Information matching generally involves the comparison of one set of records with another, to find records in both sets of data that relate to the same person. When it is done by a computer, it is known as data matching. An example is the comparison of a list of people receiving a monetary benefit with a list of people who have been imprisoned. In some programmes, it is the absence of a person in one set of records that is of interest. The process is commonly used to detect fraud in public assistance programmes or to trace people wanted by the State. Less frequently, the technique is used to assist individuals (e.g. to identify someone who has not claimed an entitlement).
A person's privacy can be affected by information matching when agencies are:
If unchecked, information or data matching would seriously undermine people's trust in government. To address the risks, the Privacy Act regulates the practice of information matching in the public sector. It does this by having the following controls put in place: