We get the word Shaman from the Tungus word saman associated with the hunting tribes of Siberia and central Asia that are genetically linked to primary groups of Native Americans. While a few remnants of these early hunting societies survive, shamanism itself is alive and well and downloadable off the Internet.
I have just started listening to Christina Pratt’s podcasts, Why Shamanism Now? as broadcast on Seventh Wave Radio. They are a free download on itunes. She makes a distinction between the terms "authentic" and "traditional". Because shamanic practice is a technology used to attain direct revelation from the spirit world, according to Pratt the criteria for authentic shamanism is success in connecting to the spirit world. Because shamanism is the proto religion of the human race these technologies come to us through many different cultural traditions some with more formalized training than others. Being trained in traditional methods is of course going to be helpful in achieving the sought for connection to the spirit world. The traditions alone however are not as critical as actually making the spiritual connection.
The ancient hunters purpose for using shamanism was survival. They relied on direct revelation to guide them toward a successful hunt. My own interest is just as practical. Can shamanic techniques of connecting to the spirit world or the life force help me make a living, pay my bills, live in good health and contribute to my community? And yes, find my spirit animal? This remains to be seen.