Bob Marshall posted on Twitter:

I replied with:

and he replied:

In 1956, George A. Miller wrote a paper arguing that the conscious mind, the part that contains our inner voice and that does the reasoning processes, can handle 7 ± 2 items at a time. My view is that, in order to be able to function within these constraints, we learn to group similar things together so that they take up less processing space.

For example, if I want to remember a six digit number, it might be easier for me to remember it as 3 two digit numbers than as 6 individual numbers. Very familiar numbers, such as the phone number of my parents only take up one space.

It’s like I’m carrying a fixed number of boxes, all of which are the same size, but in which I can store things that (in my own mind) are grouped together.

One thing I’ve noticed though, is that I begin to speak of the ideas inside in terms of the labels that I’ve added to the boxes. In terms of hard facts, like numbers or addresses, this doesn’t really make much difference, however, when the ideas and opinions in the boxes are much more subjective, this can lead to confusion and disagreements (or sometimes, vigourous agreement 🙂 )

For example, imagine that I am moving house and packing my belongings into boxes. In one box, I pack the contents of the fridge and because the fridge is in the kitchen, I label the box “Kitchen Stuff”.

I say to the removals people, “The box labelled ‘Kitchen Stuff’ has to be moved quickly. It’s very important that this box is moved as fast as possible”.

The removals people reply “You’re insane. Boxes labelled ‘Kitchen Stuff’ have to be moved carefully, and that means that we have to take it slow”

“No,” I say, “this box has to be moved quickly. If you move it slowly the contents will be ruined”

“No,” they say, “if we move it quickly, the contents will break. We must move it slowly and carefully”

I open the box and show them the contents and they understand. “Oh, it’s fridge stuff. Why didn’t you say so? When you said ‘Kitchen Stuff’ we assumed that you meant plates and glasses”

When we put labels on things in the boxes, it becomes much quicker for us to talk in terms of the labels. However, although we may have boxes labelled in a similar way, that does not mean that the contents are the same.

The box in my mind labelled “Scrum” may match a great deal of the contents of the box that you have labelled “XP” or that someone else has labelled “Lean”. The good thing about these boxes in my mind is that I can have an object appear in more than one of them. I might even place these three boxes into another box labelled “Common sense” (although I strongly suspect that the box with that particular label is guaranteed to be vastly different between every person)

As with my conversation with the removals men, I can get into a heated discussion with someone if we’re talking in terms of the labels on our boxes.

“XP is this, this and this”.

“No, that’s Scrum!”

The only way we can truly reach an understanding is if we recognise that we’re arguing over a label, and open our boxes to compare contents.

Sometimes, I even forget what I have stored in my boxes. I might only be talking about my memory of the things that I think I stored in the box. Opening the box and reviewing the contents, especially when someone else is doing the same, can help me to find new ways of categorising the ideas within. We might even find a common ground and start a revolution.

So, next time we don’t see eye to eye about the memories of the contents of our boxes, remind me “I’ll show you mine, if you show me yours”