Innovate like Google

Watching this conversation between Tom Davenport and Paul Michelman, I came to think about this extract from page 120 the book "The Future of Management" by Gary Hamel: “Build a “just try it” culture – emphasize “test and learn” instead of “plan and execute”."

Thinking about the companies, you work for, what is more important: “Test and learn” or “plan and execute”? If you have the possibility, please explain why.