  Multi-touch input technologies are becoming popular with the increased
interest in touchscreen- and touchpad-based devices. A great deal of work has
been done on different multi-touch technologies, and researchers and
practitioners are frequently coming up with new ones. However, it is almost
impossible to compare such technologies due to the absence of multi-touch
performance metrics. Designers usually use their own methods to report their
techniques' performances. Moreover, multi-touch interaction was never modeled.
That makes it impossible for designers to predict the performance of a new
technology before developing it, costing them valuable time, effort, and money.
This article discusses the necessity of having dedicated performance metrics
and prediction model for multi-touch technologies, and ways of approaching
that.
