I've always been interested in play. Science doesn't explain it very well, or it's explained as something young animals do to practice future skills. But that definition doesn't cover every kind of play, and it doesn't explain why it's so much fun, so reinforcing in itself.
One thing clicker training gives us is a new level of trust and communication. You may have noticed this with your pets. It's particularly startling and, to me, touching, with captive animals that could never be pets; it makes their entire care much more humane.
Writing a book is like having a baby. There is never a convenient time to do it. It's much more work than you remember from last time. And it usually takes longer than you thought it would.
For six years I have been writing a monthly letter to you. In the beginning, back in 2002, "Karen's Letter" was usually about new products and events, but gradually I began using the letter to talk about the science of training, and about the impact of the new technology we are developing from that science.