Data visualization and visual communication by Robert Kosara
I've always been fascinated by photos with long exposure times. Your typical snapshot or phone pic essentially captures an instant in time. But extend the exposure, and water turns to glass, cars turn into light streaks, and people disappear. An extreme version of this is the solargraph, which shows the path the sun takes over weeks or months. Solargraphs are really weird and interesting, and the…
Well look at that, a new blog post! This site has been dormant for a while, but now it's ready to come back. The short version is that I've created a new static site for it that's more modern and hopefully easier to navigate. It also makes it a lot easier to build new sections and add interactive pages and little apps. I'm working on bringing back some of my old interactive pieces (which I'm now…
The words business and data visualization probably put you to sleep before you even reach the end of this sentence. But wake up! There's actually a lot of interesting work to be done in this area, if only we give it a chance. I think research has ignored this space for too long, and is missing out not only on more ways to create better applications, but to find really interesting research problems…
Before we had D3 and all this fancy web technology, interactive news pieces on the web were usually built using Adobe Flash. Some of my favorite news graphics are from that era, and when I talk about them I like to joke that they're so old they were done in Flash (a joke that dates me as much as it dates these news graphics)! The problem is that Flash, while ubiquitous in the early 2000s, was…
Rainbow colormaps are among the most derided ideas in data visualization, second only to pie charts. And yet, people use them. Why? A recent paper looks at some of the reasons why they are so popular and points to research showing that they might not be so bad if used for the right tasks. There's even opportunity for interesting research in rainbow colormaps! Finger-wagging about rainbow colormaps…
Computational notebooks offer an alternative to the common GUI-based tools used for data visualization and BI today. In this new paper, I talk about what they are, their pros and cons, and how research could fill in some important gaps. Data visualization research has focused primarily on graphical user interfaces (GUIs) for creating data visualization, and for good reason. But notebooks have been…
I'm teaching a short course on data visualization for Observable . It's free, and you should join! Starts March 7. The course will cover the fundamentals of data visualization, like the key chart types, how they work, when and how to use them. We'll also talk about transformations of data, like binning and smoothing data, and of course interaction. We'll use Observable's Plot library for the most…
Josh On's They Rule is back, and I've made a video about it. They Rule connects companies through their boards of directors. You can follow these connections between seemingly unrelated companies, and sometimes even competitors. By web standards, They Rule is quite ancient. It has been around since 2001, and since it was initially done in Flash, it was effectively offline for the last few years.…
This site has been around for over 16 years now, and a lot has changed in the world during that time. I'm currently working on an overhaul and wanted to give everybody an idea of what I'm thinking about and why there has been little activity. In light of recent developments, here are also some good ways to follow good old-fashioned blogs and an alternative to Twitter. Site Changes When I first…
Of the several AI-powered systems that can create images from text prompts, MidJourney is the most easily accessible one right now. I've had some fun playing with it. Midjourney produces images from prompts , which are basically text descriptions. They don't have to be specific or concrete in any way. "Astronaut riding a horse in space" works just as well as abstract words. In fact, the latter can…
Gauges aren't very popular in visualization, but they have some interesting properties. There is, of course, the infamous NY Times "election needle," but you're probably using gauges every day without giving them too much thought. There's also an interesting connection with circular bar charts, which I think can work well when used as part-to-whole charts. I talk about all of this in my new video.…
I gave a talk at the Outlier conference earlier this year, with the somewhat elaborate title, The Joys – and Dangers – of Bespoke and Unusual Chart Types . Though I eventually decided to go with the much shorter, This Should Have Been A Bar Chart! You can watch it on YouTube now. In the talk, I go through a number of examples, some of them recent, some of them a little older, of charts that are…
Encodings play a central role in visualization, but I believe our thinking about them is too simplistic. In a new paper, I argue that we need to distinguish between the encodings that specify how a visualization is drawn and the ones that are readable or actually read by an observer. While they largely or entirely overlap in some charts (like bar charts or scatterplots) they don't in others (pie…
A bar chart with a distorted vertical axis isn't very unusual. But what if that chart was posted by the White House and what if it was done on purpose – not to overstate the number shown, but rather to evoke a particular kind of response? The Chart Last week, the Biden White House published this chart showing that U.S. GDP had grown by 5.7% in 2021. That's the most in many years, with the chart…
An opinion piece in the New York Times last week got a lot of attention in visualization circles for its use of a spiral chart as its opener. While the choice of chart and color scheme can be debated, I want to discuss the fact that the spiral is disconcertingly off-center. The piece in question is titled Here’s When We Expect Omicron to Peak . The opener image, which attracted a lot of attention…
The common explanation for how pie charts work is that we read them by angle. That of course would mean that donut charts would be bad, because you can't see the angle when you take away the center of the pie. Changing the radius of a slice wouldn't matter though, because that doesn't change the angle. But there is no evidence that angle is how we read pie charts, quite the opposite actually. In…
Who are the people who use data and visualization as part of their work every day? In particular, how do people use data as part of meetings, to present to others, to discuss their findings and recommendations, etc.? My colleague Matt Brehmer and I ran a pair of studies to find out. I’ve written a little blog post about the paper over on the Tableau Engineering Blog (no longer available), and I…
EagerEyes is 15 years old today! Rather than look back at 15 years of visualization and blogging (though I will do a little of that too), I want to reflect a bit on what blogging means today and where things are going. Blogging Is Over It would be easy to think that blogs are old-school and nobody pays attention to them anymore. I don't think that's true, but they certainly have a lot more…
Can you put ranked data into a pie chart that also represents time? This chart tries, and I think it succeeds. This chart was posted by Cal Fire a few days ago on Twitter. It shows the acres burned by the 20 largest wildfires in California. Yes, it's a pie chart. We're looking at ranked data here, even though the chart isn't sorted by size of the fire. It's sorted by time, when the fire started.…
How do you make people not just see numbers when looking at a chart, but feel something? This chart of the number of deaths during the Iraq war has always given me a visceral response like no other, and it’s still as powerful as when it was made almost ten years ago. So I made a chart appreciation video to explain what I think is so great about it. I’ve written about this chart and other…