Design vs Reason?

I was pointed to a very interesting blog post by a designer who quit his job at Google.

Remove all subjectivity and just look at the data. Data in your favor? Ok, launch it. Data shows negative effects? Back to the drawing board. And that data eventually becomes a crutch for every decision, paralyzing the company and preventing it from making any daring design decisions.

The whole point of experimenting is that you can make daring decisions. Try it, measure it, and you'll know if it works. E.g. when Amazon decided to launch product recommendations: the management was against it. They were afraid that customers might be distracted from checking out. Luckily for Amazon subjective opinions were not the ultimate decision factor.

On the other hand, if you have a product that's used by many millions every day you might need to limit the freedom of experiments. It's not the fault of the data driven decision process but rather the fact that millions of users can get very annoyed if you are constantly changing the design completely.

Yes, it’s true that a team at Google couldn’t decide between two blues, so they’re testing 41 shades between each blue to see which one performs better. I had a recent debate over whether a border should be 3, 4 or 5 pixels wide, and was asked to prove my case. I can’t operate in an environment like that. I’ve grown tired of debating such miniscule design decisions.

I’m surprised they tested so many shades of blue. Maybe the engineers were trying to resolve some dispute between designers? I wouldn't be surprised if the data showed that it doesn't matter which shade you choose. And maybe the conclusion was not to bother too much about such design details in the future? There’s a lot to be learned from such experiments even if there is no clear winner. If you have a framework setup to run such an experiment quickly, why not do it? Which designer wouldn't like to know that the new design is helping the company succeed?

The 3 vs 5px example sounds odd to me. 5 is 70% bigger than 3. How’s that minuscule? Google’s design decisions affect millions. I’m very glad that they carefully check any changes they make.