AddressLink  Address Matching Software AddressLink is a software web service developed by BizMaps that provides the most accurate and highest match rates to the GeoDirectory. The GeoDirectory is a database (a joint An Post and Ordnance Survey initiative) that contains the address and map coordinates of over 1.7 Million addresses, every building in the Republic of Ireland. The database is updated by An Post postal workers, with official updates released on a quarterly basis. Address Matching Process BizMaps’ AddressLink software takes an address in an unstructured format and matches it to the GeoDirectory. The underlying software has been developed over the last decade, with continuing development to increase the accuracy of the matching process. The matching process is performed according to the following Quality Controlled Methodology Structured Matching Addresses are processed from right to left or bottom to top. As each element of an address is identified, the universe of potential matches is reduced. Thus, when the town has been identified, the only streets that can possibly match are associated with that town. No address elements are “skipped” As we read right to left, if an element cannot be matched, the process stops. The following are two different addresses and it is obvious how skipping Rathmoyle would cause an error:   9 Abbeyleix Road, Rathmoyle, Portlaoise, Co. Laois   9 Abbeyleix Road, Portlaoise, Co. Laois The universe of addresses that is searched is reduced as we match, thus only roads/streets in Portlaoise would be searched to locate Abbeyleix Road in the second example above. Unique Irish Pattern matching algorithm Bizmaps has developed an algorithm that handles differences in the spelling of Irish place names. ‘Soundex’ is not employed, as this has proven to lead to incorrect matches, instead a large number of rules have been developed that define allowed matching. Examples of these are shown in table below. Allowed Match Rule St Anne Terrace = St Annes Terrace Extra ‘s’ on word Old Town = Oldtown Missing space Parteen Road = Patreen Road Reversed letters, not first letters Phibsboro = Phibsborough Ending in ‘ough’ instead of ‘o’ Charleville = Rathluirc Matches to an alias These rules have been developed over time by analysing millions of address mismatches and testing each rule to ensure it doesn’t introduce any incorrect matches. All exceptions are stored in a patternmatch exception list, e.g. Clonee can’t be changed to Clones. Hit Codes As Bizmaps’ matching is structured, a ‘HitCode’ field is provided that denotes the lowest level to which an address was matched. This allows a detailed breakdown of an overall Geocoded or Matched Rate that is provided. AddressLink Northern Ireland For Northern Ireland AddressLink matches to postcode level based on data from the Pointer database (GeoDirectory equivalent).