Make grey your best friend

Anybody facing up to colour choices in any creative activity knows how critical such decisions can be, making a big difference between the success and failure of a design. This is amplified in data visualisation. In contrast to graphic design work, for example, there is unquestionably a greater need to eliminate or at least reduce arbitrary choices. The use of colour to decorate work or to sprinkle colours that we simply like have to be the final considerations – never the first – once all the other functional applications of colour have been implemented.

When considering these more functional applications, one of the most reliable and versatile colour options is grey (regardless of semantics about whether it is a colour or a ‘colour without colour’, see more). The advice I often give out to folks in my training workshops is to make grey your best friend when colouring your visualisation work.

Let me illustrate why with a few simple examples:

Accentuate for focus

In the ‘Fertility and life expectancy’ graphic (the accidental Reindeer chart?) below, created by Moritz Stefaner in his ‘Remixing Rosling‘ project, colours are used to accentuate the US and Vietnam patterns. This highlighting effect is made possible through the relationship between the two colours and ‘no-colour’, the use of grey for all the other country plots.


Create reference for judgment context

In this next display – the bullet graph conceived by Stephen Few – we see the value of grey scale in creating a reference for interpretation. Any given black bar represents a quantitative value that can be read alongside the various grey shaded background thresholds. This provides the context of meaning – is the value good, bad or average, for example.


Create reference for positional context

In a similar way, this example of Bryan Christie’s exceptional scientific illustration work uses a contrasting palette to highlight the focus on the heart. Through the use of greyscale (almost an x-ray style look) to illustrate the overall anatomy, this allows us to understand the positional context of this organ without subtracting from the focus.


See the overall shape

In this neat multi-line chart below, by Maarten Lambrechts, we see historical readings of temperature in Belgium, one line for each year, across the 12 months of the year. There is a triple benefit in using grey in this work. Firstly, we can draw focus on a given year by hovering over a line and having colour help bring it to the forefront. Secondly, the inclusion of all data in one display for context allows to judge whether the selected series is higher, lower or typical of the rest of the dataset. Thirdly, by using a neutral colour like grey we can see the big picture – the overall shape and pattern of the data – surfacing the seasonality and spread of values, without colour getting in the way.


Layout organising device

This sample dashboard by Welovroi demonstrates how grey can be used as an elegant layout/organising device, to subtly separate the various panels of the display without the need for shoutier backgrounds or intrusive borders.


Show what is unselected

This sample interactive work by Raureif and Christian Behrens, showing energy flows, is just one of endless examples whereby grey is used to display features or values that have been momentarily unselected or excluded whilst leaving them visible for reference.


Placeholder for null

Finally, an example of using grey almost as a placeholder colour for zero or null values. In this ongoing Bloomberg Billionaires project those people for whom we have no recent photos or visual depicting how they look are presented as a grey, blank face placeholder in contrast to all the other illustrations. This in turn creates some intrigue as to why we don’t know what they look like (reclusive billionaires have a certain extra mystique…).


Talk slides from ACHep: Communicating Through Data

I was honoured to be invited to speak at the Alliance for Continuing Education in the Health Professions Annual Conference for 2015 event in Grapevine, Texas. The title of my talk was commissioned by the organisers ‘Communicating Through Data: Visualising Your Story’ and below are the slides I presented. If you have read my previous talk ‘Let’s do some thinking about visualisation thinking‘ you’ll see many similarities. Also, if you’re attending my upcoming talks at Astra Zeneca or PyData (see, speaking events) maybe sit this one out so as not to ruin the upcoming magic :)

Turn off the sea if you’re not using it

In an attempt to increase my blog post frequency, this year I’m going to publish more smaller posts that try to impart morsels of advice or thought-provocations about certain visualisation design matters. No deep dive theoretical exploration, just some practical tidbits most probably relating to quite narrow design considerations.

I’m going to start off 2015 focusing on a long-held gripe I have with map-based visualisations that colour the sea.

A tweet popped up on my timeline earlier from Max Gadney @aftertheflood commenting on a pair of maps comparing immigration levels with high numbers of UKIP voters in the UK.


You’ll see the map on the left has a large amount of clutter created by the unnecessarily coloured sea. As Max correctly recommends, we don’t need to draw such prominent salience to the sea, it has nothing to do with this data display. It also makes the judgment of colour scales within the left map harder (and obstructs the comparison with the right hand display, which has no sea colouration). A colour judgment made against a backdrop of a saturated colour can lead to very different perceptions compared to a backdrop of white.

We almost never have a need to care about the world’s seas and oceans in a display about geospatial data. In the majority of occasions the data relates to things that have a ‘land’ relationship. Yet, so often we have these big saturated areas dominating our view with nothing more than decoration.


It is especially problematic if blue is used for the sea but blue is also being used for a quantitative or categorical colour scale within the map. We have mentally committed to reading blue as meaning the sea but we now have to contend with an additional association.

The only times we usefully need to colour the sea are when there is visual relevance in the relationship between land and sea (usually distinguishing with an emphasis on what is land) OR the focus of your data portrayal concerns what is happening on or over the sea, like the patterns of wave heights or shipping routes seen in the below.




If you’re not going to use the sea for these reasons then turn it off or at least turn it down.

In defence of spreadsheets and our craft

Last week there was an article on Wired profiling an upcoming tool from Tableau called Elastic, which drew my ire. The tool looks fine, haven’t seen a great deal about it but I’m sure it will find a user base.

What initially caused my Roger Moore eyebrow to spring into action was the way the article framed the tool. Check out this tweet from Wired.


“Spreadsheets are awful”. Just plain ignorance.

Spreadsheets are incredibly valuable tools for handling data, undertaking calculations and analysing it. They are not the most powerful of statistical analysis tools but they often provide enough. They are not the most potent charting packages, but they often provide enough. They are a fundamentally useful ally.

When someone emails a spreadsheet to your iPad, the app will open it up—but not as a series of rows and columns… The hope is that this will make is easier for anyone to read a digital spreadsheet—an age-old computer creation that’s still looks like Greek to so many people.

Sure, people do produce and share some really impenetrable workbooks. They dress up tables of data with the most horrendous shading and bordered decorations. However, as with bad PowerPoint slide decks, it is so lazy and easy to blame the tool and not the creator. What if I wanted the table of data un-visualised? Maybe I want to use the raw data as it comes, maybe I want to perform a lookup-and-reference type of interpretation? We don’t have to nor do we want to visualise everything. Let’s be more discerning than that.

That was the first thing. The second thing that caused my beef was the angle used to substantiate this type of tool as a kind of panacea that will automate and (that most dreadful of words) democratise the role of visual analysis.

So many companies aim to democratize access to online data, but for all the different data analysis tool out on the market, this is still the domain of experts — people schooled in the art of data analysis. These projects aim to put the democracy in democratize.

I don’t even know what that last bit means. Surely that would lead to democracytize?

These kind of confused articles bluntly reduce the craft of data visualisation, data science and data journalism into the most simplified of disciplines, something that an automaton should operate. They smooth over the complexities of working with data in a way that only existed in the idealised scenario offered by Microsoft’s practice ‘Northwind’ database.


The hope is anyone can become a kind of data scientist — using data in ways that echo so many journalists these days, from Nate Silver on down.

A “kind of data scientist”. “Nate Silver on down”. Wonderful, sign me up, I’m sold.

Finally, as Andy Cox pointed out, can we also please drop the Joey Tribbiani quotations wrapped around “visualize”.

The Seattle-based company has been massively successful selling software that helps big businesses “visualize” the massive amount of online data they generate

Talk slides from The Design of Time

I was immensely grateful to be invited to speak at yesterday’s excellent conference event in London. As I previewed last week, the title of my talk was ‘The Design of Time’. With only a 15-20 minute slot I couldn’t possibly fit in everything that I wanted to profile (indeed I probably shouldn’t have attempted everything that I DID profile) and so here is a director’s cut version of yesterday’s talk.

Preserving and archiving digital visualisation

I’ve had this issue on my mind for a while now but haven’t really found a way of expressing a cohesive post about it. I still haven’t, as you’ll find by the time you reach the bottom. Let me state from the outset: today, I am the problem guy, not the solution guy. However, I felt I’d pondered for long enough and so decided put this out there to trigger some further thought and discussion.

Digital preservation

As we will all know, the work emerging from the contemporary data visualisation field is dominated by digital output. Of course, there is still a significant amount produced for print consumption but, ever-increasingly, data visualisation is a digital – made-by and made-for – pursuit.

The history of the field preceding this recent era had a legacy of work that was easily archived and replicated for viewed in books or libraries. But how do we preserve the incredible array of digital data visualisation work being produced by this and future generations? It is an issue that goes beyond just safeguarding URLs and certainly goes beyond just the field of data visualisation.

Last evening, there was a terrifically astute stream of tweets from The Upshot’s Derek Willis, discussing web/data journalism, that articulated the concerns perfectly

Digital archiving

As I perused some of the many tremendous web-visualisations tracking the recent US mid-term elections I was struck by the fleeting status of a graphic being fed by live data updates as they occur. As the story of an election night unfolds there will be all sorts of interesting ebb and flows, different points where the story arc seems to be heading in different directions (maybe not in this particular election but you get the point).

As soon as the new data comes in, the composition and content of that live graphic has changed.

This is not unique to elections of course, any real-time or frequently updated visualisation.

Over on Bloomberg they have the excellent Billionaires project, with a daily update on the fortunes (absolute and changing) of the world’s rich.


What is interesting about this project, as Lisa Strausfield discussed in Data Stories episode #41, is that Bloomberg has journalist resources assigned to stories around billionaires. It’s a matter of common interest and intrigue so why not. Perhaps because of this dedicated resource there is a daily archive of the status of the billionaire’s rankings project for any given date (eg. 11th April). So it is very easy to revisit a point in time and see how person x did on that day

Not every real time project will have that resource, nor will it have a subject matter that has levels of potential interest that endure on an ongoing basis. So what can be done for those projects?

Another example of the preservation challenges. It sounds like soon (or even already) parts of the US will be getting very cold. I saw this tweet with a still snapshot of the live ‘Earth‘ weather map visualisation by Cameron Beccario.


Seduced by these patterns I also took a look at the display on the ‘Wind Map‘ and took my own screenshot to preserve that data ‘moment’.


I’d forgotten that the Wind Map project does have an archive gallery of previously interesting or noteworthy weather events.


However, that gallery has not been updated since Hurricane Sandy in October 2012.

As soon as this latest weather system passes, those interesting patterns are gone forever. Unless someone archives them.

When mapping spatial data really makes sense

As the final members of the graphics teams (1, 2, 3, 4 etc.) across the news media finally shut down their machines after a long night of mid-term election coverage, I am reminded of a great article by Matt Ericson from 2010 titled ‘When maps shouldn’t be maps’. (Addition: A very helpful ‘Map or Don’t Map‘ flowchart from John Nelson at IDV)

In this article Matt describes the need to be more challenging in our natural assumption that simply by having spatial data we should map that data: “the impulse is since the data CAN be mapped, the best way to present the data MUST be a map”. If the interesting patterns are not spatial then a mapped display is fairly redundant. We may learn more from a location-categorical display comparing quantities or how values for those locations have changes over time, ranked by the largest to smallest changes, for example.

However, on the flip side, when the interesting patterns ARE spatial, then of course, the layering of a data display on to the apparatus of a ‘map’ makes complete sense. Over the past week I have come across two different but very effective examples that demonstrate this.

Firstly, a very revealing visualisation (Alberto’s viz of the week, no less) about ‘Obama’s Health Law‘ by the New York Times. The map displays the percentage point increases, county by county, of Americans with health insurance under the Affordable Care Act.


I don’t know a great deal about the Affordable Care Act, particularly the political mechanisms that make it available or otherwise, but from looking at the display you can immediately see regional discrepancies that MUST be reflective of state level policies. Reading the accompanying article explains this observation in further detail:

That state boundaries are so prominent in the map attests to the power of state policy in shaping health insurance conditions. The most important factor in predicting whether an American who had no insurance in 2013 signed up this year was whether the state that person lives in expanded its Medicaid program in 2014.

By way of illustration, the piece draws contrast between Kentucky, which expanded Medicaid, and Tennessee, which didn’t. This was something highlighted by Lena Groeger on Twitter


There are many other spatially significant differences that support the benefit of displaying this data (albeit, just one view or one slice of analysis about that data) via a map: It reveals interesting patterns that would not have been as effectively or efficiently portrayed using other approaches.

The second example I came across concerns a different idea of mapping, this time the mapping of the geography of the human body. The graphic ‘Bumps, Bruises and Breaks’ by the Wall Street Journal – originally found on Junk Charts – shows how NFL players have sustained over 1300 injuries this season and where these injuries occurred on the body.


Plotting the quantitative displays of injury totals across the different parts of the body makes complete sense. It is more concrete, you can see the distribution more instantly. By having the illustrated player in the background you can also draw conclusions about the sufficiency (or otherwise) of the protection they get from their kit. Incidentally, Kaiser does a great job of offering up some further enhancement ideas for the graphic.

So in conclusion, just because you can map your data, doesn’t mean to say you should. Have the discipline and sense to challenge your natural impulses but, when it does make sense to do so, plotting spatial data on a map can really illuminate the inherent patterns.

Talk slides: Thinking about data visualisation thinking

Below you will find an embedded slideshare version of the slides used in last week’s talk at the Data Visualization Group in the Bay Area Meetup at the University of San Francisco. As usual, the quality of the slide images hasn’t quite been preserved in the upload but you’ll get the idea at least.

I always say this and will say it again: presentation slides are just visual props for a talk so you won’t be able to necessarily decipher the exact narrative that accompanied each subject. For meetup members (and maybe those not present too, possibly) the video of the talk should be released soon. I might also trot out the same talk at another future opportunity so do have a look through/watch but don’t memorise it, just in case!

I have edited one or two of the slides for the purpose of sharing this deck publicly. For instance, this was my original slide 2, capturing the idea that I regretted that my talk title was a bit too Troy McClure-esque.


The thinking behind Visualising Data 2.0

A new dawn

That might seem like a rather a pompous section header – after all it is just a new site design – but for me it feels like a really significant milestone. The new version of was launched yesterday without too many bumps in the road, thankfully. I want to share a little bit more information about the thinking behind this new site’s design and functionality. I appreciate all the feedback and comments that have been aired so far and hope this responds to some of the curiosities that were expressed.

Motivation for change was launched in February 2010 shortly after I graduated from a Masters research programme that had enthused me to want to continue to learn and discover much more about the data visualisation field. I decided that setting up a quick and lightweight blogging platform like WordPress and writing publicly about the subject was a great way to continue learning. You are forced to research, think and carefully establish your convictions.

At that time the field was experiencing a very evident increase in popularity and mainstream coverage. (I will always look back as being very fortunate to arrive in it when I did). Over time, as the field has continued to mature and spread, hopefully, the site’s content has reflected a similar development providing value to new enthusiasts and seasoned pros along the way.

I was always mindful that the look, feel and functionality of the site was somewhat stuck in the vertical, scrolling wilderness of the particular WordPress theme I’d chosen. New stuff gets seen, older stuff gathers dust. It did an entirely worthy job for a long time, particularly prior to me a being a full-time freelance professional, but over the past couple of years I’ve felt an increasing friction between the style of the site and the things I’m teaching, preaching and practicing. As a shop-window to what I’m about it was no longer a good enough fit.

I don’t have sufficient web programming literacy to do much more than tweaking so any significant development have been very hard to find space to move up the priority list. However, at the end of 2013 I decided the time was right to draw together a brains trust and start working towards an entirely fresh design. Not only a website reboot but something that extended to a whole new visual design and brand identity across all outputs.

Whats on this site

Here’s an outline of the contents and features that you will now find on the site.



Creating a home page was one of the most important additions I wanted to introduce in this new version. I wanted to move away from the home page being the beginning of a stream of blog posts. This very final single image of what was essentially the previous home page view is illustrative of the old experience. I was also seeking a more dynamic front landing page that would encourage people to explore different parts of the site and offer a slightly different experience each day they come back to the site. I accept many people still tend to consume site content through RSS, google discoveries and links from social media but it is still nice to be able to offer a home page experience for those new arrivals and/or those who stick around for a browse.

So, on the home page you will find a convenient profile of the latest and most relevant content on the site.

We are still exploring ways to ensure the layout and functionality is optimised for large screen vs. small screen, for desktop vs. mobile/tablet. More on this further down.



The blog posts on this site date back to February 2010 and are really the heart and soul of this site. As I’ve already described, one of my motivations was to make the older content more immediately visible and accessible, getting away from that very linear, vertical journey of the previous WordPress template. Now you can move around nearly 5 years of content in just one or two clicks of the button. You also have the featured images to better inform your browsing choices and preview text to decide whether to continue to visit the full article. The blog page takes a couple of seconds to load up the content of the database – we’re going to continue looking at ways to shave time of this loading. The content is presented in reverse chronology and is categorised by seven content groups.



For the individual blog posts there is now a cleaner design with a more striking banner image for each blog (with the flanking colours auto generated from the dominant image colours to blend in) and a more integrated ‘related posts’ feature. The comments are tidied away until you wish to view them and you can browse backwards and forwards, as usual, to proximate posts. The social media buttons enable the sharing of the post links to the main 4 destinations. The tally counts for each post have hopefully been pulled through in most cases but some have not.

In my current blog post database there are 529 published posts. In the process of migrating to this new site design I have had to go through each post to reconfigure it slightly, set up excerpt text, update to the new categories and also assign a featured image. I have managed to get through over half of these but still have 200+ to complete so you will see some blank tiles in the blog page and in the blog posts themselves a ‘Page Under Construction’ banner image. I’ll be working through these as quickly as possible to tidy up all the content.



The collection of resources has been one of the most popular content items published on the site down the years. This page now provides a interactive navigable database of over 200 tools, applications and programmes that have an important role to play in data visualisation design. As new tools arrive on the scene, this collection will be kept entirely up-to-date to maintain the latest catalogue of options: I will shortly be finally getting round to the extra 70/80 or so outstanding items that need adding. The categories are a best fit grouping, though some tools inevitably do cut across several in scope. The preview text wording is often drawn from a tool’s native site, rather than being my own. Also, I may not have actually used all the tools, I may not even personally think all of them a particularly great, but I will have seen evidence of others who have endorsed them or found them useful in different contexts to make them worthy of including in this collection. I would also like to take the opportunity thank Tableau Software who are the exclusive sponsors of this resources page.



The references collection provides further useful resources for data visualisation enthusiasts. As above I will endeavour to add all the outstanding content that I’ve been bookmarking as soon as possible and keep it more up-to-date going forward. Some of the background widgets we have created in the WordPress admin dashboard will make this task much easier than before.



This page provides an overview of the data visualisation training workshops I run on behalf of Visualising Data Ltd. There is an overview of the training content, a profile of the types of training available, a list of the current training schedule, an interactive map to explore the location and type of previous events, a selection of participant testimonials (still needs another 100+ adding) and a form for interested parties to make a request for a future event. I am still exploring the potential use of a new training event registration tool (as an alternative to Eventbrite) that will be more integrated into WordPress.



The services page presents the range of professional services I offer on behalf of Visualising Data Ltd covering consultancy, research, teaching, speaking and writing. There is also a gallery showing the logos of previous clients.



This page promotes details of my first book ‘Data Visualization: A Successful Design Process’ and, as the development progresses, will also eventually show information about my second title.



The about page profiles me, provides an outline of the workings and content of this site, some brief details about Visualising Data Ltd and a contact details page with links to my more prominent social media profiles.


The type used in the new site includes Exo 2, used mainly for titles and headings, and Raleway, mainly for the body text. The colour palette was developed by Matt (see below) and comprises the following:


“Every screen according to its needs”

As with any worthwhile site development, we have sought a solution that works as well as possible across all platforms. There is a view that modern web site design should have a ‘mobile first’ objective. I recognise and agree that content is increasingly shared and accessed from smaller, mobile devices. However, my motivation for the redesign of this site has been focused foremost on an enhanced desktop experience, translatable where possible to tablet and then stripped back to be as accessible and light as possible for mobile. You will not see the same level of functionality available on a mobile browser compared to desktop because the screen real-estate and scope for interaction doesn’t lend itself to achieve this. This tweet and comment from Al Shaw expresses my views perfectly: “Instead of ‘mobile first’ I like ‘to every screen according to its needs'”.

This does not mean that there is not more work to be done to maximise the effectiveness of the design across the different platforms, we have several things to fix and possible avenues to explore to make the site as responsive, accessible and well-performing as possible.

The brains trust

This photo was taken at the first project meeting between myself (camera operator), Andrew Witherley (left) and Matt Knott (right) in October 2013.


Matt led the way in facilitating the new design thinking: developing the new branding ideas around logos, typography and colour palette and helping to formulate the initial mockup sketches ideas of the site. Matt will be contributing to a future article about the thinking and design process specifically behind the new logo.

Andrew led on the development side, bringing his considerable technical talent and sharp eye to entirely translate my hopes for the site’s structure and capability in to reality. Over the past few months especially he has gone above and beyond to help me get over the line with this new launch, particularly as my often limited spare capacity has led to a very stochastic pattern of progress.

Its been an immense pleasure working with both of these splendid chaps and I am hugely grateful for their contributions.

Re-using custom graphic archetypes

One of the (many) things that impresses me most about the quality of data visualisation and infographic output from the leading journalist organisations is the continued variety and innovation of their techniques. Rather than just being constrained by a limited visual vocabulary, each new work published tends to feature a solution uniquely suited to the data, the analysis and the subject matter involved. Given the pervasive time constraints involved, the work we see created, day in day out, is quite incredible.

Of course, on special occasions, there is a compelling reason to potentially re-cycle previously used graphic archetypes and there was an example of this last week that was both astute and highly impactive.


Firstly, to explain what I mean by re-using custom graphic archetypes. I’m not talking about the repeated use of an off-the-shelf chart on numerous separate occasions, like the bar or the line chart, I’m referring to more bespoke solutions that have been used for multiple projects.

The New York Times, for example, utilised this interactive and participative matrix to assess the public’s reaction to the death of Osama Bin Laden back in May 2011.


They then, quite correctly, used the same underlying graphic approach to assess the reaction to Barrack Obama’s stance on same-sex marriage. Why reinvent the wheel when you’ve got a perfectly applicable solution on your shelf?


In another example, The Guardian launched their innovative interactive timeline in March 2011 to outline the key milestones and sequence of events related to the Arab Spring.


In June of the same year it was re-imagined as a timeline to show the evolution of modern music…


…and again in October 2012 to show the events leading to the Eurozone crisis. An entirely reasonable, appropriate and – importantly – effective choice.


Whilst it is not purely the same archetype being re-used, last week’s ‘How high can a missile reach?‘ graphic published by the Washington Post (by Bonnie Berkowitz, Julie Tate and Richard Johnson) had a more profound effect. This was a vertical-scrollable graphic that aimed to show the scale of the height involved in the tragic shooting down of the Malaysia Flight MH17. I’ve recorded a brief video of it below.

As I mentioned on Twitter last week, there is something so haunting about the juxtaposition of the ‘how high’ graphic considering just three months earlier, the Post produced a ‘how deep’ graphic showing the ‘The depth of the problem‘ (by Richard Johnson and Ben Chartoff). This was a very similar graphic device used to show the scale of the depth involved in the search for the Malaysia Flight MH370 black box.

Once again, the appropriateness of the same graphic approach being used is without question. The switch from height to depth, from upwards scrolling to downwards scrolling, to visually capture the essence of two so-closely-linked tragedies was very cleverly conceived and had a big impact on me.