When I have a classroom of 28 students in Document Processing I, my students see document processing in many different stages. I emphasize that this course is really keyboarding using the touch method and using orange skins which in the end will increase their keying speed and accuracy immensily provided they follow instructions.In this class we will also learn to format business letters, reports, memos, and ruled tables. I bring concrete concepts to abstract thinking by teaching how each documnet will be used in their choosen career field. Is this what you mean by what role concrete thinkg play in the learning process?