Given the ubiquity of SmartTVs and head-mounted-display-based virtual environments, recent research has explored techniques to support eyes-free text entry using touchscreen devices. However, proposed techniques, leveraging lexicons, limit the user's ability to enter out-of-vocabulary words. In this paper, we investigate how to enter text while relying on unambiguous input to support out-of-vocabulary words. Through an iterative design approach, and after a careful investigation of actions that can be accurately and rapidly performed eyes-free, we devise DuSK, a {Du}al-handed, {S}troke-based, 1{K}eyboarding technique. In a controlled experiment, we show initial speeds of 10 WPM steadily increasing to 13~WPM with training. DuSK outperforms the common cursor-based text entry technique widely deployed in commercial SmartTVs (8 WPM) and is comparable to other eyes-free lexicon-based techniques, but with the added benefit of supporting out-of-vocabulary word input.

翻译：鉴于智能电视和基于头戴式显示器的虚拟环境的普及，近期研究探索了利用触摸屏设备实现无视觉辅助文本输入的技术。然而，现有基于词典的技术限制了用户输入非词汇表单词的能力。本文研究如何通过依赖明确输入的方式实现文本输入，以支持非词汇表单词。通过迭代设计方法，并深入分析能够准确快速执行的无视觉辅助操作，我们提出了DuSK——一种{双}手操作、基于笔{划}的1{键}盘输入技术。在对照实验中，初始输入速度为每分钟10个单词，经训练后稳步提升至每分钟13个单词。DuSK性能优于商用智能电视广泛采用的基于光标的文本输入技术（每分钟8个单词），并与其他基于词典的无视觉辅助输入技术相当，同时具备支持非词汇表单词输入的附加优势。