In New York, you must be a registered Democrat or Republican to vote in the primary election; a portion of the 16 percent from that district might not know that. New Yorkers registered with a third party, such as the Green Party, Independence Party, Libertarian Party or Working Families Party, can't vote in the primary.
Collaborative filtering (CF) is a method used by some recommender systems. It consists of two senses, a narrow one and a more general one. In general, collaborative filtering is the process of filtering for information or patterns using techniques involving collaboration among multiple agents, viewpoints, data sources.
Filtering is the removal of all visual particles and matter from the water such as dirt, leaves, insects, etc so it can be properly purified and then safely consumed. Purifying is the removal of all invisible bacteria, germs and other harmful elements from the water so it can be safely consumed.