I'm on a bit of a Seagal kick of late. I'll get back to my knife survival series soon.
This is a great video of Steven Seagal in his earlier years and of his teaching style. Seagal Sensei believes that randori (free, or spontaneous practice) is an essential part of truly testing your skills. I agree and have posted on the lessons and the importance of randori here.
Of particular note is the absence of a mimicked sword in the attacker's hands. It's there occasionally, which references the style's time, history, and concepts of movement, but more realistic forms of attack are more prevalent, which I think is important. Aikido can be used effectively in real world attacks, as if often evidenced here.