Businesses are using more data than ever to inform decision making. While the truly large Big Data may be limited to the likes of Google, Amazon, and Facebook, publishers are nonetheless managing more data than ever before. While the technical challenges may be less daunting with smaller data sets, there remain challenges in interpreting data and in using it to make informed decisions. Perhaps the most daunting challenge is in understanding the limitations of the dataset: What is being measured and, just as importantly, what is not being measured? What inferences and conclusions can be drawn and what is mere conjecture? Where are the bricks and mortar solid and where does the foundation give way beneath our feet?