Random links #11

Written on 14 February 2019, 11:03am

Tagged with: , , ,

  1. The misinterpretation of the Mehrabian theory
  2. The four stages of competence
  3. How to avoid death by PowerPoint

There is a theory attributed to Albert Mehrabian according to which the non-verbal communication (NVC) accounts for 93% of the overall communication. In other words, what you say has virtually no importance, while how you say it (the tone and the body language) is almost everything.
Without negating the importance of the NVC, it is quite clear that the Mehrabian theory only applies in limited cases. In fact, the theory itself states that it applies only to communication about feelings or attitudes. This video does a pretty good job to debunk the 7% myth.
That being said, I strongly believe that the delivery can make or break a presentation. Take the same content and have it presented by two random people and you’ll understand what I mean.

The learning circle (or the 4 stages of competence) is a very useful way to visualize the learning process:

The circle of learning. Image from impower.co.uk

Finally, a presentation about how you should do your presentationsÂ đŸ™‚ If you only have time to watch one video about improving your presentation skills, it should be this one:


David Phillips has become the leading Swedish figurehead in the art of making presentations

In a nutshell, keep in mind the following simple principles when working on your next slides:

  • use a dark background
  • add a single message per slide
  • use keywords or images, not sentences
  • use size to highlight the important elements
  • don’t use more than 5 objects per slide

That being said, you can deviate from the principles above in case you don’t present your slides on a stage in front of an audience. A slide like the one below could still make sense during a meeting where you brainstorm with other technical colleagues:

Target to your audience: if you’re talking to a bunch of other nerds, a slide like this can make sense and don’t bore anyone to death. But never show this on a stage!

The importance of visualization in problem solving

Written on 10 February 2019, 12:36pm

Tagged with: , ,

This weekend I thought about the flashlight and 8 batteries riddle:

You have a flashlight that works with 2 batteries. You also have 8 batteries, of which 4 are empty and the other 4 are full. There is no way to tell which battery is empty and which one is full, but you can put 2 batteries in the flashlights. If both of them are full, the flashlight will turn on.

What is the minimum number of tries that will guarantee that the flashlight will turn on?

At first, I explored the possible combinations, then I considered playing with probability trees. But then I put this on paper, and soon, things became much clearer. I represented the batteries with dots, and the tries with lines, and instead of playing with abstract concepts, I started to play with lines and dots:

Dots and lines

First I found a solution that would try 7 combinations, and would guarantee that the 8th was correct:

8 lines, guaranteed to work. But could it be better?

But somehow I knew that the solution had to be 7 tries, not 8. So I kept moving the lines and connecting the dots until the bulb lit (pun intended):

The solution: it had to be symmetric…

No matter where the 8th full battery is, there will be a line connecting it with another full battery. (You can also find a video here).

This shows the importance of visualizing your problem before being able to come up with the answer. I am using a Moleskine notebook and a Baron Fig Squire pen (some say it’s the best pen in the world đŸ™‚ ).