No matter what deduplication model you choose, it won’t be perfect. Even if you use sophisticated biometrics technology as part of the process of creating a unique identifier, it won’t be perfect. And you must expect that.
The system will flag a duplicate when it isn’t. Additionally, there will people missed in the registration process. Information collect will need updating and correcting. And you must expect that.
Therefore no matter what model used, it must be accompanied by a robust system enabling people to complain, update their information, be added, etc. Sometimes this is considered part of an accountability system. Sometimes it is seen as an ‘add on’ or a ‘kind gesture’. But frankly, it just being human. And it is essential.
Without a doubt, it is the most important part of the entire process.