Thursday, November 8, 2007

Tufte ideas on Google Earth Projects

A lot of work time is going on interesting project bids and teaching duties at the moment hence the lack of posts. All the projects involve Google Earth in some way so I may post some details in the future.

For now I wanted to review a post by John Krygier on 'how useful is Tufte for making maps'. Edward Tufte is a major influence of mine so its interesting hearing what John has to say and then comparing his ideas about static maps to my own on how Tufte can be applied to Virtual Globes.

John starts out by stating 20 Tuftesque rules from one of Tufte's text books, his points 14, 15 and 16 (Maximize data-ink ratio, Erase non-data ink and Erase redundant data-ink) seem to be repetitions to me but never mind, there's a lot of interesting advice in the list. He then combines these into 6 map making commandments, I'll comment on 3 of these today with relation to map making in virtual globes and the rest in a later post.

Commandment 1: Map Substantial Information
As I pointed out in the launch podcast for this blog it is possible by thinking carefully about design, to layer many different types of data onto one map. This is as true for virtual globe maps as it is for paper maps, however, with Google Earth we have the ability to turn different data on and off. I think this leads to a lot of sloppiness amongst those building Google Earth projects, the impact of what data layers look like to when combined is not always considered. My post on folders as picture frames expands this point, having to turn layers on and off adds complexity to a user's experience. It's better if we design layers to look clear when combined.

Commandment 2: Don’t Lie with Maps
I have to say that with all the Google Earth projects I've looked at I've never thought so far that someone is trying to mislead me. However, it is entirely possible to present the data in a way that misleads in a virtual globe. For example, by reducing the size of the oil well icon in the Sierra Club project on the Artic the interpretation is that the oil wells are less of a problem even thought the data is exactly the same:

normal sized icons

Reduced size icons representing oil wells

Commandment 3: Effectively Label Maps
Most project designers in Google Earth rely on keys and on balloon information to explain data. I have seen someone label the timeline to try and help users control it correctly via a screen overlay but otherwise I haven't seen anyone adding labels in an overlay image. I think it could be a good design practice.

Commandments 4 to 6 in the next post.

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