This post should be taken a bit lightly but is nevertheless true.
Recently I bought an e-bike. You know, a bicycle with an electric motor that supports you. This e-bike, though a relatively simple (I.e. cheap) one, has some nice features:
– built in GPS tracking
– a SIM card in the frame somewhere to send your e-bike data over the air to a server owned by the manufacturer (I guess)
– other sensors that detect movement of some kind
So it comes with an app. Of course. Everything needs to be smart and connected to the internet nowadays.
The app shows me data about:
– what route I drove, using the GPS data and a map
– how many calories I burned
– how much CO2 I did not throw into the air as I took the bike and not the car
– average speed
For the above data I can see today, yesterday, last days, last month etc.
The sensors also emit signals that the app will receive and show me as notifications on my phone or watch, such as:
– whether movement was detected
– whether the bike has left a predetermined geofence
– whether the bike fell over
– whether the bike is moving faster than 50 kilometres an hour
Wow, great! Isn’t it?
Well, not all of it, because:
– the sensors can’t tell that it’s me moving the bike
– the sensors can’t tell that it’s me that fitted the bike to my car (hence the notification for faster than 50) and not someone you don’t know driving a white van and who isn’t the bike repairman either
– the sensors don’t know the difference between falling and a speed limiter bump that you drive over at about 20 km/h
As the bike is parked in a building with lots of concrete and other close by buildings, I also get a notification sometimes that the bike has left its geofence. Yesterday it did 13 km on its own. But I didn’t get a movement notification. In fact, the bike never moved at all. Nobody borrowed it. I was at work.
So that data is a little inaccurate…
Which brings me to the reporting part of that data in the app. It tells me I saved an amount of CO2. But compared to what? To a car it says on the help page. But what car? A Tesla doesn’t produce CO2 at all (apart from when you have a flat tire). Not very useful.
So my key points of this post are:
– is your sensor data trustworthy?
– is your reporting telling the right story?
– is your data lineage clear?
– do you know how your data relates to each other?
If the answer is no to most points, I wish you all the best interpreting your (big) data. You know where to find me to help out…