Dewey or don't we classify?

I do believe the DDC system is necessary in the school library.  A lot of work and thought has gone into the system with numerous revisions.  I think, if taught probably, students can navigate the school library collection with success.  As mentioned in this week's article, "Dewey or don't we classify?", good signage is key along with instruction of how the use the system.  At our school, the teacher- librarian places the books out on the carpet for the Kindergarten students to select and therefore do not actually browse the books on the shelves. As they get older, they independently search for books, asking the teacher-librarian for assistance when needed.  
As there is only one computer in the library that is located behind the circulation desk, it is common for teachers to ask the teacher-librarian where a book is located in the library and not search for the book themselves.  It seems to not be problematic, as the teacher-librarian is full time at the school and available to help in your search for books.  I could see this as being an issue if the teacher-librarian is part-time or not available and the teacher is wanting to find a book in the library on their own.  Providing opportunities for them (teachers and students alike) to learn the Dewey Decimal Classification system, I believe will serve students well as they progress through the educational system and make them feel more comfortable using the library.