We are tackling with the modeling for design and evaluation
of a pointing user interface that supports communications
among people looking or pointing at the same contents on a
large screen or display. The objective system is a user
interface that consists of a gesture measurement process and
its visualization process. In this paper, we introduce the
analysis of the system and users behaviors based on control
theory and users motion and perception characteritics, and
the design of the display scheme for a better performance of
the total system. We then report the results are consistent
with a number of previous works, and paramter adjustment in
our model is useful for improving a pointing support system.