Data Points: Visualisation That Means Something. By Nathan Yau. Wiley; 300 pages; $32 and £26.99. Facts are Sacred. By Simon Rogers. Faber and Faber; 311 pages; £20. The Infographic History of the World. By James Ball and Valentina D'Efilippo. Collins; 224 pages; £20. IN THE late 1700s William Playfair, a Scottish engineer, created the bar chart, pie chart and line graph. These amounted to visual breakthroughs, innovations that allowed people to see patterns in data that they would otherwise have missed if they just stared at long tables of numbers. Big data, the idea that the world is replete with more information than ever, is now all the rage. And the search for fresh and enlightened ways to help people absorb it is causing a revolution. A new generation of statisticians and designers - often the same person - are working on computer technologies and visual techniques that will depict data at scales and in forms previously unimaginable. The simple line graph and pie chart are being supplemented by things like colourful, animated bubble charts, which can present more variables. Three-dimensional network diagrams show ratios and relationships that were impossible to depict before. Fernanda Viégas and Martin Wattenberg, co-directors of Google's "Big Picture" visualisation research group, lead the field. In their animated online infographic, "Wind Map" (pictured), which was created in 2012, they took hourly data from the National Digital Forecast Database to show windflows across America. The intensity of the white lines represents the gusts" force. The result is a unique way to show near real-time data in a way that is both informative and elegant. For that is what data-visualisations are: a blend of the aesthetic and informational. Having one without the other means producing something that is less useful and enjoyable than it might be, argues Nathan Yau, a statistician who runs a blog called FlowingData.com. Visualisation is a whole new medium, he writes in his new book, "Data Points." It is a "continuous spectrum that stretches from statistical graphics to data art." Translating data into images allows people to spot patterns, anomalies, proportions and relationships. When done well, it lets the eye create the narrative; people teach themselves, rather than being told. Neurologically, humans use a different part of the brain when information is presented visually rather than through numbers. The right hemisphere handles imagery; the left is more analytical. Seeing data pictorially makes good use of both sides of the brain and lets one grasp meaning more quickly. Mr Yau's book does an excellent job of explaining what makes a good data illustration. In the past, this would have been the sort of stuff that might appeal to graphic designers. But today every professional interacts with data and charts, be it by poring over a spreadsheet, watching a PowerPoint presentation or reading a newspaper. The book walks the reader through myriad examples - world airline routes, road deaths across America, even the distance to the nearest McDonald's outlet - to explain what works and why. In one section, for instance, a dull table of American educational statistics is visualised in 20 different ways across 12 pages to unleash vibrant insights that had been trapped within the rows and columns. Who knew that Washington, DC, saw the biggest improvement in high-school graduation rates between 2000 and 2009, while Texas fell to the bottom of the ranking? "Data Points" is a useful primer for those who need to produce infographics. But for those who merely want to appreciate them, two other books fit the bill, both by Guardian journalists. In recent years the London-based daily newspaper has promoted a new area called "data journalism." The idea is that reporters must interrogate both people and databases in order to get their information. Simon Rogers's "Facts Are Sacred" is a review of the past few years" worth of this data journalism on the paper's website. It brings together some of its best projects and explains how they were done. The high-water mark was the way the newspaper handled the classified American information released by WikiLeaks in 2010. It took thousands of American field reports from Afghanistan and extracted information on those involving "improvised explosive devices" (IEDs). It then mapped where and when explosions took place and the number of casualties - so that viewers could explore the data and see changes over time. The result was an interactive infographic that described an aspect of the conflict through data alone. The most dangerous area, it turned out, was the south, where British and Canadian troops were based. The best work in Mr Rogers" book is very good indeed, but the mean is low. In too many cases the colourful images and pretty design obscure the information they are meant to depict. A massive and intricate chart on British public spending is just visual gibberish. A circular bar chart comparing China and America places variables alongside each other that have no rapport whatsoever. In "The Infographic History of the World" James Ball, also of the Guardian, and Valentina D'Efilippo, a London-based graphic designer, created around 100 charts that span the Big Bang to modern times. The authors have put as much effort into the design as the data and their book is meant to entertain as much as to inform. There are terrific charts on the origin of musical instruments across the millennia, the duration and army size of the nine Crusades and a beautiful comparison of every British, Dutch and Spanish sea voyage between 1750 and 1800, displaying clearly how Britannia really did rule the waves. In tracing time, the authors cleverly change the typography and even paper stock from primitive to modern. However, they lose sight of the ultimate purpose, which is to convey information. In a graphic on marriage and divorce they used a bar chart with spindly points - points so fine that it is almost impossible to see the actual "story" in the data: the number of marriages have about halved in many countries between 1970 and 2009. Though the book is a delight, too often the authors lack the infographical discipline that Mr Yau calls for in "Data Points." But should these books have been published on paper at all? Today's most impressive works, like "Wind Map," were created to be online. Future infographics will be digital, data will stream in real-time and viewers" interactions will determine what is presented. When this happens, what constitutes a good infographic will change. The revolution has just begun.