Thursday, August 11, 2011

Blog Holiday

Today's was the last post until September - I'm taking some holiday and I also need to focus on some other projects.  Do check back after August is over as I have something exciting in development to announce.

Navigation - Too much freedom?

I'm currently writing a paper about the use of GEarth Tours in education.  I thought I'd discuss one aspect that's come up: the problems of navigation in 3D software (thats Maps as well as GEarth as you effectively move through 3D space using pan and zoom).

The Problem: In GEarth you have 5 degrees of freedom:
  Altitude, Latitude, Longitude, Camera Pitch, Camera direction
Controlling these is complex and so causes problems - users can:
  • become lost in virtual space
  • get disorientated 
  • become confused as they fly through model walls (ie inside a building only designed to be seen from outside)
  • navigate around missing the views that the designer of a GEarth project wanted them to see.
As you may imagine any combination of these leads to the same result:  users become disheartened and leave to go and look at something else.

Similar Problems in other Software:  It isn't just GEarth - map systems, information spaces with pan and zoom functionality and Virtual Worlds all suffer from similar problems.  In some software its possible to fly straight into the ground with nothing visible at all which is when you get 'desert fog', users don't know where they are with no visual clues on screen to help them.

Solutions:  There are multiple solutions I've found in the literature, one is illustrated by Google Body:  Constraining freedoms of movement from 5 to 2.  When viewing the body your camera angle is fixed and you can only fly around a cylinder of fixed distance from the body (in fact it feels more like you are moving the body rather than your camear position but actually they add up to the same thing).  

GEarth Tours:  The solution readily available in GEarth is the GEarth tour, effectively you are constraining the user to 1 degree of freedom as within a tour they only have the ability to play or rewind  - nothing else.  This means that providing the tour is designed well we mitigate or solve all the problems I listed above.  

In education removing those issues comes at a cost:  users watching a tour are far more passive than if they are navigating around so we have to be careful to insert active tasks into tour.  For example, turning the tour off for a while and having students go and search for a landscape linked to the GEarth tour they've just viewed.  How to do this is the theory that we are investigating with our Google Research Award.

Thursday, August 4, 2011

Usability testing and Problems with Questionnaires

I came across this interesting presentation from Patrick Weber and Catherine Jones (amended to name both authors 11 August) at SOTM eu. He discusses usability issues with Open Street Maps editor using eye tracking and usability techniques. I only got the video to work by downloading it, the player didn't work.

Map Usability: What's great about this is that its a discussion about the usability of maps in the public sphere not a secret report for some company. IMHO there is a great need for much more of this work, we're woefully unaware of how to make interactive maps usable. It has lots in common with a current MSc project I'm supervising that I discussed last week looking at placemark clustering.

Simple Testing: Patrick discusses results from videoing users and eye tracking. These tools definitely help analyse and communicate the issues that arise from testing but you can still find out a lot without these tools via a technique is called Hallway testing (talk aloud procedure). It takes about half a day and needs no eye tracking or video recording.

Testing 'Doing' not Gathering Opinions: Hallway testing is pretty quick given the amount of information you get from them but its quicker still to gather feedback by questionnaires. Questionnaire feedback gives you some useful insights into your map system but it is by no way a complete picture. This was bought home to me this week in a reference I found about users searching for targets in overview* maps. The experiment tested search tasks with and without an overview map. Users were very positive about the value of overview maps but when the speed and accuracy of the searching were analysed using the overview it turned out that their performance didn't improve. Questionnaire data can be misleading, to really find out the truth you have to observe (and measure if you can) users trying to complete tasks with you map based tool.

*An overview is a small map in the corner of a web page showing the view from a higher altitude and usually marking the current view.

Monday, August 1, 2011

Where's Latitude 41 gone?

I notice that a great source of neo-cartographic discussion,, is now blank with no goodbye message. Anyone know what's happened? I have an idea but if anyone's got any firm news I'd be interested to hear.