What is the best way for journalists to learn D3.js?

Can you outline your experience and the path to success for people who have never thought about getting into coding? Is training journalists different to other groups?

I love working with journalists because they are uniformly curious and energetic people. To me, curiosity and energy are the only two things you really need to get into creative coding and data visualisation. You need a computer, of course, but that’s really secondary. I have taught many classes and workshops with non-journalists -- people in other industries -- and it’s so sad to me when people take the class simply because their boss told them to, or because they think it would be a good step for their career. When their heart isn’t in it, learning to code is a struggle. The learning process should be both fun and challenging at the same time.

Many people will ask -- how long does it take to become productive with data visualisations in general?

New practitioners can become productive right away, starting with their first sketches! There is no need to be an expert or have years of experience; everyone has to start somewhere. Just start sketching and -- crucially! -- sharing your creations.

The field is exploding in size and reach right now; the more you can share your ideas, the more you get to be a part of this growing conversation.

What are the most important concepts for understanding D3?

D3’s principal concept is data binding, in which data values are attached to (or ‘bound’) to elements of the web page. Those elements are usually visual things, like rectangles in a bar chart, or circles in a scatterplot. But they can be anything, such as shapes representing different countries on a map. Data binding is so powerful, because then going forward, each element continues to keep track of its own data.

For example, say you make a world map, and your data has values for each country like total population, GDP, and land area. Once the data values for each country are ‘bound’ to the shape that will be used to represent each country, it is easy to adjust visual properties. You just tell the shapes what to do, such as ‘colour yourselves in according to population values’ or ‘make yourself red if your GDP exceeds x amount; otherwise, make yourself grey’.

You are teaching D3.js and you are a contributor to Processing. How do they differ? Which is the better one to start with?

Processing is a language and an application designed for a beginner audience. D3 was never intended for beginners; it is trying to address a different need -- loading data and displaying it on the web. And, the web context is enormously more complex, involving interactions between different technologies like HTML, CSS, JavaScript, SVG, and so on. That said, I always recommend people start learning what seems most relevant to them.

You describe yourself as a ‘code artist’. What is your personal motivation and background? How did you get into coding and interactive data visualisation?

Looking back (way back!), my first coding class was in LOGO (I think we used Commodore 64s, as this was even before the Apple II came out!). LOGO, for those who haven’t heard of it, is a language created in the 1960s by Seymour Papert. It is a language designed specifically for children -- Papert wanted to create ‘building blocks for the mind’, and saw computing as a powerful tool for helping children explore abstract ideas like logic, mathematics, and geometry (I recommend Papert’s book, Mindstorms, for more). In LOGO, by typing in commands like ‘FORWARD 100’ you can make an on-screen triangle (the ‘turtle’) move around, drawing lines to the screen as it goes.

Processing is a modern, conceptual descendent of LOGO. It has a similar pedagogical intent -- a language designed for learning language. It is a beautiful project and allows me to relive that same feeling of excitement from my first taste of LOGO.