The importance of a focus on disconfirmation

Here's a lesson from John Sterman's Business Dynamics: Systems Thinking and Modeling for a Complex World section 1.3.7: we gain little to no new insight by observing cases where data supports our hypotheses. We gain much from testing cases where data might disconfirm our hypotheses.

For more on that, see Raymond Nickerson's Confirmation Bias: A Ubiquitous Phenomenon in Many Guises, Bob Dick's Rigour and relevance in action research, the Skeptic's Dictionary entry on confirmation bias, Wikipedia's entry on the same subject, or one of my prior essays on skepticism.