Breed specific playgroups: what are we actually grouping together?

Breed specific playgroups sound perfectly sensible. Put a group of Labradors, Spaniels or Dachshunds together and let them socialise with dogs like them. Except sharing a breed doesn't automatically make dogs compatible. Good socialisation needs a little more thought about the individual dogs involved, what they are learning from each other and, rather importantly, whether they actually want to be there.