OOP in Scheme

When should I use message passing or data-directed programming? What are the advantages/disadvantages of these techniques over the OOP we can find in Java for example.

>>6
muh le stylized quotation marks
u forgot le terrible maymay with le stylized exclamation mark at the end

to le " >>5 guy you gotta combine ' and ' instead of just "
like this!/ ''

`` ''!

le IHBT maymay means ``i have been tooled"

tool is a special codeword maymay of /prog/ that means "i have been le haskelled"
stop haskellin me!