AGI GeoCommunity ’08 – some reflections

The AGI GeoCommunity ’08 is over – and it was a great conference. Building on the success of last year, the conference this year was packed with good papers and with 600 delegates. I found the papers from Joanna Cook, of Oxford Archaeology, about the use of Open Source GIS as the main set of products in a business environment, and from Nick Black, of CloudMade, on Crowd Sourced Geographical Information especially interesting.

What is especially good about the AGI in general, and the conference in particular, is that unlike other forums that cater for a narrow audience (say mainly neogeographers in Where 2.0, or academics in GISRUK), the AGI is a good forum where you can see vendors, commercial providers, veterans and new users all coming together to talk about different aspects of GI. Even if they disagree about various issues such as what is important, having the forum for the debate is what makes this conference so valuable Just look at the blogs of Ed, Adena, Joanna, Andy and Steven for such a debate to see that there are issues that people will argue about quite fiercely – which is a sign of a great conference.

I’m especially pleased with the success this year of bringing in people from the academic community who presented papers and attended the conference. This interaction is very significant as, through our teaching programmes, we are actually training the people who will join this crowd in the future, and we should keep an eye on the trends and needs of the sector.

For example, one of my conclusions from the conference is that the existing ‘business model’ of the M.Sc. in GIS programmes, which was, inherently, ‘we’ll train you in using [ArcGIS|Mapinfo|other package] so you can get a job’, is over. The industry is diverging, and the needs are changing. Being a GI professional is not about operating a GIS package.

We should now highlight the principles of manipulating geographical information, and, as Adena Schutzberg commented during the debate, train people how to ask the right questions, and to answer the most important ‘So what?’ question about the analyses that they are producing.

We should also encourage our students to participate in forums, like the AGI, so they continue to learn about their changing world.


OpenStreetMap Quality evalution and other comparisons

A comparison of my analysis of OpenStreetMap (OSM) quality evaluation to other examples of quality evaluation brings up some core issues about the nature of the new GeoWeb and the use of traditional sources. The examples that I’m referring to are from Etienne Cherdlu’s SOTM 2007 ‘OSM and the art of bicycle maintenance’, Dair Grant’s comparison of OSM to Google Maps and reality, Ed Johnson’s analysis this summer and Steven Feldman’s brief evaluation in Highgate.

Meridian 2 and OSM in the area of Highgate, North London
Meridian 2 and OSM in the area of Highgate, North London

The first observation is of the importance and abundance of well georeferenced, vector-derived public mapping sites, which make several of these comparisons possible (Chedlu, Dair and Feldman). The previous generation of stylised street maps is not readily available for a comparison. In addition to the availability, the ease with which they can be mashed-up is also a significant enabling factor. Without this comparable geographical information, the evaluation would be much more difficult.

Secondly, when a public mapping website was used, it was Google Maps. If Microsoft’s Virtual Earth had also been used, it would arguably allow a three-way comparison as the Microsoft site uses Navteq information, while Google uses TeleAtlas information. Using Ordnance Survey (OS) OpenSpace for comparison is also a natural candidate. Was this familiarity that led to the selection of Google Maps? Or is it because the method of comparison is visual inspection, so adding a third source makes it more difficult? Notice that Google has the cachet of being a correct depiction of reality, which Etienne, Dair and Bob Barr demonstrated not to be the case!

Thirdly, and most significantly, only when vector data was used – in our comparison and in parts of what Ed Johnson has done – a comprehensive analysis of large areas became possible. This shows the important aspect of the role of formats in the GeoWeb – raster is fabulous for the delivery of cartographic representations, but it is a vector that is suitable for analytical and computational analysis. Only OSM allows the user easy download of vector data – no other mass provider of public mapping does.

Finally, there is the issue of access to information, tools and knowledge. As a team that works at a leading research university (UCL), I and the people who worked with me got easy access to detailed vector datasets and the OS 1:10,000 raster. We also have at our disposal multiple GIS packages, so we can use whichever one performs the task with the least effort. The other comparisons had to rely on publically available datasets and software. In such unequal conditions, it is not surprising that I will argue that the comparison that we carried out is more robust and consistent. The issue that is coming up here is the balance between amateurs and experts, which is quite central to Web 2.0 in general. Should my analysis be more trusted than those of Dair’s or Etienne’s, both of whom who are very active in OSM? Does Steven’s familiarity with Highgate, which is greater than mine, make him more of an expert in that area than my consistent application of analysis?

I think that the answer is not clear cut; academic knowledge entails the consistent scrutiny of the data, and I do have the access and the training to conduct a very detailed geographical information quality assessment. In addition, my first job in 1988 was in geographical data collection and GIS development, so I also have professional knowledge in this area. Yet, local knowledge is just as valuable in a specific area and is much better than a mechanical, automatic evaluation. So what is happening is an exchange of knowledge, methods and experiences between the two sides in which both, I hope, can benefit.

The new London crime mapping website

The Metropolitan Police Authority has released a beta version of their new Crime Mapping application, showing the generalised level of crime (burglary, robbery and vehicle) for Lower-level Super Output Areas (LSOAs). The application uses generalised boundaries of LSOAs , and use a clear classification of the level of crime. Interestingly, the Show Us a Better Way website includes several suggestions for crime mapping – so there is an ongoing public interest.

This is not surprising, based on my own experience with CamStats, which was developed in collaboration between me, Kate Jones and Dave Ashby for Camden Police in late 2003, with the website operating from early 2004 until late 2007.

As you can see from the slideshow above, the information that CamStats provided is richer than what is available today. CamStats was based on static maps, and was very easy to produce – we designed it so a team administrator (with no GIS skills) could compile monthly and annual statistics simply by copying a data file to a processing machine, and then clicking one button in Mapinfo Professional which called Mapbasic, Perl scripts and other utilities to create, process and map the data and compile the HTML pages for the website into one zip file. All the user had to do was transfer the zip file to the Met web team who easily updated the webserver by unzipping the files. The fact that it was running for three years without any request for support is something that Kate and I are justifiably proud of.

Notice that CamStats provided options to see different geographical units, different forms of visualisation and to view the information in tabular and chart forms. Users could even download the aggregate counts for each area to compile there own reports. This was particularly useful for a number of community groups in Camden.

There is no question that the use of Google Maps, which provide context for the statistics is a huge usability improvement over our implementation. However, it will be interesting to see how long it will take the Met team to reach the functionality and ease of use CamStats provided …

Mapping Change for Sustainable Communities – videos

The UrbanBuzz team that recorded some of the community showcase presentations during the Mapping Change for Sustainable Communities event in June, have now released the videos on YouTube. The videos are showing the posters and explanations for our work in Marks Gate, Pepys Estate and Hackney Wick. The presentations are by members of the communities, with some help from the project team.

This is the video for Marks Gate, where the focus was on community perceptions about their environment and how it can improved:

The next one shows the noise mapping work in the Pepys Estate (and I had the pleasure of assisting Caroline to explain the mapping):

And the final one shows the historical mapping in Hackney Wick:

The three videos give a good overview of the community mapping projects that were carried out within Mapping Change for Sustainable Communities, and the Environmental Justice projects with London 21 and London Sustainability Exchange .

What’s in your back yard? – the latest edition

The Environment Agency has released the new version of their ‘What’s In Your Back Yard?’ application, which allows you to find out about pollution incidents, water quality, and flood risk in your area. Similar to the rest of the website, it is still designed for 800×600 screen resolution, although not really – the legend spills to the bottom and requires scrolling down.

The application takes a lot of the new interaction metaphors that we’ve become accustomed to in Web Mapping 2.0 – slippy maps that can be panned easily, obtaining information by point and click on the map – unlike the cumbersome way in which it was handled in the previous version. There are also other improvements such as more data.

Yet, there remain some of the most common mistakes that I have pointed to in the past – the maps are still small and too generalised to really see what is in your area, they still have the weird scale statement at the top of the map (what does it means that the scale is 1:650,000?).

Also, notice that the slippy map implementation is such that, after you move the map, it disappears and then reappears – it takes about 3 seconds which is enough to make it difficult to relocate yourself on the map. That’s actually not a good implementation – the whole point of slippy maps is that only a small area of the screen is being refreshed, making it easy for users to keep the image in their short-term memory.
The last aspect that I would expect in such an application released in 2008 is the ability to download the data from the application (see the Power of Information report) or to have a well-controlled API as in OS OpenSpace.

So, it’s a move in the right direction, but a long way to go …

OSM quality evaluation

In the past year I have worked on the evaluation of OpenStreetMap data. I was helped by Patrick Weber, Claire Ellul, and especially Naureen Zulfiqar who carried out part of the analysis of motorways. The OSM data was compared against Ordnance Survey Meridian 2 and the 1:10,000 raster as they have enough similarity to justify a comparison. Now, as the fourth birthday of OSM is approaching, it is good time to evaluate what was achieved. The analysis shows that, where OSM was collected by several users and benefited from some quality assurance, the quality of the data is comparable and can be fit for many applications. The positional accuracy is about 6 metres, which is expected for the data collection methods that are used in OSM. The comparison of motorways shows about 80% overlap between OSM and OS – but more research is required. The challenges are the many areas that are not covered – currently, OSM has good coverage for only 25% of the land area of England. In addition, in areas that are covered well, quality assurance procedures should be considered – and I’m sure that the OSM crowd will find great ways to make these procedures fun. OSM also doesn’t covered areas at the bottom of the deprivation scale as well as it covers areas that are wealthier. The map below shows the quality of coverage of the two datasets for England, with blue marking areas where OSM coverage is good and red where it is poor.

Difference between OSM and OS Meridian for England
Difference between OSM and OS Meridian for England

The full report is available here, and if someone is willing to sponsor further analysis – please get in touch!

The paper itself have been published – Haklay M, 2010, “How good is volunteered geographical information? A comparative study of OpenStreetMap and Ordnance Survey datasets” Environment and Planning B: Planning and Design 37(4) 682 – 703

Are SatNavs dangerous?

The Daily Mirror recently put out a summer story on the risks of using SatNavs. While I would question the statistics and the reliability of the information, as it is probably based on a quick phone survey of 2000 people and then extrapolated in some unclear manner, I do think that we need to understand more about the tunnel vision that SatNav devices create in user’s mind.

The problem of showing a users only small section of reality without the full context is surely the right way to provide information in a short burst that does not risk them too much. While I still want to see some research on how long do users look at their SatNavs using an eye tracker (if anyone is willing to sponsor this – we’ve got the equipment!), I’m confident that there is solid reasoning behind the visualisation as it is now.

So, although this is suitable visualisation, we have an unintended consequence of tunnel vision view of the environment through which the user navigates. We are now starting to see some of the misshapes that occur due to this, and that is an area that requires more research and understanding.

See also the comments in the recent Interactions by Elisabeth Churchill about SatNav