From MIT OpenCourseWare »  Architecture »  4.273 Introduction to Design Inquiry, Fall 2001:

“In this class we entertain the idea that the making of objects facilitates the development of ideas. Such objects are made in different media – words, physical materials, virtual images — and, in turn, these media afford different possibilities for interpretation and manipulation. For example, it is easy to tear away and add to a clay model, not so easy with one made of hard woods; but it is easier with the latter to establish a regular module or repeating shape or motif. There are several roles that such objects can play: to enable the designer him or herself to visualize and make sense out of the world they see and experience; to permit the designer to visualize and to manipulate ideas under consideration; to facilitate communication with others; and to engage the form, materials and structure of the artifact ultimately to be built. Their generative power for the designer may not depend upon precise correspondence, indeed, early in the design process such objects may serve the design process well by being quite different from the ultimate artifact and by suggesting possibilities to the designer unforeseen at the time of their making. And not all intermediate objects can (or should have to) fill all three roles.”

Design inquiry is too hard in software.