The slides are here: (pdf).
Information Design
Caroline Robinson FRGS, an experienced designer and cartographer, introduced some of the principles for designing effective information visualisations.She focusses on two key elements - colour and typography.
Caroline explained that colour fidelity is not easy to ensure, one person's display and printer will not necessarily output the same colours as those on another's. In fact, colour accuracy and reproducibility is a very broad and deep area.
She explained that, in the past when many displays only supported 256 colours, an informal standard of so-called web-safe colours emerged. Today, this is less of a challenge, but where high assurance is required, the industry standard is the Pantone colour scheme. By referring to named colours, different people, organisations and technologies can be assured they mean the same colour as printed in reference swatches, like this one which Caroline which brought in to show the group.
Caroline also discussed the important issue of colour blindness, with about 1 in 10 people seeing colours in ways different to others. It was a surprise to me that a common colour combination, red and green, often chosen because they appear opposite, are in fact difficult for many colour blind people to distinguish.
In terms of cognitive load, Caroline recommended that chart keys or labels do not grow beyond 7 colours.
Caroline recommended that the best approach to colour design was to test with a range of users, not just for an ability to distinguish colours, but also for cultural interpretation too. For example, red in some cultures doesn't mean danger but is a sign of good luck.
On typography Caroline explained that serif fonts are easier to read, and is particularly suitable for body text. She explained that sans-serif variants are better suited to headings and titles.
She also explained that the size and clarity of the "round circles", shown above, are key in aiding the readability of text.
Using examples and props, Caroline got us to think about the human side of design - how some people can or can't see colours, how design choices can have different cultural significance, and also the broader challenge of bias in the data use.
Geospatial Information and Maps
For the second part of the evening, Caroline led us through a hands-on introduction to maps and geospatial data using QGIS, a leading GIS tool which also happens to be open source.
One of the great developments over the last few years is the open source maps and map data. Open Street Map is a leading example of collaborative contributions together building a free to use map of the world. Proprietary alternatives are either expensive or have constrained terms of use.
The following shows the QGIS using OpenStreetMap to show the Penryn campus where we were meeting.
Caroline stressed several times the importance of making sure the right projection is used when using maps, and especially when combining multiple maps or data with maps. If this isn't done right, features will be placed at the wrong location.
The root of this complexity is that the earth is a sphere and most maps are flat surfaces, and there are many choices for how the earth's surface is projected onto flat maps. Some projections aim to preserve distance from a given point, others aim to preserve area, for example.
The first exercise was to add points to our map. The following dialog shows these such points have a rich set of metadata, and also options for user-defined data.
The following shows a set of points added to map, shown as red dots.
These dots, which could represent trees for example, can be saved to a file. The format, called a shape file, is industry standard, open and interchangeable. These are essential characteristics for using data across different systems and organisations, and simplifies working with them programmatically.
The shape files can also include metadata for ownership and copyright information too.
In addition to points, we can add lines and polygons. The following shows an open poly-line (fence) and a closed polygon (building).
The map shows how different shapes can have different colours, but also display attribute table data. In this case the numbers inside the polygons could refer to the building capacity.
Caroline also demonstrated the various options for importing and exporting map data.
To reiterate the importance of selecting the correct projection, the following shows a common map of the world, with Japan and Britain highlighted. They look comparable in size.
In the next map, Japan has been moved closer to the Britain, preserving its area. It is clear that Japan is much larger than Britain, which wasn't apparent on the previous map.
In the next map, Japan has been moved closer to the Britain, preserving its area. It is clear that Japan is much larger than Britain, which wasn't apparent on the previous map.
Thoughts
For me the field of geographical information systems and working with maps has become democratised through open source tools, maps and data.The importance of this can't be understated. The cost of the proprietary ArcGIS tool is beyond the reach of most individuals and organisations, and historically, maps and location data came with heavy licensing terms and costs.
Today, thanks to open source tools, maps and entity data, we have a rich and vibrant ecosystem of products, innovation and educational possibilities.
