Po Ve Sham - Muki Haklay’s personal blog

This week, we have released the ‘Suburban Town Centres Profiler’. The application can be accessed from the Towards Successful Suburban Town Centres website, and was originally developed to support hypotheses development within the project’s team. It’s been quite a while that we’ve been working on the range of maps and information the profiler is based on, practically since last summer.

All the details about the profiler are on its website, but an interesting point that underpins it is that, in some cases, it is worth sacrificing the interactivity of the map itself to allow users to concentrate on the information. In HCI terminology, the main task is not about interaction with the map but with the information and its meaning, so providing interactive maps will actually reduce the usability of the application!

The maps on the profiler do not support zoom in, zoom out or panning. However, they are not meant to be interactive by themselves. The idea behind the application is to allow systematic and consistent comparison of many layers of geographic information across a range of 26 town centres in London’s suburbs. To achieve this task, the interface allows us to switch between themes and explore various datasets quickly, and, by ‘locking’ the map itself, we can ensure that we are looking at each Town Centre at the same scale and to the same extent. I’m sure that there are other cases where such an approach is the correct one – not all interactions are necessarily helpful to the user’s task…

MySociety’s FixMySteet is somewhat similar – it is holding the scale constant while allowing Panning.

The Manifold training course that we ran earlier in February is always an excellent opportunity to observe how new GIS users interact with such a system.

Running a training session for new users of any GIS will expose major usability problems with the interface. Many of these problems are unnoticeable to experienced users, since they have learned the idiosyncratic aspects of the interface. Usability problems surface in such a session through misunderstandings and questions that the participants raise.

With Manifold, one of the interesting problems that came up is with the query toolbar (see below):

The way the query toolbar works is that you select a field in the left drop-down list, an operator at the central drop-down and a value in the text box on the right and click on select to see the result. For example, if you enter 5 in the toolbar in the picture, it will lead to a selection of the 5 polygons on the map with the smallest area.

The confusing part of the interface is the ‘not’ between the left drop-down and the central one. For a new user, the interface reads ‘find objects on the map where the field Area (I) are not the bottom X’. The ‘not’ in this case is a toggle button that can be activated to negate the operation that was selected in the central drop-down. Clearly, it would be better if, when not activated, it had the word ‘is’ (Area is the bottom 5) and ‘not’ appeared only when it was active. This is one of the cases where usability enhancement could be carried out in less than a minute of a programmer’s time – and surely makes life less confusing to many novice users…

UCL’s licence for Manifold GIS 8.0 finally arrived. While testing the new 64-bit version I was reminded of one of the interface features of Manifold that I believe many other GIS should have as standard – a request to verify projections when a new component is added to the project.

One of the most confusing issues for new GIS users is to use projections within their workflow. Nowadays, it is common to integrate data from different sources, such as information gathered by GPS receivers with data from the Ordnance Survey, or any other data that is using a local projection. Therefore, it is important to ensure that the system ‘knows’ what the projection of each layer and image is.

Without proper configuration when trying to put all the data together, it doesn’t work because the projection of one layer doesn’t match another layer.

In Manifold GIS, when an image or vector layer is imported, when it is opened for the first time, the system asks the user to verify the projection, and opens the interface that allows the assignment of the current projection. Unfortunately, Manifold GIS does not give the option to set the most common the default projection for the locale in which the system is used – or at least set a group of favourite projections. Room for improvement there!

As for Manifold GIS 64 bit – it seems to work faster, although it was a surprise to see that in some operations the 4 cores were not busy at 100% or even 50% even though the system loads the data slowly. Apart from that, Windows Vista 64 bit is quite incompatible with many legacy applications and it is quite a pain to use. Maybe it’s time to return to Windows XP…

One of the questions that might arise from a look at my publications and work is ‘how public access to environmental information links to GIS, and what are the reasons to explore usability and HCI in this context?’

The answer is straightforward – there are strong links between all 3 areas and, in order to make sense of one of them, you need the others. In my 2001 paper ‘Public access to environmental information: past, present and future’ I go into more details , but here is my current summary of the issue.

One of the core concepts of environmental decision making is the use of information. In current environmental debates you can see how much opponents dispute the accuracy and validity of information, but rarely dispute the need for information or the role of information in decision making. This approach to information in decision making can be traced back more than 40 years, and has been a constant feature of environmental politics.

The next element in the chain is Geographical Technologies – GIS, Remote Sensing, ground-based monitoring and the like. One of the features of environmental information is the heavy reliance on these technologies that, historically, the environmental field adopted early on. For example, consider the following (rephrased) paragraph:

‘Existing technology now makes possible the development of a global resource data base (GRID), which will be a data management service designed to convert environmental data into information usable by decision makers. The technical feasibility of GRID has been assessed by expert groups.

‘GRID technology allows us initially to describe, eventually to understand and ultimately to predict and manage the environment.’

This is not a description of Digital Earth or from a specification document of Google Earth – it is based on UN Environmental Programme documents from 1985 and 1986, when the GRID system was in its first stages. Even today we don’t have anything like the system that is outlined above. Was it a visionary view of the potential of GIS or yet another example of technophilia? In any case, it shows the strong link between GIS and environmental information.

The next element is usability and Human-Computer Interaction. GIS are hard to use (more about this in other posts) and the reliance on them to deliver information creates real obstacles for occasional users – which most users are. I have observed the difficulties of intelligent and competent people during workshops where they were faced with the task of using GIS or web mapping technologies. That’s where my interest in this area emerged.

In summary, the challenge of providing environmental information to the public is not just the technical one of making it available over the Internet – without understanding how to make GIS more accessible for the average user and understanding which are the most efficient, effective and enjoyable ways of helping people to use the information effectively, we can’t really deliver on the promises of the Aarhus convention on public access to information, participation and justice.