The dirty secret of data analytics: Culture of honest inquiry required

In the beginning there should have been a culture of honest inquiry. Instead there was the internal rate of return (IRR) — a polynomial formula for computing return on investment that only trained accountants could master. IRR defined business value in a single dimension of analysis: cash flows. The gods of accounting looked on it with favor, and so it was, theologically speaking, good. Then Dan Bricklin invented the electronic spreadsheet. Like Prometheus bringing fire to we mere mortals, Bricklin and his spreadsheet let all humanity calculate IRRs for ourselves — and once anyone could compute IRRs for themselves, they did. The problem? Managers quickly figured out how to do more than compute it. They learned to adjust their assumptions — poking, prodding, and tweaking parameters — until their IRR generators infallibly arrived at the answer they wanted.