Good models are discovered

A few weeks ago Philip Wadler said a few interesting things in his keynote Propositions as Types, which he delivered at LambdaDays conference (really great conference, check it out!). The talk was about functional programming, and how its underlying principles were “discovered” independently by various people. I’m sure you know more examples of this “coincidence”, the history of science and human invention is full of them.

The most valuable takeaway for me was the distinction between things that are “discovered” vs things that are “invented”. Things are discovered when their time comes, when all the pre-requisite work is in place, when somebody finally connects the dots. The dots have always been there, though, just hidden. That’s why many people can come to similar conclusions independently using different tools. The representation might be different, but the conclusions, the essence of the discovery are the same.

That is very different from inventing things, which is unnatural, forced, and even if it solves the problem just feels wrong and nasty.

I think the same is true for models and domains.

It doesn’t matter how you reach your conclusions, how many iterations it took you, how many times you re-wrote that piece of code. Maybe you organized workshops, maybe talked with experts over a cup or coffee, or maybe the crucial insight was inspired by an email exchange.

You look back and you’re wondering why you didn’t notice that from the very beginning. It’s just so obvious! Most of the time it’s not even a very complicated thing, it’s just “common sense”.

The main challenge is that things look obvious only when you look back. You can’t connect the dots looking forward. Only when you look back you KNOW that what you came up with is right. Maybe it’ll change in the future, who knows, but it’s right for the time being, for the current context, for the current problem.

For me the most interesting insights came when something didn’t feel right. Very often I couldn’t explain what was wrong with the existing model, at least not at first. But I didn’t let it go, I was a real PITA (usually just for myself) and looked around for answers.

After trying out a few different approaches (even if only on a piece of paper) the differences between models became noticeable. One was simpler and cleaner. The other didn’t explicitly represent an important concept. Yet another had too much noise, some concepts were unimportant in this context and should be dropped.

In software we can represent the same model in multiple ways in code. As long as the underlying concepts, business rules are the same, invariants are honoured, and business goal is achieved, then I don’t see a problem with that. And those important insights could be discovered independently by various developers working on the same project. I know that many people feel differently, but I’m one of those people who simply don’t care about “tabs vs spaces” and don’t have favourite text editor.

It’s been a while since my partner came up with a crazy idea of writing our own Expenses Tracking App. But now and then we still are not sure how could we didn’t see all those obvious things from the very beginning. Even worse, we’re not sure how exactly we did discover them. But we know they’re right, because they fit perfectly to what we want out of this app.

The good news is that if good models are discovered then eventually we’ll all find them if we persist in the search. All it takes is a lot of patience, good listening skills and never being satisfied with the first model that comes to mind… or second, or tenth 🙂

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