Bill Gates's 2013 Annual Letter

Bill Gates at the website of the Bill and Melinda Gates Foundation:

Over the holidays I read The Most Powerful Idea in the World, a brilliant chronicle by William Rosen of the many innovations it took to harness steam power. Among the most important were a new way to measure the energy output of engines and a micrometer dubbed the "Lord Chancellor," able to gauge tiny distances.

Such measuring tools, Rosen writes, allowed inventors to see if their incremental design changes led to the improvements-higher-quality parts, better performance, and less coal consumption-needed to build better engines. Innovations in steam power demonstrate a larger lesson: Without feedback from precise measurement, Rosen writes, invention is "doomed to be rare and erratic." With it, invention becomes "commonplace."

Of course, the work of our foundation is a world away from the making of steam engines. But in the past year I have been struck again and again by how important measurement is to improving the human condition. You can achieve amazing progress if you set a clear goal and find a measure that will drive progress toward that goal-in a feedback loop similar to the one Rosen describes. This may seem pretty basic, but it is amazing to me how often it is not done and how hard it is to get right.

More here.