2 notes on data visualization

Written on 9 October 2019, 09:37pm

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  1. Know the limitations of pie charts: not so good for comparing values between themselves, but really good to compare relative to the 50% line
  2. Match your type of data with the right color scheme. There are 3 types of data: sequential, divergent and qualitative. The sequential color schemes help with ordered data. The divergent schemes use a neutral color the mid-range data and highly contrasting colors for the extremes. The qualitative schemes focus on creating visual differences between the sets of data.
Bar charts are better if you need to compare the values
But pie charts have their strengths when comparing to the 50% line
A sequential scheme. Colors range from light to dark, and are usually colorblind safe
A diverging scheme. Mid-range neutral color, highly contrasting extremes.
A qualitative, colorblind-safe scheme. It gets trickier if you need more than 4 colors. Each color need to scream “I’m different!



Random links #14

Written on 26 March 2019, 07:01pm

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Kano allows your kid to build their own computer and learn to code. It’s an amazing tool that will help your kids improve their digital skills.

Make your own computer. Then learn to code


Trypophobia is an aversion to the sight of irregular patterns or clusters of small holes, or bumps. Didn’t know this is really a thing…

Lego bumps


Glass vs plastic when it comes to bottled water

When glass is recycled it gets turned in to more glass. It can be recycled over and over and never lose its integrity.
Plastic bottles, however, are not recycled into plastic bottles. The plastic loses its integrity and needs to be turned into something different such as plastic lumber or carpet padding. Because of this, some people say that plastic isn’t truly recycled; it’s downcycled.
Every time a product is packaged in a plastic bottle, jar, or other container, it’s new plastic. All new resources went into making it. Glass jars, on the other hand, can be made from recycled glass. 



Protanomaly: a type of red-green color blindness in which the red cones do not detect enough red and are too sensitive to greens, yellows, and oranges.
As a result, greens, yellows, oranges, reds, and browns may appear similar, especially in low light. It can also be difficult to tell the difference between blues and purples, or pinks and grays. Red and black might be hard to tell apart, especially when red text is against a black background. Read more


How to Build a Successful Career in Information Security / Cybersecurity
Some great advice from Daniel Miessler:

  • learn to code
  • build your lab
  • build your portfolio of projects (make sure you own your data)
  • practice with bounties
  • get involved – contribute to open source projects
  • be active, engage in conversations
  • network with others
  • participate to conferences
  • find a mentor
  • get certified:
    CISSP is the closest thing to a standard baseline that our industry has. It’s actually better than a computer science degree in a lot of organizations
  • most importantly: have passion!

When I come across charts like this, this or this, my reaction is to point to obvious: that the information is unreadable by 1 in 12 men and in 1 in 200 women. Being one of them certainly helps to see the problem 🙂
Pointing it out is certainly good for raising awareness, but it’s not enough. Driving change is what ultimately matters. And the good news is, in most cases the change is really easy. So easy that I can resume it to two action points:

1. Don’t use color alone to convey meaning. Use icons, written content, and other visual elements to reinforce clear communication of the content.


2. Make sure there’s sufficient contrast between graph colors so people with color blindness can distinguish the colors.


That’s it! Seriously. Add some symbols to your chart bars and pick a colorblind-friendly palette. Implementing the two points above will make your data visualization efforts more inclusive. If you want to go the extra mile and show some empathy, then

Test what it’s like to view your designs through a color blindness simulator


The take away here is that “Designing for accessibility is not that hard“. As in the case of football, “This is not rocket science. It’s really about easy fixes“: