.
Kind regards,
Job