[Wikipedia-l] Methods of electing an arbitration committée

[habj]

I recently noticed at Meta - and was a bit surprised - that the BoardVote
extension has been used in elections to the Arbitration Committee att
English Wikipedia. Since several other Wikipedias also have arbitration
committées, but there is no note of these elections can be found on
http://meta.wikimedia.org/wiki/Election_officials_2006 where the elections
to the English Arc Coms are listed along with the elections to the Wikimedia
Foundation Board of Trustees, I suppose the other arbitration committees
have been elected openly on the wiki, the way administrators are normally
chosen.

Why did English Wikipedia choses to have secret ballots in the election to
their arb com? Why have the other wikipedias chosen not to?

On the more general scale:
Why should votes for adminship be open, and votes to the Board of Trustees
secret ballot? Where on the scale between these two types of elections do we
find elections for an arbitration committee?

/habj