This watchlist was created in 2004 from several other lists and at that time it consisted of about 68.000 entries. I use the word entries, because in the years after it became fuzzy if one record is the same as one individual. By the end of 2008 the list had grown to over 1,1 million entries. In 2008 after the American Civil Liberties Union (ACLU) mentioned that the list had passed the 1 million, the government came with an explanation. Although we have recorded over 1 million entries in the database, the net result is that these records correspond to about 400.000 individuals. Terrorist often use different and thus multiple identities, use several (falsified) passports etc. But adding entries with only the first initials and last name, while an entry of the full first names and last name already exists will result in unwanted side-effects.

We all know, as being interested in data quality and identity resolution, that J. Robinson will result into much more matches (hits) than James Robinson. Indeed the number of found matches will sky-rocket and have to be evaluated manually. Might this be the reason, that we see more and more security personnel on airports?

In the latest audit report of the U.S. Department of Justice about this watchlist one other problem was analyzed. While extensive procedures were made for nominating and adding suspects to the watchlist, there is no procedure for removing people from the list. Based on a sample of almost 70.000 entries and investigation of the individuals an astounding number of 35% omissions was found. People who had died were still on the list, people who were no longer investigated upon, cases which had been closed etc. So this watchlist is growing and growing. Resulting in screening personnel who ensnare many innocent travelers as suspected terrorists. And wasting their time and divert their energies from looking for true terrorists. It seems to me that FBI and TSC can benefit from better Data Governance, what do you think?

In Holland we already have three officially approved manners of naming streets an addresses. Nowadays we have the TNT Post standard, based on the very first publication of the postal code book, and afterwards corrected several times. This naming convention was the basis for the NEN 5825 standard (NEN is the dutch variant of ISO). But the true source of streetnames comes from the municipality and is called “Raadsbesluit”.Due to the different versions this can easily result in five different ways of spelling of the same street, as the example below shows:

What do you think, should we add a new “English” standard to existing standards. What are the pro’s and con’s for having English labels of the streetnames, please add your opinion in the comments. Should we also replace all signs and add the English label for the streetnames? For more information and history of Dutch street names I recommend the following site “alles over straatnamen”.

Persons and companies are very often identified using their address data. But, what do you do if a person has moved from address A to address B. One, thing you really don’t want is that the person is added to database as a new person (INSERT). From that moment a duplicate person or company resides in your system. This should be prevented, by creating searching indexes which include the current and the previous address of the persons and companies in your database.

A common way to solve this is to store all addresses which the person is known (historical addresses). For each address the start-date (FROM …) and end-date (TILL …) should be stored. Especially techniques which are used in Data Warehousing, like dimensional modelling, come into place.

Of course, you also need other identifying attributes to recognize the moved person. Focus on other customer touchpoints like the e-mail address of persons. Nowadays an e-mail is less subject to change then the physical address where somebody lives. A social security number or banking account number are even more precise, but unfortunately in many cases not available.

And, last but not least, if possible make uses of external sources. For instance in the Netherlands the movers index is maintained by TPG (TPG Verhuisberichten). In other countries similar services are available.