Last year at the Agile Testing Days 2013 in Potsdam there was a great presentation by David Evans about “Visualizing Quality”. It was about different ways of presenting data. One of the examples was the London Underground map.
Lancaster Gate to Paddington
Let’s say you are a tourist in London standing just outside Lancaster Gate Underground station on the Central Line (red) and your destination is Paddington station. Most tourists using a tube map choose the following way:
- Get on the Central Line (red) at Lancaster Gate
- After two stops at Notting Hill Gate change to Circle Line (yellow) or District Line (green)
- Go further 2 stops to your destination – Paddington Station.
Having a look at the London Underground map it is a valid choice. It absolutely makes sense to choose this option by the given representation of the data.
However it is not the only possible way. Of course you can use a different approach on the Underground itself. But you can also use a much shorter way. You can walk it. If we have a look at the second image (Google maps) we can clearly see that it is just a 10 minute walk from Lancaster Gate to Paddington and you are probably faster than waiting for a train and changing to a different line.
What we can see here are two different ways of presenting data. The London Underground map was designed to show you all the lines and stops in a way that makes it easy to navigate through the public transportation network. Distances on this map often don’t concur with reality. Google maps in contrast shows us a different view for a different purpose.
For me this is a good example regarding the presentation of data. We can collect a lot of metrics on a project which in some cases can be important. What we should mind when we collect metrics is:
- the way we present them
- the audience the metrics are for
- the context and usage of the metrics
It’s not all about gathering data – it’s also about presenting them.