The couple has learned to be farmers by trial and error.

"I think they're still just feeling their way through this by trial and error," the person said.

By trial and error, they learned to judge how much light was enough.

The problem was, they did their work by trial and error.

You'd have to find out by trial and taste or measurement how much.

So he had to do it by trial and error.

They did it by trial and error, over 1,000 years.

By trial, she has learned her limitations: three services in one day are too many.

Most of my learning has been by trial and error.

Well, they sure won't hit on that by trial and error.