I know what your saying, however yesterday I had two students ask why their projects legs were shorter than the other students. Some weeks back I had given them another part of the project instead of the correct pieces. I have each component placed on storage racks and clearly labeled. In the same class I gave instructions to a student what to do next and it was for a different project and different year level. Embarrassing. I don't make those mistakes. I don't know what....but something's not right.