An Iron Viz Finalist: A Retrospective

This was originally posted on my first blog, Data vs Food, in July 2018

Being on the Iron Viz Stage at TC18 Europe is an experience I’m never going to forget!



Thanks to everyone who came along and watched what Sarah, Klaus, and myself could do in 20 minutes, I don’t think that any of us disappointed in what we did! After much deliberation from the judges Klaus was a worthy winner with a fantastic, eye catching viz. Being on that stage could get addictive, so I’ll definitely be entering Iron Viz again!

In case you missed it, there’s a highlight video (check out our strutting!)

But taking it back a step back, why did I enter Iron Viz in the first place?

I find starting with a completely blank canvas a difficult thing to do, with Iron Viz you’re only given a very slight push with the theme of the competition. Trying to do something you don’t necessarily want to do can be a really good way to learn.

Iron Viz gives you a huge amount of freedom to do whatever you want in whatever you way you want to. As long as you keep in mind the three categories you’ll be scored on – Analysis, Design, and Storytelling.

When I entered I didn’t set out to get through to final, I just wanted to make something people may find interesting.

But most importantly I wanted to make something I was really proud of.


My Viz from the Final

If I’m reading something where there’s a finished product at the end, it’s always nice to see that near the top without having to scroll or read to the end, so here it is. This is what I made in 20 minutes. The actual vizzes from the day are currently sitting on the laptops we left on stage, so the one below is a practice version (but virtually identical).

Click the image for the interactive version

I’ve got to admit, I wasn’t a huge fan of the dataset we were given. It took me ages to get my head round what the Big Mac Index actually was and what insight it provided, I’m still not entirely sure I completely understand it!

This year the Iron Viz process was a little different. Tableau Prep had been released around the time the three of us got through to the final, so we were given the option to use Tableau Prep to connect additional data sets to the Big Mac Index. To account for this additional time required looking for other data sets, we were given the main dataset about a month before Iron Viz.

I spent a good two and half weeks throwing extra data at the Big Mac Index to see what stuck. One story that I really tried hard to make work was connecting the price of a big mac to obesity statistics. I found data around body mass index per country and NHS admission stats where the primary or secondary reason for admission is obesity. I thought this would be an apt story to tell as the final was held on the 70th birthday of the NHS. But I couldn’t work out a suitable story and the data was of questionable quality so I went back to the drawing board. At this point I was trying all sorts of things: Does it vary by continent? Is it linked to the average salary in each country? Is there a story around the nutritional value? (this varies a surprising amount by country).

At this point I was feeling a little desperate so I decided to start removing data instead, that’s when I noticed Venezuela.

The Story – What is the data saying?

I’m not qualified or learned enough to fully explain what’s going on in Venezuela, this Wikipedia article might help give a bit of background. It’s also worth reading some of the news stories, though they are heartbreaking.

The overall story I was trying to tell was how something as innocuous as the price of a Big Mac, can be an indicator of serious problems within a country.

The economy of Venezuela is connected so heavily to the price of oil, when it fell from $100 per barrel to only $38 this affected the entire country and led to hyperinflation. Over the course of 2 years the price of a Big Mac in Venezuela went from 132 bolivars in July 2015 to 10,950 bolivars in July 2017. The final part of my story was from the university research that had found nearly 90% of Venezuelans are living in poverty.

The Design – Making it flow and getting your attention


To try and tell my story in as clear a way as possible I went with a very simple layout, just 3 sections.

I borrowed this general layout from previous Iron Viz winner Tristan Guillevin’s winning viz.

The construction of my viz was, again, very simple. Five sheets (not including two used in the tooltips). One title. One Parameter. Two blanks (for decoration).

One thing that might be surprising is the complete lack of text boxes, especially considering the amount of text I used. To save some time I made good use of the title and caption boxes for each worksheet, and pasted what I needed into them.

(Admittedly there was one text box, but that was just for my data sources and the hashtag)

Chart types

Feel free to pick my viz apart, there’s nothing complex here either. You’ll find a dot plot with a reference line, five line graphs, and one dual axis line chart (with circles highlighting max & min).


Once I’d decided on the layout I spent forever trying to decide on a colour palette. Here’s a few different versions I tried.

After much deliberation I went all out in emulating the style of economist (where we got the data from) even down to the red rectangle in the corner. I used colour (various shades of red) to highlight which parts were important. There was a good comment from one of the judges, David Pires, on stage. He mentioned that I’d probably overused red on my viz so that important areas didn’t stand out as much as they should, and I’d completely agree with that!


When you’re placing objects on your dashboard I feel they tend to sit a little too close together. One way of getting round this is placing a blank between them and resizing. I prefer to use the padding settings.

Tableau defaults the outer padding to 4 pixels around each. For my viz I didn’t really care what the vertical padding was, all I cared about was how the charts were spaced horizontally. With a click in the centre to unlock the padlock, you can quickly set the values to whatever you want. Once you’ve selected one, pressing tab will take you to the next value.

Technical BitsTableau 

My viz has very little in the way of complexities to it, you just don’t have the time on stage!

  • 6 Calculated Fields

  • 1 Hierarchy (with 2 objects in it)

  • 1 Parameter

If I’d spent a little bit more time thinking, I could have probably put some of these fields into my datasource and saved a bit more time.

The use of a hierarchy was suggested by my Sous-vizzer, Archana. The Big Mac Index data isn’t collected consistently so showing it in a clear and concise way in the first chart proved to be a little difficult. The standard data hierarchy built into Tableau allows you to move through it by clicking the + and – on the appropriate date part.

I wanted my viz to show only the data per year to begin with, but to give people the option to see if per month where the data was available. However I didn’t what the data split per quarter or be able to drill down to the day level, the data just wasn’t there and it wouldn’t look very good. This is where a custom hierarchy is ideal.

Drag the lower part of the hierarchy onto the higher part (in this case, drag months onto years) and you’ve got a fully functional hierarchy that only moves between years and months.

Shortcuts – How to do this in 20 minutes?

There’s loads of quick ways to do things in Tableau, these are few that I used to get my build time down to 20 minutes:

A Mouse

If you think you’re quick with Tableau when you use the touchpad on your laptop, you’ll be twice as fast when you use a mouse.

The Scroll Wheel

Use the scroll wheel on your mouse. There are various different places in Tableau where scrolling allows you skip having to type anything in. Try it on numbers, sliders or drop downs. Hold control to increase the value of each scroll wheel click by 10.

Double Click

Tableau has loads of menus that allow you to edit and format almost anything. Try double clicking on things like axis headers, colour legends, size legends, text boxes, titles, captions and parameters. If that fails to get want you want…

Right Click

Same as above, everything in Tableau is context sensitive. Right clicking on specific objects and specific areas will give you different menus.

Tooltips from dashboard

You can edit your tooltips from the dashboard. Select your worksheet, go to the worksheet drop down at the top, select tooltip and getting editing. This is a little more limited if you’ve got a dual axis and want each axis to show different things.


This shortcut creates a new calculated field

Workbook level formatting

Before you do anything you can choose default font types, colours, sizes. This is in addition to setting line styles and colours. You can even turn them off completely!

Dashboard Containers

This is something I’ve struggled with in Tableau for a long time. I just didn’t quite understand how this particular brand of magic worked. Looking at previous vizzes from the other Iron Viz finals I knew I wouldn’t have the time to make something entirely floating, so I set out in an attempt to figure them out. There’s an excellent video ( by Elena Hristozova at the Tableau Fringe Festival that really helped me, I also spent loads of time just playing around with the containers, sheets and blank. Trying (and failing) to work out what does what. I finally think I understood how they worked when I managed to recreate Piet Mondrian’s – Tableau I


Dashboard Formatting

One part of this I found really useful was the dashboard shading. If you set each worksheet to have its default shading as none, they’ll then inherit the shading of the dashboard they’re placed on. This was a great way to quickly try out different dashboard colours.

Practice & Optimisation

Practice is obvious, once I settled on a final viz I kept recreating it until it was ingrained in my mind. I also tried document everything and put the steps in as efficient order as I could, if you’re curious this is the document I created. It lists all my calculated fields, what they are and where they’re placed. Here’s a rough build order that I followed fairly closely on the day.

Sheet 1 – Dollar Price vs US

Just type into rows



[Choose a Country]

Parameter – list – string – of Country


[Selected Country]

IF [Country] = [Choose a Country] THEN “Selected” END

Colour & Size

[US Price]

sum([Local Price])/SUM([Dollar Ppp])

Detail (as a ref line)

Sheet 2 – Seven Countries

[Price Range]

ABS({FIXED [Country] :MAX([Dollar Price])}-{FIXED [Country]: Min([Dollar Price])})

Rows (as a discrete ATTR)

(As a slight aside here, I have no idea why I decided to include absolute as part of the calculation. It makes no sense! I can only assume it was left over from a previous version. Muscle memory with this sort of thing isn’t always useful, as it only added 5 extra characters to the calculation so I shouldn’t complain too much)

[Max Highlight]

IF [Dollar Price] = {fixed [Country]: MAX([Dollar Price])} THEN [Dollar Price]END

Rows (under measure values)

[Min Highlight]

IF [Dollar Price] = {fixed [Country]: MIN([Dollar Price])} THEN [Dollar Price]END

Rows (under measure values)

[8 Countries]

[Price Range]>4 OR [Country] = [Choose a Country]

Filters (true)

(I was really happy with this calculation!)

Sheet 3 – Average Price – Header

No Calcs needed

Sheet 4 – Oil Price

No Calcs needed

Sheet 5 – Venezuela PPP

No Calcs needed

  1. Connect to both data sets

  2. Format date to read as mmm yyyy

  3. Create hierarchy

  4. Format all text to be Tableau Light, 10

  5. Format headers to Tableau Bold, 16

  6. Format Tooltips to Tableau Book, 14

  7. Create the five sheets

  8. Layout Dashboard (1700 x 900)

    • 4 tiled sheets +

    • 1 header

    • 1 floating sheet

    • 1 floating parameter

    • 1 red floating blank 0,0,30,90

    • 1 white floating blank (as a dividing line) 0, 0, 91, 2

  9. Add a header & footer

    • Whilst the Price of a Big Mac Rises (25 spaces) Crisis Unfolds in Venezuela

    • #IVDaniel |  Data Sources:;;

  10. Padding for the main 4 sheets should be 20,4,20,4

  11. Sort out Actions

    1. Hover Action on Seven Countries to Seven Countries , Measure Names

    2. Menu Action on PPP – Click for more information on purchasing power parity

    3. Menu Action on PPP – Click for the latest Venezuelan Economy News Stories

    4. Sort out tooltips

      • Tableau Book, 14 (the lower part of each tooltip is 18 & bold)

Nice to Haves

In the lead up to the final I was timing each build of my viz, during this week my slowest time was about 23 minutes with my fastest at 17 minutes 30 seconds. At this point I thought it was probably worth including some “nice to haves”, things that could improve my viz but not be required if I ran out of the time. The main nice to have was the viz in tooltips in the final chart on the right. They gave extra context to the Big Mac Index and showed how the value was calculated from the Venezuelan Big Mac price and the US price.

Makeover Monday

Take part. Seriously. I got to that stage because of Makeover Monday and the Tableau community (and Sarah. She introduced me to Tableau back in 2015 and then told me the community existed (I had no idea)).

Though I rarely stick to the recommended hour for Makeover Monday, it’s helped improve all aspects of my analysis, design, storytelling, data viz best practice, and overall use of Tableau.


Maybe add another sparkline in the header, one to go with each half of the title.

I’m not certain the first graph is needed, I could have started with the seven country comparison in the centre and included a deeper level of analysis in the extra space.

Perhaps a bolder colour scheme? I wonder if I went a little too subtle in my choice of colour, though I made it to the stage with a limited use of colour in my Metro Systems viz.

Anya A’Hearn was one of the judges and made an excellent point about moving the story to the start of the dashboard. I could then go into more detail on the right of the dashboard.

But hindsight is a wonderful thing and even if I could travel back in time and make these changes, I’m not sure that I would.

Food Section – Burgers!

So the day after Iron Viz, what better way to celebrate than with a nice burger (couldn’t deal with a Big Mac, it had to be home made!) As it’s barbecue season in the northern hemisphere here’s some tips to make great burgers.

Beef Burger, Sweet Potato Wedges, Tzatziki (I realise this isn’t a typical accompaniment to a dish like this)


Remember to toast your buns! Seriously, it makes for a much better burger experience. Put them cut side down into a dry frying pan until they’re nice a toasty.


Only add salt to the outside of your burgers just before you cook them. If you add salt to the mince before you make the patty it’ll dry out as you cook it.

Basic Burger Sauce

  • One part mayo

  • One part ketchup

  • Dash of garlic powder

  • Some mustard to taste



(I was so happy we got to keep our Iron Viz chef’s jackets, that may have been my favourite part of doing Iron Viz)