Comparison Items

Each item that is potentially a duplicate is associated with one or more comparison items. Comparison items are items processed by the system before the potential duplicate item.

The purpose of the review process is to determine which, if any, of the comparison items is a duplicate of the review item. When an item is determined by the reviewer to be a duplicate, its state is set to duplicate and the next component of payment processing system stops processing for the duplicate item.

The number of comparison items for each review item depends on the items being processed. The following examples describe how the number of comparison items is determined:
No comparison items
When an item is processed and no potential duplicate items are identified for it, the state of the item is set as not a duplicate of any other items. No comparison items exist for the review item.
One comparison item
The key field data values for item Y matches the data for an item, X, that was processed earlier. Item X is the single comparison item for item Y because:
  • item X arrived before item Y
  • the key field values for item Y seem to duplicate item X
More than one comparison item
The key field data values for item N matches the data for the N-1 items that were processed earlier. Item N has N-1 comparison items because:
  • N-1 items arrived before item N
  • the key field values for item N seem to duplicate any or all of items N-1

Although a given item can be a duplicate of more than one item, as far as the review process is concerned, it is only a duplicate of a single item. The fact that it may be a duplicate of multiple items may be important for an analyst, but from practical perspective it is only important that it is a duplicate.