Henderson observes that engineers have developed practices which have long depended upon the use of hand-drawn sketches. Many of the CAD systems Henderson observed create isometric objects, frustratingly useless to mechanical engineers. This boundary between old and new design methods is not always so clear cut. In fact, the engineers studied by Henderson have adapted some of the newer practices while retaining many of the older methods, not out of habit, but as a coping mechanism. Henderson's training in art gives her a useful transdisciplinary empathy for her subject.
Visual literacy is an important component of the practice of engineering.
It is not unusual for a design idea to begin as a rough sketch on a napkin, later to be revised and cleaned up through several renderings before the final design is presented to a client. Thus, learning to draw is as important to the engineer as learning to write is to an historian. Change the nature of the chief currency and the entire network is profoundly changed. I found this insight particularly interesting. While historians do not rely to the same degree on visual objects, we most certainly do have our own boundary objects.