Kim Lowell is Professeur titulaire in the Centre de recherche en géomatique, Université Laval.
Effect(s) of the “No-Same-Color-Touching” Constraint on the Join-Count Statistic: A Simulation Study
Article first published online: 3 SEP 2010
1997 The Ohio State University
Volume 29, Issue 4, pages 339–353, October 1997
How to Cite
Lowell, K. (1997), Effect(s) of the “No-Same-Color-Touching” Constraint on the Join-Count Statistic: A Simulation Study. Geographical Analysis, 29: 339–353. doi: 10.1111/j.1538-4632.1997.tb00969.x
- Issue published online: 3 SEP 2010
- Article first published online: 3 SEP 2010
The join-count statistic is used to measure the tendency of polygons of a given map type to attract or repel polygons of the same or different map types. Yet in certain maps—for example, natural resources maps—it is often impossible for a polygon of a given type to touch another polygon of the same type. (This is the no-same-color or “No-Same-Type-Touching” (NSTT) constraint referred to in the title.) This violates an underlying assumption of the join-count statistic and may render its use to study certain spatial phenomena inappropriate—even for measuring spatial autocorrelation among polygons that are not the same type. This was explored using Monte Carlo simulation. For polygons of different types, it appears that results of the join-count statistic can be interpreted without any special consideration for the NSTT constraint provided there are a minimum of five to eight colors in the spatial system. For polygons of the same type, results can simply be ignored since it is known that no two polygons of the same type will touch.