Last week was Halloween and of course we went trick-or-treating with our three kids which resulted in piles of sweets in the living room. Powered by the sugar, the kids would stay up late to count their harvest and while I was observing them at it, I was wondering if it possible to explain the MapReduce paradigm to them, or even better: doing MapReduce with them.
Now, it turns out that Halloween and counting kinds of sweets are a perfect setup. Have a look at the following:
So, the goal was to figure how many sweets of a certain kind (like, Twix) we now have available overall, for consumption.
We started off with every child having her or his pile of sweets in front of them. Now, in the first step I’d ask the kids to shout how many of the sweet X they have in their own pile. So one kid would go like I’ve got 4 fizzers, etc. … and then we’d gather all the same sweets and their respective counts together. Second, we’d add up the individual counts for each kind of sweet which would give us the desired result: number of X in total.
Lesson learned: MapReduce is a child’s play. Making kids sharing sweets is certainly not – believe me, I speak out of experience ;)