#30DayChartChallenge Retrospective

On the 1st of April, I was twitting about Twitter and noticed some data visualizations in my feed with the hashtag #30DayChartChallenge. Instantly intrigued, I decided to participate without thinking about the bazillion things I already had going on in April. I was excited to expand my portfolio and to explore some datasets I had been collecting for later analysis and visualization.


In retrospect, I wish I had developed a strategy for creating 30 new charts in 30 days that involved a set amount of time I could spend on each viz (say, an hour or 90 minutes) and limitations on data finding, exploration, cleaning, and analysis. I did set two goals other than actually completing all 30 charts (which I did NOT do), though, and managed to accomplish both.

  1. Use a tool other than Tableau for at least one of the charts.
    • I used R/ggplot2/ggridges for one viz, Excel for one viz, and Flourish–a tool that was new to me–for another one.
  2. Make at least one chart type I had never made before.
    • I created several chart types I had never attempted. I felt free to explore and experiment, so I made a waterfall chart, a Voronoi treemap, a Ridgeline plot, and a sunburst chart!

On May 1, I tallied up my chart output and I had 18. Of course I made a chart about my charting.

Check out the interactive viz on Tableau Public.


I didn’t complete all 30 charts, partly because I obsessed over datasets for hours instead of just choosing a nice clean one and getting vizzy. I was thrilled that I remembered enough R to create the ridgeline plot below of the lifespan of various dog breeds by United Kennel Club (UKC) breed group. I used ggplot2, my favorite dataviz package for R, and ggridges, which was new to me.

Data visualization of dog lifespans by UKC breed groups

For Day 12: Distributions – Strips, I made a waterfall chart in Tableau for the first time (with some help from this fantastic tutorial from Ryan Sleeper).

Check out the interactive version on Tableau Public.

For the Tampa’s Palm Trees viz (Day 16: Relationships – Trees) below, I used a new tool (Flourish) to create a new chart type for me, a sunburst chart. Flourish proved very easy to use and has a built-in template for this chart type. (In Tableau, it would have involved a bunch of calculations. At some point I’ll tackle that challenge!) It was also very easy to embed the interactive version of the chart in WordPress.


While the topic of four of my vizzes was dogs (duh), I created three vizzes about COVID-19. (All are viewable on Tableau Public, here, too.)

For Day 7: Distributions – Physical, I looked at Florida’s administration of the COVID-19 vaccine.

For Day 23: Timeseries – Tiles, I explored the variants of the virus circulating in the U.S.

For Day 27: Uncertainties – Educational, I ended up creating this tile map showing the COVID-related school opening orders in effect in some U.S. states. I found a dataset from the State of Maryland with COVID outbreaks in schools, but after spending way too much time cleaning it, I abandoned that idea.

All told, I had a lot of fun and learned some new techniques and tools. I look forward to doing it again next year!

Become #CertifiablyTableau: How to Pass the Tableau Desktop Specialist Exam on Your First Attempt

Since my company invested in a Tableau Desktop license for me (after maybe just a teensy little bit of borderline harassment of the CTO, CEO, and BI Manager), I want to make the absolute best use of the data visualization software, obviously, so it seemed prudent to get some training and prepare for the certification exam. As I researched training and test prep options, I discovered a plethora of resources ranging from no-cost to ridiculously costly. Since I managed to pass the relatively difficult exam on my first try, I want to share what I learned on my training and test prep journey. On Saturday, April 17, at 2 p.m. EST, join me on Clubhouse for a discussion with other Tableau-certified #datafam. We’ll discuss options for how to prepare, what to expect, and how to engage with the super fun, thoughtful, and talented Tableau community. (If you don’t have a Clubhouse account and need an invite, message me!) In the meantime, I have summarized the lessons from my experience below. Let me know if you have questions, comments, or if your experience was different.

April 172021
How to Pass the Tableau Desktop Specialist Exam on Your First TryDiscuss training, exam preparation, and study strategies for passing the Tableau Desktop Specialist exam on your first attempt with me (I did it!) and other Tableau #datafam.
2:00 p.m. ESTClubhouse

Plan to pass on your first try with these tips:

1. Talk to your boss about paying for the exam or reimbursing you.

I did not do this, yet I have placed it at the top of your list. Why? Because I should have done it. I learned so many Tableau–and dataviz in general–tips, tricks, and techniques that will add to my value at work. With so many truly awful, misleading, and ugly data visualizations and infographics in the world, the best practices I’ve started observing have (mostly) reigned in the goofy, weird, or totally random design choices I may have made previously. One of the reasons I invested time, money, and effort into preparing for the exam was that I know what I know (data analysis) and I know what I don’t know (design). Just how much I did not know about design became abundantly clear as I progressed. So ask your boss for the hundred bucks back if you pass. Why not? There’s literally nothing to lose.

2. Download the official Exam Prep Guide.

It’s free and it really does tell you what material is covered on the test. Another no-brainer.

3. Choose a formal training, book, or other prep plan and stick to it.

This sounds straightforward, but like a lot of people, I freeze up or try to do too many things when confronted with too many choices.

Initially, I dabbled. I bought a discounted Udemy prep course and did a few video lessons, watched a few free Tableau training videos, read part of a book, tinkered around somewhat aimlessly in the software, and read blog posts in no particular order until I decided to commit to the DataCamp Tableau Fundamentals Skill Track. Why DataCamp? (No, they are not paying me. YET.) Mostly because I was already subscribed ($29 monthly), already familiar with the platform and organizational style of the courses, and passed my college-level programming course solely through the help of DataCamp’s Python Fundamentals Skill Track.

Once I decided on the DataCamp track, I set aside time to work on it and practice in Tableau every day (e.g., I created a calendar event like I would for any other appointment and did not cancel). Some days I spent fifteen minutes and other days a few hours, but the consistency of daily practice really helped me succeed and remember what I had just learned.

4. Take practice exams and time yourself.

Like I mentioned, I’m aware of my strengths and areas of room for growth. I am a really good test taker. Like really good. And also pretty fast. If I had not forked over a hundred of my own dollars, I probably wouldn’t have taken a single practice exam and I might have failed my first attempt or run out of time. Remember that Udemy course I purchased on a lark? Well, it happened to have three practice exams included. The practice exams helped me assess my progress accurately. I took one before starting the DataCamp track but after a little random reading, video-viewing, and tinkering. I scored about 55%. I took the second one after completing the DataCamp track, reading up on a few topics I knew I had questions about, finishing three Tableau community projects (more on those later), and doing a lot of exploratory data analysis using Tableau. I passed, but with 75%. (I am a reforming overachiever, but that score didn’t leave me feeling as confident as I wanted to be.) I took the final practice exam after scheduling the “real” exam, about five days prior to it. At this point I had worked through the whole Udemy course, which was quite good and didn’t take too long, and felt pretty confident. I scored 90% on the third practice exam. The Udemy course site times you as part of the practice exam, but if you use a resource that is not timed, make sure you set your device accordingly. Generally, I have time left over after exams. On exam day, after moving fairly steadily through all of the questions, I had ten minutes to go back to ones I felt unsure about. It was just enough.

5. “Check yo self before you wreck yo self.” –Ice Cube

This entire preparation process I described above took me about nine weeks, but could take you less time or more, depending on your life. I have a full-time job, a side hustle, three dogs, two book clubs, and ADHD. Consider your own work and school schedule, family commitments, social life, and learning style before assigning yourself a timeline. Be realistic and leave room for adjustment. Don’t schedule the exam until you’re almost ready to take it (although you can reschedule without a fee, if necessary, with advance notice). Scheduling is easy and there were proctors and time slots available as soon as the next day when I scheduled with Loyalist Exam Services, the vendor used by Tableau to administer the exam online.

6. Make sure your computer system and setup are compliant with exam rules (Also, buy a Stadium Pal or a pack of Depends if you can’t go without a bathroom break for 60 continuous minutes.)

The proctoring service requires you to take the exam on a virtual machine in Google Chrome and your internet connection must meet speed and latency requirements (the proctor will check for compliance). I prefer Firefox, so I made sure that I had the latest version of Chrome installed on my computer and did the speed and latency checks a few days before my test. After having some problems with my computer audio, I had a backup plan to test on my Mac instead of my PC in case of mic issues on my appointment date. Headphones are not allowed, so make sure you have a quiet space and your computer has a working microphone that doesn’t require a headset. If you’ve somehow managed to escape the Zoom pandemic, check that your webcam works. The proctor must see and hear you for the entire length of the exam. You can’t get up, so pee first, too.

Finally, join me for Pass the Tableau Desktop Specialist Certification Exam on Clubhouse on April 17! Bring any questions with you! If you’re Tableau certified at any level and would like to join the discussion as a speaker, hit me up!