Book Review: How Charts Lie by Alberto Cairo

I recently had the pleasure of reading Alberto Cairo’s latest book How Charts Lie.  No matter if you are a data visualization expert or only familiar with charts you see on TV and in the media, this book will help you make smarter decisions in reading and interpreting the charts you encounter in your daily life.  I highly recommend reading it.

How Charts Lie provides a captivating mixture of topics touching on philosophy, sociology, and graphical literacy (also known as graphicacy).  Cairo does a masterful job of providing guidelines and guideposts on how to read and analyze not only charts you see but any data that you are presented.  Where this book set itself apart from others in the data visualization genre is the examination of how these charts and data interact with the reader’s mind.  By providing many real-world examples of chart trickery (accidental and otherwise) readers will become more discernible consumers of information.  Additionally, as important as being a responsible information consumer, Cairo delves into the responsibility incumbent upon chart creators and even those that simply pass along charts to others.

One poignant message that Cairo delivers throughout the book is that a chart only shows what it shows.  Beware of inferring causation from a chart because of personal beliefs or the chart creator’s bias.  Make sure to take the time needed to analyze what is being displayed.  If a visualization appears too good to be true, it’s at least worth researching further before solidifying an opinion.

This book has provided me greater cause for thinking about charts that I see and to have conversations around data and news with an open mind.  To be open to persuasion while being mindful of trickery and my own implicit bias.  The book goes on sale on October 15th.  Make sure to add it to your reading list and pre-order it from Amazon here:

TC19 Resolutions: How To Stay Accountable To Your Data Viz Goals

For many, the end of the year is a time for reflection.  Even though the actual day of January 1st isn’t much different from December 31st or February 8th or June 16th, it marks the beginning of the new year, and with that comes a host of expectations, promises, and resolutions.  

At the end of the year, we take stock of the previous 12 months.  We relive our accomplishments, think about what we left unaccomplished.  We ponder what we’ve lost or what might have been.  And for so many, in the US and around the world, we create a list of resolutions for the coming year. These resolutions are milestones that we set for ourselves, usually with the goal of improving our lives or the lives of others.

Resolutions often focus on improving physical health, quitting bad habits, becoming more charitable, or learning new skills.  And while most resolutions are created right before the new year, there are other annual events that may also bring resolutions to mind.

For the data viz community, and specifically the Tableau community, the Tableau Conference holds much of the same wonder and excitement as New Year’s Eve.  It comes once a year. It’s celebrated by thousands of others in our community (our data community in this case). It brings a whole host of expectations, new experiences, learning opportunities, and lots and lots of personal reflection.  

#TC19 Resolutions

After this year’s conference in New Orleans, I saw this tweet from Vince Baumel inspiring the community to share some resolutions for the year before 2019’s Tableau Conference.

Vince Baumel tweet

The end of TC18, along with Vince’s tweet, got me thinking about my personal Tableau and data viz growth over 2018.  All in all, 2018 was a great Tableau year for me. I attended my second Tableau Conference. I passed the Certified Professional exam.  At the time of the conference, I’d posted 38 vizzes on Tableau Public for the year.

Now was the chance to create my #TC19 resolutions, or more specifically, the resolutions that would continue to grow my personal Tableau and data viz skillset and grow my online persona, while also making sure that I was giving back to the wonderful community.  With those goals in mind, here was my original #TC19Resolutions tweet:

To make sure they were all clear and quantifiable, I revised them into the following list:

  1. Write 5 blog posts
  2. Attend at least 6 TUG meetings
  3. Create 3 original vizzes where I source or create the data
  4. Reach Level 15 on the Tableau Forums

Blog Posts

I had wanted to write a blog for over a year.  I’d even registered this domain right after TC17 ( but never actually wrote a personal (non-work related) blog post.  I had a few ideas of what I wanted to write. However I had been prioritizing creating new vizzes and participating in data viz challenges over sharing my written knowledge with the community.

There are so many wonderful blogs out there that it was easy to feel like I may not have much to contribute.  However, every time I’ve shared my knowledge and experience with the Tableau community (whether talking to people in person, sharing my knowledge at work, presenting at the Tableau Fringe Festival), the feedback has always been positive.  After TC18 I was determined to start writing, and more importantly publishing and sharing, original written content with the community.  5 blog posts sounded like a good start.  Though I’m hopeful that the initial 5 will lead to many more.

TUG Meetings

Tableau User Group (TUGs) exist all over the world and hold meetups on a semi-regular basis (both in-person and virtual).  TUGs offer the incredible experience of meeting and networking with other Tableau and data viz minded individuals, as a space for learning and sharing knowledge with others, and a great place to learn about the latest Tableau news or upcoming announcements.  

While I hate to admit this, before this year’s Tableau Conference, I’d only ever attended one Tableau User Group (TUG) meetup.  I knew that I was missing out on a great opportunity to interact with the community by not attending more. Therefore I am making it a point to attend at least 6 meetings before the next Tableau Conference.

Original Vizzes

If you’ve followed me on Twitter or seen my Tableau Public profile, you’ll know that I love to participate in data viz challenges.  If you’d like to learn more about these challenges, I encourage you to read my previous blog post: Are You Up To The Challenge?

I credit much of my personal data visualization growth, especially over the last year and a half, to the number and breadth of challenges that I’ve participated in.  Each one has provided me with an experience for improvement that I would not have had otherwise.

As most of the challenges focus on viz creation, they tend to provide a nice clean dataset at the start.  However, for anyone that works with data visualization in a professional environment, you’ll know that you are almost never handed clean and organized data.  More often than not the data is in disparate sources and formats. You may not even know where all of it is at first. This data generally requires cleaning and manipulation before you can even start to create a viz.

So, as a way of continuing to step outside my data viz comfort zone, and wholly inspired by the wonderful original work put out by the community, I resolve to create at least three original data visualizations in which I’ve either sourced the data myself or created it directly.

Tableau Forums

The forums are the most underrated and under-appreciated feature of the Tableau community.  Almost every time you search for a Tableau answer online, you are directed to a link on the forums.  If you use Tableau regularly, you will inevitably find yourself at some point researching an answer on the forums.  

Not only can you research a question there, but you can post an original question as well.  There are a host of other Tableau users in the community who regularly monitor the forums and are committed to helping others answer their questions.

Prior to TC18, I had really taken the forums for granted.  I’d searched for answers on it many times, but never posted myself, nor had I taken the time to help others answer their questions.  I’ve often been the Tableau and data viz resource for others at work, and am always happy to help with whatever questions my co-workers have.  I only made a minimal effort to expand my help beyond my office though.

I wanted to change that going forward.  To set a quantifiable goal for participating in the Tableau forums, I decided to use the point system that the forums have in place.  They have a point system (a somewhat addicting point system) that allows you to level up as you help others on the site. The highest level you can currently achieve is Level 15 – Data Monarch, which requires 7,900 points.  

My original goal was to reach Level 7 – Data Rockstar, but after I started participating in the forums and helping answer others questions, I quickly realized how much I enjoyed it.  It is very gratifying to help others in the community.  Not only that, but I have been learning a lot from my time on the forums as well.  I’m more engaged with answers posted by others.  I’ve also had the opportunity to answer questions that have really had me stretch my Tableau knowledge and have caused me to learn more in the process.

Level 7 requires 1,100 points but I quickly blew past that.  My current goal is to reach Level 15. Along the way, I’ll be helping many others with their Tableau questions and will continue learning myself as well.

PUBLIC SERVICE ANNOUNCEMENT: If you have not done so yet, start participating in the forums, even just a little bit.  It will greatly improve your skills, while you give back to the community, and it’s free.  You can’t beat all of that.


What really struck me about Vince’s #TC19Resolutions tweet was the accountability piece.  So many times we create and maybe even share resolutions, only for them to be forgotten by the end of the coming year.  How could I improve my ability to keep myself accountable? The best answer I could think of, especially for data viz related resolutions, was to create a viz about it.

Here’s my #TC19 Resolutions tracker:!/vizhome/TC19ResolutionTracking/TC19ResolutionTracker

#TC19 Resolution Tracker

Between writing this blog post and creating this resolution tracker, I plan to keep myself publicly accountable to my resolutions.

For any of you that posted your own TC19 Resolutions, or would like to do so now, I encourage you to share them with the community as a means of keeping yourself accountable.  Go ahead and tag me too. I’d love to see your resolutions for the coming year, and am more than happy to be your accountability partner for fulfilling your own resolutions!

Happy Holidays and Happy New Year to all of you!  Wishing you all the best in 2019. Never stop learning, never stop reaching, never stop giving back.  I hope that you accomplish everything you set out to do this coming year.

Are You Up To The Challenge? My Creative Process for Data Viz Challenges

Have you heard of #MakeoverMonday or #WorkoutWednesday?  I’m sure many of you have, but if not, they are two of the many free and publicly available challenges offered by the Data Visualization community.

Some challenges are offered weekly while others are monthly.  Some focus on creation of new visualizations while others focus on challenging you to recreate existing ones – with the goal of teaching new visualization techniques.

For me, there are three main reasons why I have become a regular participant in these challenges over the last year and a half:

1. Practice

As with any art form, to get better at data visualization you need to practice. The more that you create, the more scenarios that you encounter, the more functionality that you’ll be able to understand and use, and the better your skills will become.  You can never stop learning or get enough practice with data visualization.  Even Tableau Zen Masters are constantly learning and working to expand their knowledge.

2. Accountability

While it’s easy for me to set goals for myself, if I don’t have a means of staying accountable to those goals, I have a much harder time of staying on track. Creating these challenge visualizations, publishing them to Tableau Public, and then posting them on social media has been a great way for me to stay accountable to my progress.

3. Building a Portfolio

Along with accountability, as I continue to publish my work on Tableau Public, I’ve amassed a nice portfolio of non-job related data visualizations. This has been especially useful when I’ve applied for new positions in the past.  You usually cannot show potential employers visualizations you have done at work, but if you have worked on things on your own time, and have them published on Tableau Public, you have a portfolio of your work in reverse chronological order.

My Creative Process

I just recently participated in #ProjectHealthViz, a monthly challenge by Lindsay Betzendahl focused on publicly available health data.  Health data is fun to visualize as there are many different stories to be found within the data and many different ways of presenting them.

This month’s dataset was from the CDC and focused on disease outbreaks across the US.  The data was in an excel file with over 400 thousand rows.  Each row contained information on a single outbreak.

Let’s walk through how I got from the raw data to my final viz.


Norovirus Outbreaks!/vizhome/ProjectHealthVizNovemberNorovirus/NorovirusOutbreaks

Process, Not Rules

While each challenge is different, when I’m creating something new there is a general process I follow.  By no means are any of the following points meant to be seen as rules (very few of those exist in data visualization).  Rather my intent in sharing these guidelines is to provide a spark to those who are just getting started with these data viz challenges and provide a possible structure for doing so.

Reviewing Data Structure

The first thing I do when presented with a new dataset is to look at which data fields are available.  In this data from the CDC, there were:

  • date fields for when an outbreak occurred
  • state location information
  • an Etiology field that listed the name of the disease
  • some descriptor fields (like mode of transmission and outbreak setting)
  • several measures including the number of illnesses, hospitalizations, and deaths.

When reviewing the structure of the data, you want to get a general understanding of what your main dimensions and measures will be for your visualization.

Exploration and Choosing a Topic

This CDC dataset is a little on the heavier side as far as content goes but it’s rich with stories to be told.  To decide which story I wanted to tell, I needed to explore the data.  While I could have done this in Excel, I like to bring the data into Tableau to start exploring.  I start by reviewing overall statistics with the goal of finding a topic that stands out in the data.

For this dataset, that included the following:

Number of Outbreaks Per Year

Outbreaks per Year


Total Outbreaks by Location

Outbreaks by Location


Outbreaks by Location 2


Number of Outbreaks by Disease Type

Outbreaks by Type

It was clear from my exploration that Norovirus had the most outbreaks of all the diseases in the dataset.  I decided at this point to use Norovirus as the focus for my viz.  While I don’t always create visualizations based on the highest or lowest numbers in a dataset, once I have found a good topic I like to start creating my viz in Tableau.

Although you can and should take as long as you’d like when creating your own visualizations, I try to keep some structure around the amount of time I spend on any single viz.  Some take longer than others, but I have a family and friends that I like to spend time with so I make sure my viz time does not take away too much from my personal time.

Telling a Story

Sometimes you have a dataset and you know exactly the story you want to tell right away.  In those cases, you may start by creating the overall design of your dashboard and filling it in with your data later.

I tend to start with the data before I create a dashboard.  I create several different charts, and iterations on those charts, before I put them all together.  For the #ProjectHealthViz challenge, I created several different views.  However, not all of them made the final version of my dashboard.

It’s up to you how many charts you want to create before combining them into a dashboard, but don’t feel like everything you create needs to be included.  Sometimes your best ideas don’t come till after several iterations or a few times stepping away from your computer and coming back to it.  More importantly, even if you really like one of the several charts that you have created, if it doesn’t fit with your overall story, you do not need to include it in your final viz.

Putting It All Together

Once I have a few different views to choose from, I start putting them together.  My dashboards usually are not the same shape or size, and I often resize my dashboards as I’m working on them.

The one actual rule I stick to though is using fixed dashboards.  You never know what size screen your viewers will have and if you do not fix the size of your dashboard, it may stretch or shrink in ways that make it unreadable.

Alignment and Chart Selection

There are many different ways to layout your dashboard.  I often like to make a rough sketch with a pencil and paper of what I want my dashboard to look like.  This helps me visualize what I want to do before I start creating in Tableau.

For my ProjectHealthViz I decided that I wanted to make it look like a long and narrow infographic – something where the story builds as you go from top to bottom.  While I had several charts to choose from, I decided on these three to present the data:

  • Bar Chart
  • Hex Map
  • BANs (Big Ass Numbers)

I’ve used bar charts and BANs many times in the past.  They’re both great ways to highlight simple information.  The bar chart I created clearly shows that Norovirus is the top cause of outbreaks in the US.  The BANs at the bottom deliver raw numbers for how many have been affected by Norovirus.

As for the hex map, while I could have used a traditional map instead, there are two reasons I chose the hexagon style.

  1. It makes it easier to see the number of outbreaks per state when each state is the same size.
  2. I’ve always wanted to create a hexagon map and hadn’t done so before.

While some charts are more effective than others for different scenarios, sometimes stretching your ability by trying something new is fun too.  And data viz should be fun!

Font and Color

I’m no expert on fonts.  However, Tableau Public has a limited number of fonts it can render.  Since the options are limited, it’s not too difficult to choose a font.

Jennifer VonHagel put together this great resource on which fonts are supported by Tableau Public and how they look:

I personally like the look of the Georgia font but sometimes stick with Tableau Regular (and use Tableau Bold or Tableau Semibold for bold characters).  For my ProjectHealthViz, I stuck with Tableau Regular and Tableau Semibold.  The bold function does not work well with Tableau Regular so I used Tableau Semibold for making certain text and numbers stand out.

When it comes to color selection, I try not to be too flashy.  You don’t want extra color taking away from what you are presenting with your data.  You also don’t want to use color that doesn’t have meaning.  Color can be a great asset in your viz, but it is also very easy to overuse.  My recommendation is that less color (and a fewer number of overall colors) tends to work better for visualizing data. In my viz, I used red to highlight the outbreaks while keeping everything else black or white.

Custom Fonts in Tableau

For my title at the top, to give it a little something more than the standard font look, I turned to PowerPoint.  You can create a title in PowerPoint using any font available, save it as an image, and import it into your viz as an image.  This way it looks like you’re using custom fonts, even though they’re actually image files.

At the end of last year, Zen Master Ken Flerlage tweeted about a tool called that lets you type in a word or phrase and see how it looks in all of the fonts installed on your machine.

I’ve used on several of my visualizations. It’s an easy way to find a font for a custom title, especially if you do not want to go through each font in PowerPoint one at a time.


The footer is where I place information to tag my viz as my own.  I put the name of the challenge I’m participating in and my Twitter handle.

This is also where two very important pieces of information should go:

  1. Link To Your Datasource:  If the data is publicly available, make sure to cite where it came from.
  2. Attribution: If you were inspired by someone else, or took a similar approach to a visualization as someone else, make sure to note that in the footer. Attribution in data visualization is as important as attribution in a book or research paper.

Be Deliberate About Difference

Once your viz is done, make sure to review it.  Check for consistency in both your font usage and your colors.  If you decide to make something a different font or color or shape than other items in your viz, do it intentionally and know that you did it. Do not do it because you overlooked it.  Be deliberate about difference in your viz.

Check your tooltips too!  They’re often overlooked and can be a useful feature for including additional information.

Pro tip: It never hurts to have someone else review your viz.  The Data Viz community can be a great resource for this, but sometimes it helps to have someone from outside the field review it as well.  If they have trouble interpreting your viz or understanding your data, you may need to make it clearer.

Get Started!

Sometimes getting started can be the hardest part.  Regardless of the process you use, the most important part of getting started with these challenges is to create something.  Import your data into Tableau and start making charts.

I’d say the second most important part is sharing your finished viz online.  For me, sharing my work online has been the best way to stay accountable to my progress and to elicit feedback from the community.

Here’s a list of challenges that I have had the pleasure of participating in (in no particular order):

 I challenge you all to participate in more challenges.  And if you ever would like any feedback on your visualizations, I’m more than happy to help!