What is Data Visualization?

Adam Janes
A free video tutorial from Adam Janes
Data Visualization Engineer
4.4 instructor rating • 2 courses • 14,397 students

Learn more from the full course

Mastering data visualization in D3.js

Design and build beautiful data visualizations with d3.js. An intensive introduction to the D3 library (V6).

06:51:47 of on-demand video • Updated June 2018

  • Understand the fundamental building blocks of D3
  • Gain a wide breadth of knowledge, learning how to create 14 different visualizations
  • Critique existing visualizations and invent better designs for displaying data
  • Interpret open source code from the D3 community for use in your own projects
  • Master advanced tools in D3, building choropleth maps, brushes, tooltips, and layouts
  • Develop substantial web apps, with multiple visualizations on the page at once
  • Articulate original abstract ideas with compelling sketches
English In this lecture, I'm going to be giving a quick introduction to data visualization. I'll be showing you how we can split up visualizations into three distinct types, and I'll be showing you a few examples of each. So what exactly is a visualization? A quick search on Google gives us these two definitions. For this class, we'll be interested in the first definition, which involves representing some kind of abstract information in a visual form. If you're looking for a class on visualization that covers the second definition here, then this might not be the right course for you. Data visualization is a pretty broad discipline which can cover all sorts of different things. For the purposes of this course, we can split up the most common uses of visualization between exploring data - helping us discover something new; analyzing data - testing a theory about the state of the world; or presenting data - which involves communicating something to others. For exploring data, visualizations can be used to find some kind of unknown. A classic example here is the work of Edward Muybridge, who was tasked with settling a bet by finding out whether galloping horses ever have all four hooves off the ground at once. This isn't something that we can tell by the naked eye, so Muybridge used a series of experiments with photographs to find this out for sure. The result from these pictures proved the matter once and for all, as you can see here in the top few frames that the horse is completely in mid-air for a good part of its stride. For a more practical example, for your final project in this course, you'll be building a data dashboard that lets a manager compare the sales performance of different teams in his workforce. Here, the goal is to provide a visual tool to determine how these groups compare side by side, exploring the raw numbers to see how this has changed over time. The manager can then determine which groups are causing the most problems in his business and act accordingly. For analyzing data, visualizations are made to test the hypothesis that we have about the state of the world. A classic example here is from the 19th century Docor John Snow. Not this one. He used a heat map of cholera cases in an area of London to prove his hypothesis that these deaths were spread by water pumps in the area, rather than by decaying organic matter, as other people had thought. For visualizations focused on presenting data, the goal is to communicate some kind of story, and hopefully to inspire people to take action. The most common examples here are from the New York Times, who often run interactive data visualizations on their website. These visualizations appear within a block of text that communicates a certain story, and the visualizations are built to support it. Now that you've learned a little bit about what visualizations look like, I want you to look for the best visualization that you can find online. Some great places to start are on Reddit at the subreddit "data is beautiful", flowingdata.com, which has a lot of visualizations built with D3, or you can just start looking for visualizations on Google. A great thing about Udemy is that you can take this class alongside many other students who are going through the same learning process as you. I want you to share your favorite visualizations in the comments to the next activity, so that we can crowd-fund some of the best visualizations out there. See what your other classmates have come up with and really get a feel for how varied displays of data can be.