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Joanna Helga


Publications by Joanna Helga (bibliography)

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MacKenzie, I. Scott, Soukoreff, R. William and Helga, Joanna (2011): 1 thumb, 4 buttons, 20 words per minute: design and evaluation of H4-writer. In: Proceedings of the 2011 ACM Symposium on User Interface Software and Technology 2011. pp. 471-480. http://dx.doi.org/10.1145/2047196.2047258

We present what we believe is the most efficient and quickest four-key text entry method available. H4-Writer uses Huffman coding to assign minimized key sequences to letters, with full access to error correction, punctuation, digits, modes, etc. The key sequences are learned quickly, and support eyes-free entry. With KSPC = 2.321, the effort to enter text is comparable to multitap on a mobile phone keypad; yet multitap requires nine keys. In a longitudinal study with six participants, an average text entry speed of 20.4

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