The Hot Spot Analysis and Optimized Hot Spot Analysis tools are traditionally used with polygon data. However, there may be times when your source data is represented by point locations. These locations may or may not have applicable attribute information.
There are two ways to handle this situation. If you have a suitable boundary layer such as census tracts or blocks, ZIP codes, or other political boundaries, you can aggregate the point data to the boundaries and then perform the hot spot analysis. You've already seen some examples of this. But there may be times when you don't have a suitable boundary layer to aggregate the points or simply want to use the point layer instead. In these situations, you can use the Optimized Hot Spot Analysis tool to create a fishnet of rectangular features to use as the aggregation layer...