This sites received 91,000 hits per year. My page on hexagonal grid analysis receives a consistent percentage of these hits.
The reason is the description on how to use and manipulate the hex grid method of mapping, my arguments as to how it reduces error production in spatial analysis by 25% +/-, and the value of downloading the hexagonal grid modeling tool that I posted 5 years ago, for students in search of a unique final project.
I developed this method of analyzing health in the winter of 2002/3, twelve years ago.
It was successfully applied at the state level to demonstrate the spatial relationship between exposure to chemicals and leukemia/lymphoma case reporting.
The isolines that are developed from hexagonal grids are more accurate and visually appealing than those generated using a traditional square cell grid technique.
A fairly detailed statistical analysis I performed comparing square cell grids to hex cell grids demonstrated there to be a 42% of error with square grid cells due to corner-centroid spatial relationships. With hex grids, this relationship is reduced to 16%-17% potential for error in spatial assignments.
The hex cell method is by far more reliable and useful than the traditional square cell method, yet 90% or more of GIS analysts rely upon the more error prone older methods.
The number of visitors at my site on medical GIS for hex grid training is unique, and consists mostly of students, who are engaged in some sort of GIS lab project or producing a project in GIS to hand in as a term project or paper.
One way to understand the ingenuity of a GIS user is to determine how exposed and familiar he/she is to the applications of grid modeling, and the benefits of hex grid methods over square grid methods.
For grid mapping spatial analysts, until hex grid cell methods are employed, esp. for medical GIS, we will always be dealing with the >40% spatial error problem for our work.
The major advantage of grid mapping is that it does not require base mapping, or even the use of a background GIS to produce your results. With the hex grid method, we could avoid the need for a regular GIS to produce our results (a popular early 1990s philosophy amongst us grid analysts), but hex grid mapping techniques provide a greater benefit and more useful graphic output when developing using a standard vector GIS tool for the spatial analysis.