Back in, I think it was 2009, at the Lean Software Systems Conference in Long Beach California, I had the opportunity to have a brief conversation in the hallway with Barry Boehm. For those of you who don’t know the name, you may still be familiar with his most widely spread idea The Cost of Change Curve.

It looks something like this:


It’s most commonly used (in my experience) as a justification for Why We Must Use Waterfall.[1]

I mean, if you look at it, it’s obvious right? You want to get those requirements right! No good finding out that you’ve build the wrong thing once it gets into production! Waaay too expensive.

I gently called Barry on this; kind of / sort of blaming him for arming legions of Waterfall Enthusiasts with a deadly weapon of science and reason. After all you can talk Value until you’re blue in the face, but nobody wants their costs to go up – at least not by that much.

A strange sad expression passed briefly across Barry’s face as he asked me “What else could it mean?”

If you open you mind and look carefully at the chart again- it might just switch from being a mandate to becoming a warning.

A warning, that if you use a Waterfall Style Method, your cost of change WILL go up exponentially towards the end of the project. As it turns out, Waterfall is the cause (and for many people the cure)[2] of and for the Cost of Change Curve.

What had happened was that people (lots of people) had misunderstood the message.

I started to think about what else people had misunderstood (and as a result typically misused) in the world of methods and processes – and came up with what I called “The Misunderstandability Index”. Reflecting on the fact that (for example) Scrum rated very highly on the Misunderstandability Index, whilst the Kanban Method (again for example) ranked a great deal lower.[3]

I largely kept this idea to myself and a few colleagues until a few years later, when I was having lively conversation with Yuval Yeret at the Speakers Dinner after LKNA in Chicago.

We had been having a discussion around whether teams that had utterly failed to grasp Scrum could in fact do Kanban well, or at all. And additionally that it seemed often to be the case that Teams working in environments that were the least suited to Scrum, wanted to to do it the most.

In order to illustrate a point I brought up my story about Barry and my Misunderstandability Index. Yuval was excited, and asked me to publish something on Misunderstanability.

It’s about ease, not difficulty, in cognition

One key factor I’ve come to understand about misunderstanabilability over the last few years is that it’s about ease in cognition. Not difficulty.

Another example may help. At the same conference, Donald Reinertsen was also speaking. And he was speaking on dense economic models. Lots of maths, lots of big words. The stuff he’s famous for. Good stuff, but hard going.

In that room there was very little misunderstanding going on; largely because there was not a great deal of understanding going on. For many people it was all just too hard – but they knew it was too hard.

Misunderstanding occurs when you think you grasp something, but in fact you haven’t.[4]

It brings to mind the Twain quote:

It ain't what you don't know that gets you into trouble.
It's what you know for sure that just ain't so.

Misunderstanabilability is therefore the natural pre-disposition that an idea has towards being misunderstood.[5]

Ideas are not sufficient. If we’re constantly having to tell clients that “it’s not working because they’re doing it wrong” then maybe it’s time we stopped lecturing and started examining the level of misunderstandabilability in our messages.

  1. I personally first encountered the curve, in Project Management classes at University  ↩

  2. This is of course a cure in the same sense of the word that staying drunk is a “cure” for a hangover.  ↩

  3. The lower the score, the more the intent behind your idea is understood by others.  ↩

  4. In psychological terms, you’ve made a substitution in the first instance and are subject to confirmation bias in the second instance. It’s the second part that gets us into trouble, because once we have misunderstood, it’s very hard to suddenly start understanding.  ↩

  5. And in this way I would like to make a clear distinction between “misleading” which implies an intent to deceive and something that’s simply high in “misunderstandabilability” meaning that it’s highly susceptable to misinterpretation.  ↩

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