Thursday, October 20, 2016

New Paper: How to make an Excellent Google Earth tour

We (myself and Artemis Skarlatidou) have just submitted a paper to a cartographic journal about a successful experiment we did on users' understanding of Google Earth Tours.  The work produced two rules of thumb to consider when making Google Earth tours so I thought I'd blog about it.  Note that the title of this post isn't how to make a 'cool' Google Earth tour that grabs users' attention, this is about how to use them as an effective communication tool.

Why should I care about Google Earth tours?
Before we get to the two best practices its useful to think about the media we're discussing.  Is it worth using?  My answer to that is that Google Earth tours are common on the web and the wider generic group of Google Earth like animations (Atlas tours) are everywhere!  e.g.:
- TV (e.g. weather forecasts)
- The web (e.g. National Geographic)
- Mobile satnav apps

As an example of Atlas tours in satnav apps, both Google Maps and Apple Maps in driving directions mode will zoom into tricky road junctions when you approach them but then zoom out when you are on a straight road section to show you the wider view.  

So you should consider creating a Google Earth tour (or Atlas tour if you prefer) as a way to tell your spatial story.

Best practice 1: use high paths
If you are producing a tour with two or more low points, you get to choose how the camera moves between the two low views.  Users' mental map of the study area will be better when your tour following a 'Rocket' path(1) where there is a mid point where you can see the start and end of your tour. This video explains the point and tells you how to achieve it technically in Google Earth:

Best practice 2: use of speed
We haven't explicitly proved it but an animation speed of 1 second for any camera motion is a good rule of thumb(2).  If the tour is more visually complex, you may want to slow the speed down.  Reasons to take more time:
- You are flying through a complex 3D cityscape
- There are lots of elements on screen (points, lines, areas) that you want users to understand

As an example, these are some of the experimental Google Earth tours; only the 'low, fast' condition really troubled the users in the experiment.

Atlas tours are very common as they are an effective media to communicate a spatial story or data.  Google Earth is one of a suite of software that can be used to produce Atlas tours, I think the principles described here will apply whatever software is used.

I read all the studies I could find in 2011 and produced an earlier paper which discussed these and 17 other best practices for producing Google Earth tours.  This is the shorter blog version of the paper.

1] In the paper, this is called the high path.  Less memorable but more professional sounding.

2] our experiment ran at speeds slower than this and user's had little problem building up a mental map of the study area.