From what I've seen, it looks like you want to pay attention to the "Field Partner" and their rating. These are the local organisations that actually administer the loans "on the ground".
You can actually get a list of all loans that have been defaulted:
http://www.kiva.org/app.php?page=busines...rtBy=Popularity
Usually the "Field Partner" has a low rating in these defaults. So one or two star field partners should be considered fairly speculative. That's fine if you want to go that way, just be aware...
OTOH, you'll see five star field partners who've handled a thousand loans and never had a single default.