Substitutions show the common connections that items share. They both have the same “friends” but are not found together in a transaction. Items that are substitutes could possibly replace each other in the same basket of transactions.
The upper left hand side of the screen contains the Categories. These are ordered by default by Strength. It can also be alphabetized by Category name. Simply click on the A-Z and the display will update. To change it back click on “By Strength”.
Emcien’s Strength ranking is a proprietary measure the Pattern Detection Engine assigns to connections within an analyzed data set.Think of Strength as a metric that combines Cluster Frequency, the number of times that a specific group of items has occurred in a transaction together, and Correlation, the rate of co-occurrence shared by a selected item and the cluster being displayed.
When a category is selected it will update the upper right hand side to show the items in that category along with the items that have substitutions.
The key of Substitutes is that the 2 Light Blue items are not found together in a transaction, and the “friends” that they share are their only “friends”. This means that one item could be substituted for the other.
If one of the categories on the right is selected it will become highlighted and the lower detail screen will be updated. The outside Light Blue icons are the substitutes. The gray icons in the middle are “Friend” items found with either of the Light Blue items.
The detail also shows the total number of transactions for each item and the number of friends being displayed. Also being shown in the detail is the Strength of the substitution as mathematically calculated by Patterns.