The Truth Curve and the Build Curve

This post is by Giff Constable from

In my two books on testing new business ideas, I have a diagram called the “truth curve”. I often get credit for a variation that my friends Jeff Gothelf and Jeff Patton created, but their diagram makes a different, equally valuable point. I’m going to take the liberty of calling their graph the “build curve”. Let’s look at them both.

The Truth Curve

The truth curve asks, “can I believe what I am learning?”

When you are in your own head “inside the building”, you are in fantasy land. However, real truth is in the upper right: your product is live and people are buying or not buying, using or not using, retaining or not retaining. Your data is your proof. However, you can’t wait that long to test your ideas or you will make too many mistakes, waste too much time, and have needlessly costly failures.

That concept is elegantly shown in a visualization Janice Fraser sketched for me on a napkin a decade ago.

If you look at the Truth Curve, we start by using low-lift tactics like interviewing customers and running small experiments, and we work our way to bigger, more experiential experiments where you study someone’s behavior with some kind of simulation of your intended experience.

We start with lightweight methods because they are quick to bring us insights, but the believability of those methods is weaker. You can’t validate an idea with those methods. You need to apply your judgement and retain a healthy skepticism (Read more...)