Tag: data visualisation

Apr 21 2026

Book review: Ancient Rome Infographics by Nicolas Guillerat, John Scheid and Milan Melocco

There’s no real alternative to a good browse around a bookshop, this book Ancient Rome Infographics by Nicolas Guillerat, John Scheid and Milan Melocco is the result of just such browsing. I’ve been interested in the history of Britain, and the important part the Romans played in it for a while so this was a welcome find. I’m interested in data visualisation, so it’s fair to say this is the sort of exercise I would undertake given data on the Roman Empire!

The authors emphasise several times that the underlying data for these infographics is sometimes uncertain and that there is pretty much no data prior to the fourth century BCE so this period is ignored. They provide an extensive bibliography although it is not referenced at an individual infographic level.

The book is divided into three parts:

  1. The Lands and People of the Empire
  2. Government, worship and social needs
  3. Rome’s military might

The infographics generally span a double page spread, and usually include explanatory text. I’m finding writing a review a bit challenging without reproducing the infographics, the publisher Thames & Hudson have some examples on their product page.

From the first section I liked the visualisation showing the physical extent of the Roman Empire and its growth in both population and area over time. I was surprised to learn that the Iberian peninsula contained a large chunk of the Roman population (5,000,000) compared to 7,000,000 in Italy. The population of Egypt was also significant (4,500,000) although it was absorbed rather later, in 27 BCE. The Roman Empire continued to expand until 150CE.

This section includes quite a lot of detailed information on Rome particularly in terms of the types of buildings in the city, and how the footprint of the city evolved over time. I assume that the Roman remains in Rome have been subject to a huge amount of study hence the large quantity of data. Rome grew to a population of 1.75 million in the 3rd century CE declining to 500,000 in the mid 5th century CE.

Also included are rather complex diagrams of the social and legal classes in Roman society. I must admit I found this less interesting. The authors mention several times that one of the strengths of the Roman Empire was that citizens from all the states across the Empire became fully fledged Roman citizens, as well as citizens of their local state. The social structure was very oriented around voting men, with the paterfamilias – the senior man in a household – essentially holding all of the rights the state bestowed which they distributed as they saw fit to their household. The paterfamilias might also have a patron-client relationship with others outside the household, I suspect this is one of many topics which warrants a whole book to elucidate.

The second section continues with the delineation of roles in society with the focus on the political and government. My favourite part here was the chronology of emperors which also introduced the term damnatio memoriae which is an attempt to expunge an emperor from the historical record. The term, although Latin, was coined in the 17th century. Some emperors had quite long reigns but at other times there were flurries of emperors, or at least those that proclaimed themselves so. This is where the infographic presentation falls down a bit – subtleties are lost because they cannot be presented cleanly. From towards the end of the third century CE there are Eastern and Western empires each with their own emperor and for a brief period there was the “Tetrarchy” – a system of two senior and two junior emperors.

Religion gets a few pages, Romans had a system of public and private “cults” – a city would follow a public cult with its ceremonies and rituals but individuals could also follow their own cult with a shrine and ritual in their home. Later the Christian faith was to spread through the Empire encompassing over half of the population by 350CE.

Also in this chapter is data on the production of grain, and the cost of living. For quite some period the residents of Rome had a “grain dole”, or annona which gave an allocation of grain to selected citizens of Rome (adult male citizens). The cost of living data is so interesting I’m tempted to do my own visualisations! For example 1 rabbit cost 32 as (a small Roman coin) but a pound of wild boar meet was only 8 as. 8 as would also buy you a prostitute but a bath was only 0.25 as. Slaves started at 800 as but went up to nearly 100,000 as for “1 very attractive slave”. A skilled worker could earn 12 as per day, a legionary (a junior rank) 10 as / day, a centurion 165 as / day and a senator 5480 as / day.

The final chapter covers war, I was a bit surprised to learn that the Roman army and navy were not that great but they made good use of local fighters and were good at simply being present. There are descriptions, and infographics of Roman marching orders, camp construction processes and the the evolving equipment of a Roman soldier. I sometimes wonder how accurately such prescriptions were followed, I assume there is at least one documentary source for these processes but how closely were they followed in the field?

I liked the visualisation showing movements of one Roman legionary through his career around Armenia and Eastern Europe. The Social Wars, Punic Wars, conquering Gaul and Spartacus have their own sections in this chapter. I’m assuming these are the most important of the Roman wars.

Overall I enjoyed this book, although I was sometimes frustrated by the complexity of the infographics. It works well as a taster for further investigation.

Feb 16 2026

Book review: The Flawed Genius of William Playfair by David R. Bellhouse

My next review is of The Flawed Genius of William Playfair by David R. Bellhouse. I’ve long had a professional interest in data visualisation, William Playfair is a name frequently mentioned in terms of the invention of several types of chart (line, area, bar and pie charts).

Playfair led an interesting life, fleeing from the French Revolution at one point, and spending several spells in debtors prison.

He was born in Scotland in 1759 and died in 1823. His brothers James and John are notable in the own right as an architect and mathematician respectively.

He apprenticed as an engineer in Scotland and went on to work as a draughtsman for James Watt in Birmingham at the Boulton and Watt works between 1777 and 1780.

It is not discussed in this book but Watt and Boulton were probably close to the origin of engineering drawings as we know them now. They needed them to ensure the parts of the engines they sold, made by multiple manufacturers, would fit together. They also had a business model which saw them paid on the basis of how much money they saved their customers. So Playfair would have a combination of the technical skills required to produce data visualisations, and work for a business that had some call for them. It is interesting to note that another person noted for his innovative visualisations was Charles Joseph Minard, a civil engineer.

Playfair would also likely have had knowledge of Priestley’s Chart of Biography (1765) – a sort of timeline diagram, which plotted the lives and deaths of famous people in history, and the New Chart of History (1769) which showed world history in a similar manner. Priestley was a member of the Lunar Society, as was Matthew Boulton.

At the end of his contract with Watt and Boulton Playfair took on their document copier business, arising from an idea by Erasmus Darwin, patented by James Watt. Playfair seems to have set up the manufacturing process for the machines to a high standard but then left to set up his own business.

This business followed on from the type of manufacturing work that Boulton did, making small metal items with machines. It did not go particularly well, he resumed attempts to set up a manufacturing business on moving to Paris in 1787. His view was that the French were trailing the British in their Industrial Revolution so represented a better opportunity than England, where he would always be competing with Boulton. When in France he also made a proposal to replace the “Machine de Marley” which supplied water to Versailles from the Seine – in this he was unsuccessful. He also set up a bank, as well as being involved in the Scioto Company, which looked to sell land in America to French refugees – an issue here was that the company didn’t actually own any land in America!

Playfair left Paris in 1792, as the Reign of Terror started – he had been peripherally involved in the French Revolution at the beginning but later he became strongly opposed. Supporting the British government in their war with Napoleon – he worked as a journalist, proposed a semaphore telegraph scheme and played some part in a scheme to damage the French economically with a scheme for forging French “assignats” – a form of paper currency used in revolutionary France.

It was just prior to moving to Paris that his writing career started, and his first published works in data visualisation: The Commercial and Political Atlas. The data visualisations were the key novelty here, Atlas uses charts to illustrate economic data. Playfair was showing an increasing interest in economics, meeting Adam Smith in 1787, and also writing a pamphlet on interest rates The regulation of the interest of money. He also edited a version of Smith’s Wealth of Nations after his death.

He also wrote extensively on politics, propounding his views on Jacobins, Catholics, the Irish, and the economy. I was a bit lost here since Bellhouse never tells us what a Jacobin is or the broader historical and economic background. Playfair was in favour of a landed gentry continuing to run the country, and against reform of the parliamentary system. Reviews at the time seem to indicate he was a poor writer with not particularly profound opinions. His British Family Antiquity had the side-effect of bankrupting his publisher, although not Playfair himself (this time).

In his desperation for cash he engaged in low level extortion, effectively writing to people he felt might have money and describing how someone was about to write terrible things about them and he was the man to stop them, for small renumeration. One gets the impression from Bellhouse that this was not uncommon at the time.

Ultimately his attempt to set up a bank in England led to his being imprisoned in debtors prison. His Original Security Bank was established in 1797. It provided notes of convenient denomination in exchange for Bank of England notes. It was clearly designed to take advantage of an evolving situation in banking – the Bank of England had recently stopped exchanging paper money for gold as a result of the war with the French. It presented high “regulatory risk”, in fact the founders, Playfair included were briefly imprisoned for forgery.

As it was the Original Security Bank was quickly wound up, as a result of competition and mismanagement and it is from this bankruptcy that Playfair’s multiple trips to debtors prison arose – the first in 1809. He seems to have come off badly relative to his partners in the bank. Being imprisoned for debt meant that his ability to go into business in future was very limited, hence he leant heavily on his writing. The early 19th century was a different time in terms of how bankruptcy was handled – imprisonment in special debtors prison was routine – a practice that ended in 1869 Debtor’s Act. Playfair formed friendships with other debtors whilst in prison, and these were pretty much the only people he could go into business with – several were outright fraudsters and so this did not go well for him.

In the background to all this he was married to Mary Morris possibly in 1780 when their first child, John, was born although wedding banns were read for them in 1795. They had four children, one of whom was blind and thus needed support throughout her life. One wonders how much Playfair was responsible for the financial support of his family.

I have mixed feelings about this book, it is pretty readable but although the author mentions and illustrates Playfair’s work on data visualisation one gets the impression his interest is more in economics, politics and debt. This may simply be an accurate reflection of Playfair’s life but I was more interested in the data visualisation side of his career.

Aug 17 2024

Book review: Daphne Draws Data by Cole Nussbaumer Knaflic

I recently reviewed Cole Nussbaumer Knaflic’s Storytelling with data, as a result the storytelling team sent me a (pre-publication) copy of their latest book, Daphne Draws Data scheduled for publication 29th October 2024 (UK) and 4th September 2024 (US). This is something of a change for me in the sense that the book is targeted at teaching data visualisation to the 6-9 year old age group. I am 54 – however, I have a 12 year old son and an interest in education. I have never reviewed a book intended for children before.

The first thing to say about this book is that it is beautifully illustrated by John Skewes. As I write this review Daphne (a dragon) is looking out at me from the cover of the book which has put a smile on my face.

The book follows Daphne as she visits various locations, and helps the creatures she finds there by collecting data and drawing graphs (having first reassured them that she was not going to incinerate them!). This is very much like my own career. I particularly liked the visit to the ocean where she draws a graph showing that shrimp and crabs move at the same speed if you allow for the size of the creature. This is quite sophisticated scaling analysis that I’ve taught to undergraduate physics students.

The book finishes with a glossary of chart types which is reminiscent of the material in Knaflic’s books for adults. I was slightly disturbed to see the caption “Eat a rainbow” close to an illustration of some coloured crayons but it is an exhortation for children to record the colour of the food they eat during a day and make a bar chart, rather than eating the crayons!

A children’s book fits very well with the central theme of Knaflic’s work on data visualisation which is the importance of storytelling. To be honest working out who is eating the monkey’s bananas is more engaging than the usual stories we tell in our business presentations.

I guess a key feature of books for children in this age group is that they are read with an adult, I imagine a lot of adults would learn from it too.

Alongside the book there is a website daphnedrawsdata.com which includes resources for educators, amongst much else. This shows how the book fits in with the Common Core requirements in the US school system, I’m sure this will align pretty well with the UK standards.

I’d have definitely bought this book during the COVID lockdowns as material for home-schooling, not only does it cover some data visualisation techniques but it also encourages the data collection that has been central to my life as a scientist. I’d probably also borrow the illustrations for any presentations (to adults) I might give on data visualisation.

Aug 11 2023

Book review: Storytelling with you by Cole Nussbaumer Knaflic

I recently reviewed Cole Nussbaumer Knaflic’s Storytelling with data, as a result the storytelling team sent me a copy of Storytelling with you to review. Storytelling with you is the next step in the journey which started with Storytelling with data, widening the scope to talk more fully about the whole process of presenting from inception to delivery and not being concerned specifically with presenting data.

I’m a data scientist, previously an academic and then industrial research scientist. Presenting has been a constant throughout my career, both as an audience member and as a presenter. Yet it is something in which I have had relatively little training and given the quality of the presentations I have witnessed – I am not alone!

Those with a scientific background will be used to a standard way of presenting results that effectively replicates a scientific paper (introduction, methodology, results, discussion, conclusions). Knaflic’s earlier book proposed a break from this format: using ideas from storytelling to shape presentations. She cites Resonate by Nancy Duarte, as a reference for this approach. Storytelling with you is similar in content to Resonate but feels like a shorter, more focussed book.

The book is divided into three parts: plan, create and deliver. Each part comprises four chapters. Each chapter ends with an instalment of the “TRIX Case study”. TRIX is a trail mix product which requires revision and the presentation is about options for this revision. I really liked this, it enables Knaflic to provide examples of the material in each chapter without having to restate the context for each new outing. I have learnt that macadamia nuts are really important to the TRIX mix!

Planning starts with the audience, not the content. Who are they? What do they want? I find Linkedin is great for getting a quick view of audience members. In terms of content the plan starts with the Big Idea – the sentence that captures what the presentation is about. This is expanded into a full story using a storyboard based on Post-its.

Knaflic is keen on Post-Its for planning and organising material. My tendency when creating a presentation is to open up a PowerPoint file but this forces me into choices on format and so forth that I don’t need to make at the beginning. There is also a challenge in being unwilling to delete slides so carefully and laboriously created!

The section on the theory of storytelling is quite brief. One takeaway for me was to think of the children’s books you know as templates for storytelling. Over the last 10 years or so I have read a lot to my son so I am very familiar with a range of children’s books. I like Dr Seuss, and Julia Donaldson’s books – The Gruffalo, for example – not only do they provide a template for stories, they are designed to be read aloud and provide some ideas for delivery. For fun, you can even think about your presentation in the style of Dr Seuss!

The create section is very practical, including a walkthrough of how to use PowerPoint-like Slide Master – I found this welcome since whilst I am aware of the master slides my use of them is rather primitive. It also talks about font selection, picking a font which has a distinct bold form, and colour selection.

The appendix containing the completed slides for the TRIX case study is quite telling when I compare them to my own: the case study slides contain far less text and effectively no bullet points when compared to mine. The story of the presentation is read from the titles which summarise the slide they sit on rather than indicating the function of the slide.

In terms of content I found the section on images most interesting, corporate templates tend to have a bunch of images included, and I always feel the need to add an image to each slide – which is wrong.

There is a substantial section on delivery. I found the part on introducing yourself quite striking, it talks about picking out the characteristics which you wish to present and relating anecdotes that support them. I found this a bit calculated but realise I probably do this intuitively – I am notorious for my anecdotes!

I was bemused by the vision of Knaflic striking power poses in conference centre restrooms in preparation for presenting! She provides a lot of detail on how she prepares to deliver a presentation. I learnt long ago that practicing the opening is very important, I find it helps me to relax. Knaflic points out that practicing your ending is equally important – it sends your audience off into action.

In common with Resonate and Storytelling with data  the assumption is that you are preparing for a high stakes meeting and you are going to commit a lot of time to this process. Typically I find I make lots of low stakes presentations so there is a degree to which I would adapt the lessons in this book to that scenario. In fact the storytelling team have recognised this, and produced a blog post on a reduced process.

If you’re looking for a readable guide to planning, creating and delivering presentations then this is the book for you!

Apr 17 2023

Book review: Data Points by Nathan Yau

data_pointsI picked up Data Points by Nathan Yau as a recommended book on exploratory data analysis in Storytelling with data. I have previously read Nathan Yau’s book Visualize This.

Visualise This  was very focussed on the technical side of producing data visualisations, with code samples and so forth. This is a “bigger picture” book divided into three sections: context, exploration and presentation.

Context can be summarised as: who, how, what, when, where, why. Context is covered explicitly in the first chapter using the medium of Yau’s wedding photos as an example. Spinning off from here is a mention of the Quantified Self movement, there was a time a few years ago when this was popular – people would record aspects of their life in great detail and build visualisations from them. This was enabled by the growth of the first generations of smartphone which made this sort of data collection easy. Yau points out – and I think all data scientists can agree with this – that most of the job is actually collecting together the data required for a project and getting it into a shape to visualise.

The “Exploration” chapters start with an overview of what a data visualisation is, one of the strengths of this book is the many examples of visualisations, in this case going as far back as William Playfair in 1786 with the invention of the bar chart. This chapter also highlights that a data visualisation can be a flow chart, or it can be an abstract piece of art which is based on data. Yau cites John Tukey’s Exploratory Data Analysis a number of times which was published in the 1970s at a time when the author felt the need to explain that a “bold” effect can be achieved using a pen rather than a pencil. The point being that we now have immense power in readily available software to produce visualisations at the click of a button which would have taken an expert many hours of manual labour in the relatively recent past.

The next chapters provide a summary of how we build a data visualisation starting with the fundamental building blocks: title, visual cues (the data), coordinate system, scale and context elements. The visual cues are further broken down into attributes like position, length, angle, direction, shapes and so forth.

Once this groundwork has been done, there is an extensive taxonomy of chart types including more esoteric plots such as the cartogram (where geographic areas are distorted to show the relative sizes of variables), and radar or polar plots which, along with calendar heatmaps are useful for showing periodic timeseries data.
The “Visualising with clarity” chapter starts to talk about presentation, and how the purpose of visualisations is to allow comparisons. I think the useful takeaway from this chapter for me was that distribution plots are rather more difficult for the lay viewer to interpret than practitioners realise.
I found the penultimate chapter on “Designing for an audience” a little brief. A handy hint here was to design presentations for the audience at the back of the room – nobody likes to hear “this is probably too small for you to see” from a speaker. Another useful tip for making interactive presentations is that people like to find out about themselves, so if you have data on people then make it easy for viewers to “look themselves up” because that’s the first thing they are going to do.

The book finishes with a chapter on technologies, some of them such as R, Adobe Illustrator, Microsoft Excel, Google Sheets, Tableau are still around and remain good choices. Yau’s favoured combination is R with Adobe Illustrator used to polish the results. The Javascript library Data Driven Documents (d3) and Processing are still active. Other systems like IBM’s Many Eyes project, MapBox’s TileMill have disappeared. Javascript Libraries Raphael and the Javascript Infovis Toolkit appear dormant, in the sense that the activity on their GitHub repositories is minimal. Nobody talks about Flash and ActionScript anymore.

Data Points is much more a book about exploratory data visualisation then Storytelling with data, I think Yau believes that exploratory data analysis is an exercise in storytelling. The strength of this book is the wide range of examples used to illustrate the points being made through the book. The style is chatty, it is not a difficult read. It is less focussed on delivering specific lessons in making data visualisations than Storytelling with data.