These byproducts of behavior can be further defined by the concepts of erosion, leftovers, and missing traces. A simple example of erosion on campus is the worn paths that students make as they find the shortest distance between campus buildings. Worn carpet in front of the campus welcome center is another example of erosion that has greater negative impact on institutional image. Leftovers are traces represented by objects not consumed in the behavior. Trash and litter are the most common examples.
Leftovers can also become associated with particular campus groups.
Many campus spaces have been designed in such a manner that they are never used by people on campus. Further observation indicated that the entry to the lounge was hidden and uninviting. As a result of some minor redesign, use of the lounge increased and the behavioral traces of erosion and left-overs began to appear. The physical environment is changed to better accommodate campus behavior. Campus adaptation for use would include renovations, expansions, and other changes or improvements.