Blind To Your Own Assumptions

Whether inventing new technologies, designing new products, or solving manufacturing problems, it’s important to understand assumptions. Assumptions shape the technical approach and focus thinking on what is considered (assumed) most important. Blindness to assumptions is all around us and is a real reason for concern.  And the kicker, the most dangerous ones are also the most difficult to see – your own assumptions. What techniques or processes can we use to ferret out our own implicit assumptions?

By definition, implicit assumptions are made without formalization, they’re not explicit. Unknowingly, fertile design space can be walled off. Like the archeologist digging on the wrong side of they pyramid, dig all he wants, he won’t find the treasure because it isn’t there. Also with implicit assumptions, precious time and energy can be wasted solving the wrong problem. Like the auto mechanic who replaced the wrong part, the real problem remains. Both scenarios can create severe consequences for a product development project.  (NOTE: the notion of implicit assumptions is closely related to the notion of intellectual  inertia.  See Categories – Intellectual Inertia for a detailed treatment.)

Now the tough part. How to identify your own implicit assumptions? When at their best, the halves of our brains play nicely together, but never does either side rise to the level of omnipotence. It’s impossible to stand outside ourselves and watch us make implicit assumptions. We don’t work that way. We need some techniques.

Narrow, narrow, narrow. The probability of making implicit assumptions decreases when the conflict domain is narrowed.

Narrow in space and time to make the conflict domain small and assumptions are reduced.

Narrow the conflict domain in space – narrow to two elements of the design that aren’t getting along. Not three elements – that’s one too many, but two. Narrow further and make sure the two conflicting elements are in direct physical contact, with nothing in between. Narrow further and define where they touch. Get small, really small, so small the direct contact is all you see. Narrowing in space reduces space-based assumptions.

Narrow the conflict domain in time – break it into three time domains: pre-conflict time, conflict time, post-conflict time. This is a foreign idea, but a powerful one. Solutions are different in the three time domains. The conflict can be prevented before it happens in the pre-conflict time, conflict can be dealt with while it’s happening (usually a short time) in the conflict time, and ramifications of the conflict can be cleaned up in the post-conflict time. Narrowing in time reduces time-based assumptions.

Assumptions narrow even further when the conflict domain is narrowed in time and space together, limiting them to the where and when of the conflict. Like the intersection of two overlapping circles, the conflict domain is sharply narrowed at the intersection of space and time – a small space over a short time.

It’s best to create a picture of the conflict domain to understand it in space and time. Below (click to enlarge) is an example where abrasives (brown) in a stream of water (light blue) flow through a hole in a metal plate (gray) creating wear of the sidewall (in red). Pre-conflict time is before the abrasive particles enter the hole from the top; conflict time is while the particles contact the sidewall (conflict domain in red); post-conflict time is after the particles leave the hole. Only the right side of the metal place is shown to focus on the conflict domain. There is no conflict where the abrasive particles do not touch the sidewall.

blind to assumptions conflict domain

Even if your radar is up and running, assumptions are tough to see – they’re translucent at best. But the techniques can help, though they’re difficult and uncomfortable, especially at first.  But that’s the point.  The techniques force you to argue with yourself over what you know and what you think you know.  For a good start, try identify the two elements of the design that are not getting along, and make sure they’re in direct physical contact. If you’re looking for more of a challenge, try to draw a picture of the conflict domain. Your assumptions don’t stand a chance.

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Mike Shipulski Mike Shipulski
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