A more detailed analysis of these intersecting areas can then be performed. Grid Analysis is the shading grid cells to identify patterns. Polygons can be shaded to look for areas that have a high number of incidents within their borders. This is frequently performed using boundaries that were developed for other purposes, which presents several potential problems. The boundaries of the polygons are usually drawn along major roads.
Crime frequently clusters along major roads.
Another problem with this type of analysis is that the areal units are seldom similar in size. Using grid cells helps eliminate these problems. For instance, ten thefts occurring at a single location would be represented by a single point on a pin map. Using grid cell mapping, all ten thefts would be counted toward the total for the grid cell that would determine the shade of the cell. The smallness of the cells is another advantage in discovering crime patterns within communities.