The location of information sources is useful information itself. Where information is published can be valuable in many ways. Hyperlocal news services are one example. They benefit from the ability to aggregate news information based on the source of that news.

Another interesting application is in mapping source information about a particular subject. I came across an interesting blog post from InSTEDD (Innovative Support to Emergencies Diseases and Disasters). Their recent blog post illustrates the value of mapping source information on a map.  In the post they show recent information tagged with ‘influenza’ by location.  They have then overlain a representation of  the data using what is called a heat map.

It should be clear that in this particular example the InSTEDD results are not necessarily pointing to events of influenza itself but they do show patterns of information dissemination that tell their own story for those knowledgeable in this field.  Depending on the nature of the source posts, the mapped results could provide useful information about the underlying issue or simply provide insight into the patterns around the actual post sources themselves.   In either case, map representation can aid in the interpretation of the results.

One of the underlying requirements for mapping data is the need to somehow attach a location to data – in this case the location of sources who published information about influenza.  This location information has to be in a form that will allow an association with a point or region in order for it to be represented on a map.   The technical term for this is geocoding and it is fundamental to all location based services or applications.

There are a number of ways in which geocoding can be accomplished.  They vary in method, degree of difficulty, accuracy and cost.  In a future post, I intend to discuss geocoding in more detail and provide and overview of various approaches that are being used.