Explain "validated learning" in your own words, detailing *how* it functions as a mechanism to address the "extreme uncertainty" inherent in new ventures and their primary mission.

Synthesized answer

Validated learning is a central premise of The Lean Startup movement that involves getting continuous feedback from customers [1]. This mechanism addresses the extreme uncertainty inherent in new ventures by enabling companies to shift directions or alter their plans inch by inch, minute by minute [1].

Instead of relying on an elaborate business plan and a product-centric approach, validated learning prioritizes continuously testing a vision with customers and making constant adjustments [1]. This approach helps startups avoid building something nobody wants, which is a common reason for failure [1]. The primary mission of new ventures is to discover what customers will ultimately buy, and validated learning is the way to achieve this [1].

Synthesized from the book passages below. Chat with the book on Feynman for follow-up.