Intuition Versus Evidence

evidenceDouglas Bowman recently announced he was leaving Google after three years as visual design lead.  According to Bowman, the reason was Google’s relentless drive for evidence-based design, which collided with his drive for ground-breaking design:

When a company is filled with engineers, it turns to engineering to solve problems. Reduce each decision to a simple logic problem. 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.

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 minuscule design decisions. There are more exciting design problems in this world to tackle.

We’ve had similar discussions at Express Scripts about the role of intuition versus evidence (although as far as I know, it’s never led to the point of someone leaving the company).  It’s a genuinely interesting discussion.  How much evidence is needed to make a decision?  When is intuition good enough?

It’s very useful to think of a decision as an irrevocable allocation of resources.  Irrevocable seems like a strong word, but it’s pretty helpful.  If the decision can be completely undone, it’s not really a very interesting decision; you can try lots of different options and then stick with the one that works best.

Decisions get interesting when the stakes are high, there’s lots of uncertainty, and they are costly to undo (that’s another way of saying that some of the resources being allocated irrevocably). Obviously, it’s these decisions for which we would like lots of evidence, and the highest fidelity predictions of what the world might look like under each of the options being considered.  (For example, if airlines had been able to predict fuel price swings in 2008, they could have performed much better financially by buying futures contracts to minimize their exposure.)

Paradoxically, the bigger and more uncertain a decision, the less frequent the opportunity to gather evidence to inform the decisions we make.  This doesn’t mean we must resort to intuition alone; very careful articulation of each point of view can reveal whether differences about the best course of action result from differences in information, differences in belief about what information means, differences in value (e.g., risk tolerance), or simple errors in logic.

When do you use intuition?  When do you turn to evidence?

(Note: this entry originally appeared at

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