February 12, 2021

Be Explicit

We’ve probably all experienced looking at a flashcard, saying to yourself “I know the answer”, then moving on to the next card. However if you were forced to actually write down the answer or say it out loud, could you have? Knowing you know the answer and actually retrieving the answer are two different things. We take this a step further when we overestimate the number of people who share our ideas, known as the false consensus effect.

These types of things crop up all of the time when we’re building things, and especially when we’re building things together. We make assumptions about how much we know about our part of the work. We make further assumptions that we agree on what the integrated end result should look like. Eventually we actually start building the thing and reality sets in, causing us to make changes where our assumptions were poor. Then during integration we all realize how little we understood each other’s ideas all along. All of this causes rework when it’s most expensive.

In these cases the adage “a picture is worth a thousand words” holds true. Drawing a flowchart, building a sequence diagram, or even role-playing as the systems talking to each other can help surface the assumptions you are each making about your system, the other system, and the boundary between them. This doesn’t mean you need to get into the details and the weeds of what the other person is doing (black box can still be appropriate).

Rather than end with some boring “bridges that don’t meet in the middle are bad” paragraph, I’ll leave you with the Tintagel Bridge, one of many that are designed to not meet in the middle. Because every rule has exceptions.

© Eric Biven 2021