Yes I was surprised about Allen in this poll. Every single poll has him in the single digits. They must be polling right this time.
The method they used just shows a positive, negative, neutral (or none) opinion of the person. It negates "name-recognition", which predominates in the other polls.
You have to keep in mind, most people on that list (like allen) have a 65-75% unknown. These numbers are based on the people who know them. IE if 5% of the population said osama obama deserved a 100 thats how it would be reported.