The Big Picture: How to Use Data Visualization to Make Better Decisions—Faster

CHAPTER 1

WHY NUMBERS ARE

NOT ENOUGH

People are not very good at looking at a table full of numbers and being able to derive a lot of insight. Let me prove it to you. Consider this simple spreadsheet that shows 12 months of sales data (Figure 1.1).

FIGURE 1.1 Sales by category over time as displayed using a spreadsheet.

Which category has the largest sales, and which has the smallest?

Easy! Just put the totals in a column on the right (Figure 1.2).

FIGURE 1.2 Sales by category over time, with totals.

But suppose we want to know in which months ...