Planning for Big Data

Chapter 9. Why Visualization Matters

By Julie Steele

A Picture Is Worth 1000 Rows

Let’s say you need to understand thousands or even millions of rows of data, and you have a short time to do it in. The data may come from your team, in which case perhaps you’re already familiar with what it’s measuring and what the results are likely to be. Or it may come from another team, or maybe several teams at once, and be completely unfamiliar. Either way, the reason you’re looking at it is that you have a decision to make, and you want to be informed by the data before making it. Something probably hangs in the balance: a customer, a product, or a profit.

How are you going to make sense of all that information efficiently so you can make a good decision? Data visualization is an important answer to that question.

However, not all visualizations are actually that helpful. You may be all too familiar with lifeless bar graphs, or line graphs made with software defaults and couched in a slideshow presentation or lengthy document. They can be at best confusing, and at worst misleading. But the good ones are an absolute revelation.

The best data visualizations are ones that expose something new about the underlying patterns and relationships contained within the data. Understanding those relationships—and so being able to observe them—is key to good decision-making. The Periodic Table is a classic testament to the potential of visualization to reveal hidden relationships in even small data sets. One ...