Saturday, March 19, 2016

Tracking students in Google Earth

Our paper 'Footprints in the sky: using student track logs from a 'bird's eye view' virtual field trip to enhance learning' has been published.  It describes how students were tracked zooming and panning around Google Earth on a virtual field trip.  Their movements were recorded and their visual attention inferred as a paint spray map: high attention = hot colors, track = blue line.

A paint spray map of 7 students (1-7) performing a search task in Google Earth.
Background imagery has been removed to aid clarity.
Click to expand.

How it works
The idea is to track students performing a search task, in our experiment they looked for evidence of an ancient lake that has now dried up in a study area.  Their 3D track as they zoom and pan around in Google Earth is recorded, their visual attention is mapped as if it is a can of paint spraying:  if they zoom in to check an area in close up, Visual Attention (VA) builds up, if they zoom out VA still builds up but is spread over a much larger area.

Mapping the accumulation of VA  along with their track projected onto the ground (blue line) shows where the students have searched and in what detail at a glance.  The small multiples above show data from 7 students who were given 3 set areas to investigate in further detail (target/guide polygons).  This was done in Google Earth but to aid visability, the Google Earth base map has been removed.  From the maps we can predict what the students were doing, e.g. student g5 didn't appear to visit the top right guide polygon at all and students g1, g3 and g6 only gave it a cursory look.  By comparison, students g2 and g4 explored it much more thoroughly.

How it could be used
The idea would be to give the maps to students to help them assess how they did on the exercise.  In addition the VA from all students can be collated which can be used by the tutor to see if his/her activity worked well or not (bottom right of the multiples above).  In this case the summed VA shows that students examined the areas they were supposed, that is, within the target/guide polygons.

The system only works with a zoom and pan navigation system where the zoom function is needed to explore properly.  If the exercise can be solved just by panning, a paint spray map won't show much variation in VA and interpretation would be difficult to impossible.

Other Related Work
Learning Analytics is a growing area of investigation, there's lots of work tracking student's logs using VLEs (LMS in US) to understand their learning.  There has also been use of tracking to see where avatars have moved in virtual environments, visualizing it as a 'residence time' map similar to the VA maps above.  However, this is the first attempt we've come across where movement in 3D virtual environment via zoom and pan has been tracked and visualized.

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