Friday 19 November 2010

Do we really need maps for analysis?

This is a response to Barry's QlikFix post -

While interesting that 80% of data may have a spatial component (depending on how you define it), the reality is that the majority of that data does not have a special dependency – it is not really that suitable for display on a map.

A common example for such displays might be something like sales by state. These are often displayed as bubbles geographically positioned over the state in question but do they really help with the analysis? Sure, you may be able to easily see that sales in California are larger than in Oregan, but how do they compare against sales in New York, New Jersey and Rhode Island that may be smudged together on the far side of the map. What might look “cool” on a demo may turn out to be something that is easier to analyse in a bar chart.

One other unfortunate flaw is the level of education that might be encountered. Studies have shown that percentages of schoolchildren in the UK have difficulty picking out their own country versus France or Germany! Can we expect that everyone who needs to analyse European data is actually aware that the boot shaped country is Italy?

Maps can be cool and have some great applications (many of which can be easily done in just Google maps without QlikView). Real world analysis can mostly do without them.


  1. Stephen,

    I think you are both right... I don't think it's a case of either / or.

    I work in the field of supply chain and I agree that so far we managed to do our analysis without the need for maps.

    Still, I think it's worth trying and see what maps can bring to analysis. Even if that's just a "cool" feature.

    I have noticed that many people struggle in handling data/graphs, but they are somehow attracted to maps and other funny visualisations.

    I don't know if that will help spreading a more analytical culture in organisations, but I think it's worth a shot. If that's what it takes to get the message across, why not...



  2. I agree, but I also think that maps allow us to see trends better than sorted numbers. For example, if California, Nevada, Washington and Arizona all have lower sales, the place relationship would be more visible on a map, and that will also show maybe a trend with surrounding states.

  3. Hi Marco,

    I am interested in how you might display a trend on a map?

    Spark lines? Might be mistaken for rivers ;-)


  4. Stephen,

    While I agree that not all data is suitable for display on a map, I do not agree that analysis can mostly do without maps.

    The sales by state example that you mention might be better visualized in a bar chart, though I can imagine that a bar chart with 50 bars might not exactly be easy to interpret either.

    That being said, there are many examples where displaying the data geographically does add new insights. Take for example this map depicting unemployment rates in Belgium:

    Looking at this map immediately shows you that the unemployment figures are very different on the Flemish and French speaking sides of the language divide. This sort of insight cannot be easily gleaned by looking at a bar chart or static table.

    Regarding your point about education, of course when designing a dashboard/report it is very important to keep your end-users and their level of knowledge in mind. The Belgian unemployment map only works if the end-users know where the divide is.

    When I design a solution, I always work very closely with the end-users to make sure the information is displayed in a manner that they understand and are comfortable with. In the end it is not about showing off your cool visualization skills, it is about delivering a solution that the end user can comfortably work with and derive value and insights from.

    I do not agree that maps should be kept outside of QlikView. The power of QlikView (and similar tools) is that it can display the same data from many different angles at the same time, letting you interact with the data and discover new relationships between the various dimensions. In trying to figure out the “why” and “how” of our data in QlikView, we are already visualizing the “what” (facts) and the “when” (time), so why not the “where”?

    Kind regards,


  5. Barry,

    Does that map of Belgium really give more insight? I could as easily make the same point with a 2 bar chart! Also, as a non-Belgian, I need to know Belgian geography and demographics to interpret it. You could show the 2 bar chart to anyone in the world and they could see that unemployment is greater in the Waloon areas versus the Flemish areas. Of course, what it (or my bar chart) doesn't show is the fact that the higher population is in the larger cities in the north (population is 2:1 between the 2 areas). Does it show me that the south is more agrarian and that young people migrate to the French speaking cities of Bruxelles, Charleroi or Liege (or even to French cities) where, being unskilled, they swell the unemployment figures there; whereas the more industrial north has more jobs for their Flemish speakers (all of which is pure speculation on my behalf because I don't have the data - and the map doesn't tell me this at all).

    I am fully supportive of giving people as much information as possible from different locations. But give it to them simply where it can be easy to interrogate and drill around. A map is just one view of things. There are much better, and simpler, ways of doing it.



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