Wednesday, May 12, 2010

Google Earth Tours in Geog. Teaching I

This post is the first of three posts on the topic, I offer practical advice on how to use tours in geography teaching with links to specific tutorials where necessary. In today's post I will cover some best practices achievable with with simple tours.

Tours in Education: A tour is a pre-recorded virtual flight around a virtual globe (see example above) and has two strong applications in geography education: A teacher can use them in place of a PowerPoint presentation for part or all of a lesson and students can be set assignments or tasks that involve them producing their own tours.

Why Google Earth Tours? At the time of writing 'tours' are available in two virtual globes, Arc GIS Explorer (AGX) and Google Earth. In some ways AGX offers a richer way to create tours, for example slides from a PowerPoint presentation can be easily incorporated into the tour. However, Google Earth is arguably the better virtual globe and also has a tour audio feature which AGX lacks.

Best Practices: Many best practices in using GETs are the same as best practices for producing maps in Google Earth, for example, good icon design. In the following discussion we refer to best practices that apply mainly to producing GETs. They are arranged in rough order of complexity with the easiest to implement listed first.

1. Scale, Location and GETs A GET is best applied when displaying changes of scale and location. The above example shows an overview of the ships route before zooming in on the ship itself to add detail. If changes of scale and location are not important your narrative it is quicker and just as effective to use presentation software such as PowerPoint.

2. Rules of Thumb for GET Flights These section 2 best practices are part of a group about how to best move the camera viewpoint within a GET.

a] Looped Flight: It is possible to fly from location to location in a way that confuses the user. For example, if we were to position the user over a house in the UK and then fly them rapidly to a house in South Africa at a low altitude the user may fail to realise which country they have ended up in. If the flight path follows a looped path pausing at high altitude with both houses in view, the user has the opportunity to see that they have flown South over the Mediterranean before descending to South Africa.

To force the GET to fly high between two low points of interest simply fly to an appropriate high altitude camera position and insert an intermediate placemark, use of placemarks to control camera locations is explained here.

b] Think about speed: If a flight is too rapid the user might fail to realise where they have travelled to but if it's too slow you may lose their attention. This point is related to point [a] because if you keep visual cues in view the user can follow a quicker flight. This topic needs further research but for now, testing a tour out on a likely user is an effective way of assessing if you have the speed correct.

To be continued.

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