NPR's David Eads writes that locating a database that's relevant to your story is just the first step. Next, you have to examine the data in detail, look at the values, and ask some basic questions: "Good questions to ask when researching data: Who created it? Who is responsible for maintaining it? What point in time or time-range does it apply to? How was the data collected? How was the data processed after being collected? How was each field collected or calculated?"
December 28, 2015