On-line Demo
The test data used by the demo system is derived from the Third Edition of the British National Burial Index (NBI). This contains some 18 million entries taken from parish registers, representing some 490,000 different surname spellings.
The demo system currently allows searches among the top 16,600 surnames, i.e. those with a frequency of 100 or more occurrences in the NBI database. The frequency of each variant is also given in the results table.
The data is stored on-line in a MySQL database as a large number of scored pairs, the average number of variants for each surname being around 165.
Results are presented in ranked order, from exact match down to 80% match. The percentage shown is a notional value calculated by the matching algorithms used. The algorithm does in fact calculate values to a lower degree of match, but these are less likely to be useful in practice.
In a working system one might well offer a number of categories to the user such as 'Exact Match', 'Close Match' and 'All Matches'. These might be assigned ranges of percentages such as 100% match, 100%-90%, 100%-80% respectively.