The main reason is that there are no standard solutions in the field of education. The development of new education can be seen as an eclectic approach. This means the teacher or the designer has to formulate possible solutions and select the best.
In various instructional design models there is focus on design activities. However, it’s not quite clear how these activities can be executed. The models are straightforward procedures there is almost no place for design. This is strange because most people agree that many steps in the development of education has elements like design.
In the field of technology there’s much more clear reference to design activities. Therefore a very careful description is made of the available technical design theories and activities in such a way that the comparable activities and products in educational development can be identified. For example, also in some instructional design models there is the step in which the prototype of the new education is prepared. The question is how does this prototype look like.