Answers to these and other questions help management efforts. Another important question the counts answer is where the irruptive species are. Irruptive species are birds that migrate to an area where they ordinarily wouldn't be found. As the weather warms, our feathery friends will be winging their way back to home territories. Having this event at the end of winter allows surveyors to document the distributions and number of birds before March's migrations begin.
Every participant is important.
It doesn't matter whether you count just a few that visit your yard, or you do more. The important thing is to get out and enjoy the experience. That helps in observing accurately. If you aren't an avid bird-watcher, get to know a few basic species. Locate a copy of Petersen's Field Guide to Birds of North America, or any publication that has good quality photographs or drawings.