For my book review this week I decided to do it on “Golden Rules for Great Business Charts” by Laszlo Zsom, an essential read for anyone starting in the world of data visualisation. The preface of the book is to give the readers a top level guide into data visualisation best practice. Rather than providing specific software based tutorials or lengthy blurb about certain concepts, the book aims to condense the expertise of the author into “golden rules” that all data visualisers should follow.
There are 50 golden rules and each is based on a different area of chart best practice, the author states that these cover “at least 90% of the potential business aspects”. All the examples are based on sample data and designed to show the methodology of the rule rather than showing a specific data insight.
The rules are laid out in such a way that each is given at least one example of a good chart (following the rules) and at least one bad example of a chart. The text for each rule is short and concise, however I found the layout of some pages confusing as some charts that were referenced in the text were not visible until you turned the page which made referencing a challenge.
To outline some of the rules that the author has laid out I will demonstrate the “golden rules” in practice:
Rule 24: Standard, consistent colour codes
Rule 24 describes the need for consistent colours across charts that are showing data for the same subset. Take the chart below as an example of bad practice, The colours of each region have changed when moving from the line chart to the stacked bar chart. These means if the reader has learnt the colours for each region on the line chart, they then have to forget those and re-learn the colours when looking at the second chart.
An example of good practice is below, these charts share the same colour legend and therefore the reader will find it easier to scan between the two charts once they have learnt the region specific colours.
Rule 33: Highlight the important or outstanding data values
This rule describes the need to emphasise key talking points when it comes to data visualisation. The image below shows both bad practice and good practice. The graph on the left shows “sales” for a 14 year period however it is hard to really distinguish any clear patterns or outliers from the bars as they are all relativity close together. The second chart, on the right, instead takes these values and calculates when sales have increased or decreased on the previous year and highlights these values with a clear colour code. Also labelling the biggest changes for each side of the axis.
In conclusion I have enjoyed reading this book, it has made me think twice about the way to best lay out charts and given me some interesting techniques to use moving forwards. The layout is not the greatest and the cover is certainly not the most inspiring but the actual contents of this book are of vital importance for anyone looking to improve their business charts.