observing fellow teachers

while i am studying to be an art teacher, I've learned to watch my other art teachers that i have classes with to pick up pointers on how to do things. one of my biggest things I've learned is how to successfully construct group work in a lesson. for example, one of my teachers started out a lesson by having all the students create a concept and research that concept for a project. then she wanted us to do prototypes of that concept that we had been researching on for weeks. when you think your done your not because she springs on you the fact that you are now going to be working in groups, and now you have to collaborate your what you thought finalized ideas together and create one object. so now that you have done all that work individually you are put right back to square one because now you have several ideas from several people at once instead of your original idea. this method of group work causes friction between the students because they all want to see their input of ideas shown in the project. when realistically that might not happen since they originally didn't work with each other in the beginning of the project. do you agree with this method of group work? or do you prefer that the students work together from the start and progress with their own ideas together as a whole throughout the project?