The concept of puppy socialization has really entered the cultural mainstream. People who know virtually nothing about dogs seem to know that puppies need to be socialized. Thats a breakthrough! And overall a good thing. The problem is, the format and marketing of popular puppy socialization classes has led the average dog owner to mistakenly conclude that socialization = dog play. It doesn't. Socialization is about exposing your puppy, from the time you get it, to the sights, sounds, smells and substances of the world we live in. This is best done before 16 weeks based on the very real developmental stages all canines have. Think things like seeing people wearing hats and sunglasses, walking on carpet, linoleum and grass, and walking (in your arms) on a downtown street. The exposures need to be safe and positive, taking into account the unique personality of the individual pup. If more people focused on this broader concept and left the "playing with other puppies" to its place as one tiny piece of a larger process, there would be a lot more harmony in the world we humans and dogs share.