Monday, November 18, 2013

slopegraph template

I've found myself increasingly using slopegraphs as of late. They can be useful when you have two time periods of data and want to quickly see increases/decreases between the two periods (example below; see second half of this post for more discussion and another example).
From a formatting standpoint, however, they are annoying. They take a lot of time to set up because basically everything is different from graphing application defaults. I realized as I was making a recent one that I make the exact same changes every single time and may actually leverage a template for this (I say "may actually" because I thought that would be the case once before, but it didn't happen, though I've heard from others that they do use it).

In case you find yourself wanting to use a slopegraph (or quickly see whether one will work given the specifics of your data), you can download the Excel template I created here (screenshot below).

Tuesday, November 12, 2013

what I look for in effective data viz

Last week, I had the distinct honor of being one of the judges for the very first VizCup, hosted by Facebook. Participants had an hour and their choice of half a dozen or so datasets plus their preferred software to create an interactive data viz. Each group/individual then had 90 seconds to explain and demo their visualization. After an hour or so of seeing some amazing work, the judges narrowed it down to the top five, who each had a little more time to share their viz. Top entries ran the gamut in scope, ranging from being able to see UFO sighting stats on your birthday, to where to locate to avoid natural disasters, to the winning entry that looked at the bias in soccer red card handouts by referee. Interestingly, all of the top entries (and nearly all of the entries overall) were created in Tableau, likely due to its ease and speed in creating interactive visualizations.

Leading up to the event, I put some thinking time to the most important things that I look for when judging the effectiveness of a data visualization. I thought this might be of interest, so will share it here.

At a high level, there are four things I look for when evaluating data viz:
  1. A sensible display. The choice of graph or visual is appropriate given the data and given the purpose.
  2. Absence of clutter. I disdain it! The presence of elements that don't carry informative value or aid interpretation in some way will hurt not help when it comes to my evaluation.
  3. Affordance in design. Through strategic use of things like color, size of elements, spacial position, and text, it is so clear to the audience how to interact with the data visualization that they don't even notice the design.
  4. A clear story. For me, the best data visualizations are the pivotal point in a story. Use written or spoken narrative (or a combination thereof) to make the story your visualization tells clear.
Big thanks to everyone who worked to make this event a success: the Facebook team, the other judges (Drew Skau from and Anya A'Hearn of DataBlick), and especially Andy at VizWiz for inviting me to take part in the event!

The Facebook team that organized the event, plus judges.

Thursday, November 7, 2013

student makeovers

This fall, I had the pleasure of teaching Intro to Information Visualization for MICA's MPS in Information Visualization. It was a 4-week course, where we explored some fundamentals of data visualization and storytelling as it relates to communicating effectively with data.

The course was unique from my typical workshops in a number of ways. It was great to get to start to know the students during our time together. Perhaps the most exciting difference for me was being able to see the lessons we covered put to use in homework assignments.

One of the assignments was a visual makeover, where students were asked to select a less-than-stellar visualization from the media, identify the underlying story and create a new and improved visual using data together with narrative to tell an effective visual story. I had a great time reviewing the before-and-afters. I thought I'd share this fun with you by posting some of them here (with my students' permission; I realize the snippets below are a little small - and my process for getting images onto my blog has started to create a sort of strange grey background, so if you want to see bigger non-grey-background versions, you can download the PDF here). Enjoy!

Makeover 1: bird feeder location  by Kevin Ripka |

Makeover 2: youth programs  by Brittney Younger

Makeover 3: NYC refuse  by Marianne Siblini

Makeover 4: BB Finale  by John Breakey |

Makeover 5: climate change  by Jennifer A. Stark

Makeover 6: prezi growth  by Jess Mireau |

Big thanks to the students above for agreeing to let me post their work, and to the overall class for making my first time teaching at the graduate level an incredibly rewarding experience!