I came across this section of red wall on Folsom Street anonymously "decorated" with white chalk. It's structured yet lively and spontaneous. Funny how chalk continues to be used even though other drawing materials are more convenient and readily available.
Stylish restaurants sometimes use chalk on blackboards to show the changing menu and perhaps to evoke simpler times and establish a happy mood. Most people have used chalk at some time in their lives -- probably as a child and for most those were happy times. You can't use chalk without being aware of its sensual and tactile qualities, the way it engages the surface and reveals textures, the sound of chalk grinding on the surface, the way it breaks if you press too hard, and the way it leaves powder on your hands so you know you have drawn.
I try to think about architecture and how the design of things and materials can evoke feeling within ourselves. My first courses in architecture at UC Berkeley explored just these concepts and although it didn't seem "serious" at the time, those exercises still inform my work at Mock/Wallace.