This paper introduces real time inverse arithmetic coding and user interfaces
based thereupon. The main idea is that information-efficient data entry can be
achieved by ensuring that each input's associated display space and ease of
selection are at all times related to the input's probability of being
selected. As with data entry based on inverse arithmetic coding, the layout
initially depends on the probabilities of the possible inputs; however, real
time inverse arithmetic coding differs in that the user's actions are
interpreted not to navigate this probability distribution but rather to modify
it according to a learned update rule, which approximates the conditioning of
the probability distribution on the user's actions. Potential applications of
real time inverse arithmetic coding include text entry, file browsing,
integrated multi-program user interfaces, assistive technologies for users with
movement disabilities, and ergonomic input methods.