As I’ve noted, the AGI GeoCommunity ’08 was a great conference, but it was especially pleasing to end up with the paper that I wrote with Kate Jones being selected as runner-up for the best paper competition by the conference team (and I kept myself at arms length from the judging!). Maybe it is a sign that the message about the importance of usability and interaction is starting to gain traction within the GIS community, though I should also note that Clare Davies from the OS raised the issue in the AGI conference in 2005 – so it’s still one usability paper every 3 years!
While you can download the full paper from here, or look at the presentation below, the short explanation of the argument behind the large monitor is actually raising a very significant and overlooked aspect of interaction with GIS.
Inherently, the issue is that interaction with maps is all about the context. You can’t design the position of a telephone pole if you can’t see the other poles, and you can’t understand where you are in relation to a local tube station without seeing it. This is where the abysmal resolution of current computer monitors causes a problem. Because the information density (the amount of information that you can cram into a specific area, say a square inch) of a monitor is low – it’s 10 times lower than a printed map – it’s actually very rare that you can put all the information that the user needs on one screen.
This is why all GIS developers are giving too much attention to zoom and pan operations, as they are perceived as the solution to this problem. However, and this is the most important point – zoom and pan are never part of the user’s task. The user is not interested in zooming and panning for their own sake, but in manipulating the map so they can see the area that they need to perform their task (adding a pole to the map, analysing neighbourhood, etc.). In an ideal world, the GIS will ‘know’ what area the user is looking for and will show it so there is no need to manipulate the map. However, we don’t have this so we must use zoom and pan…
Here is where the productivity issue kicks in. An average zoom or pan operation in a GIS application can take up to 30 seconds. Over a working month, this can accumulate into many hours for a heavy user of a GIS. A larger monitor (24 inch or even 32 inch) will reduce the number of zoom and pan operations, and thus increase the productivity of the user. Considering that a GIS analyst’s minute is costing about £0.30 (a conservative estimation), the large monitor will return the investment within 2 months.
But even more important is the issue of GIS interface design – this analysis emphasises why the decision on how much screen assets are dedicated to the map should take into account the user’s task, and not assume that they’ll zoom and pan!