What is data visualization

What is data visualization? Let's start off with the poor lowly bar chart, one of the most basic and common forms. It's arguably the best form of data visualization. If you have one variable to communicate and the emphasis is on the magnitude of the values across different categories, and the goal is probably to allow comparison, you really can't do much better. In this example, we're looking at a sales performance chart and you could easily see that 2006 was the best year, 2008 was the worst year, 2009 didn't do much better either, and then the other years are sort of in between those extremes. It's easy to see the headline and the overall story here. In different chart forms, it might be hard to see the variations, for instance, between 2008 and 2009. The bar chart's great, it works fantastically. It is important to note that, whenever you're doing visualization, you should always ask yourself, why should I not do a bar chart? That should be the first thing you think of.