People in Latin cultures usually carry as a surname
either the first part of the surname (mostly Spanish) or the last part of the surname (Portuguese) of
each of their parents. These customs were more consistent in the past. What are the consequences
of viewing this as two surnames? No native record keeper would knowingly analyze such a surname
into two pieces and choose one of them to record. But here there is a different justification for
splitting the name apart. Keeping value specific weights for every possible combination would seem
impractical. Thousands of name pieces become millions of combinations. Apparently we can
estimate the value specific weight for the combined form in the surname field from that of its
constituents as in equations 5.10 and 5.11.
aw = log2 [r ÷ (c1 × c2 × 6 ) ]
(5.10)
dw = log2 [(1 – [r ÷ 6 ] ) ÷ (1 – [c1 × c2 ] ) ]
(5.11)
We use the same logic as in the ¶ 5-4.10 above, and a factor of 1/6 as discussed above in ¶ 5-4.9
since there is not just one person carrying the name; all the children of the union share the same
compound surname. (NB: In certain cultures another fraction would be more appropriate.)
