Huffman Coding

A data compression algorithm that assigns shorter codes to more frequently occurring symbols and longer codes to less frequent ones, producing an optimal prefix-free encoding. In accessibility and AAC research, Huffman coding has been applied to the design of scanning interfaces for switch users, where it can theoretically minimise the average number of switch activations needed to select a character by grouping frequently used letters closer to the top of the selection hierarchy. However, empirical research shows that the theoretical efficiency gains may be offset by increased cognitive load and reduced predictability of the scanning pattern.