A lot of our initial conversations with clients start with some version of the following: “We really don’t know how to prove that we do x. We know that we see that change day to day, but we don’t have the data to prove that we caused that change.” The key word in this request, of course, is “caused.” Often, organizations feel pressured to demonstrate that their intervention was the sole cause of an observed change. Even when funders or stakeholders aren’t requesting that directly, it’s often assumed that “proving” that your intervention caused an observed change is still the “holy grail” of evaluation.