This page indexes the description of the SRS system in the Physics Lecture
Hall, which enables the instantaneous gathering of responses by students
into a computer on the lectern. The system is based on a continuous polling
of the keypads at each student's seat, and the setting of the state of the
three lights. An elaborate hierarchy clusters these signals, eventually
interacting with the higher level program by adjusting an array of student
responses and reading an array containing the desired state of the LEDs on
each student station. The software for communicating between these arrays
and the student stations I call the lower-level software, and is considered
a fixed part of the system. The software for communicating between these
arrays and the instructor, and perhaps a projected screen for the students,
I consider the higher-level software, and I expect there will be many
versions available, hopefully written by or in collaboration with a large
number of instructors, to provide pedagogic flexibility.