Unfortunately some pilots clutter up the airwave with unneeded position reports. If there's two aircraft in the pattern you pretty well each know where the other is, no need for announcing every leg. Someone could take off or approach and get stomped on by a needless call. The problem with student pilots is they are trying to listen to their instructor and aren't paying close attention to other airplanes. So if I am in the pattern and someone starts all the obligatory position reports I stop making most of them myself and watch that aircraft like a hawk, they obviously aren't watching me. I have noticed experienced pilots will only make a minumum number of position calls in the pattern. Also, the more aircraft in the pattern the faster a call should be made when it is made. Another trick you can do is say "I have the so and so in sight" and let the specified airplane off the hook as far as his position report goes on that leg.