A well-known parable describes a policeman who finds a drunkard searching for his keys under a streetlamp. The policeman asks where the man dropped them. The man points toward a dark alley. "Then why look here?" the officer asks. The man replies, "Because the light is better." This "Streetlamp Parable" illustrates observational bias. It describes our tendency to search for answers where data is easiest to find rather than where truth actually resides. To navigate this bias, I