The EM vote on single-winner methods

[Marcus Ganley]

As someone who hasn't contributed before, I appreciated the 
definitions provided.  As an Australian, studying in New Zealand, I 
am used to somewhat different terminology in some cases, and it was 
particularly useful to have it clarified what was meant by each term. 
 For example the letters "MPV" meant nothing to me,  though I have 
used this system in both State and Federal elections in Australia.  

This leads to one question, though.  In elections for the Australian 
House of Representatives and all State Lower Houses bar Qld and 
Tasmania, we use Compulsory Prefential Voting (often "CPV")  ie 
failure to allocate a preference to all candidates invalidates the 
vote. In elections for Queensland's unicameral parliament  we use 
Optional Preferential Voting ("OPV") - you can truncate at any point. 
 Does the MPV system discussed on this list compel the allocation of 
preferences?