A very simple but highly effective method of bird identification. Answers to a series of easy questions, starting with size (larger than a robin? smaller than a robin?), prompt the user to pull out computer punch cards with holes corresponding to various possible birds meeting each criterion. When your selection of cards has proliferated and there is only one hole that goes all the way through your stack, you've identified your bird. I used this guide frequently when I was 12 or so, but it disappeared at some point and I would like to replace it. Sometimes it's frustrating to thumb madly back and forth through Peterson's Guide and it would be so much easier to swivel a few cards out of a pack. ( )