Reduced keyboard and method for simultaneous ambiguous and unambiguous text input

Abstract

A reduced keyboard disambiguating system. The keyboard has twelve keys, nine of them labeled with numerous letters and other symbols, and those nine plus one more are labeled each with one of the ten digits. Textual entry keystrokes are ambiguous. The user strikes a delimiting “Select” key at the end of each word, delimiting a keystroke sequence that could match any of many words with the same number of letters. The keystroke sequence is processed with a complete vocabulary, and words which match the sequence of keystrokes are presented to the user in order of decreasing frequency of use. In addition, stems of longer words whose initial letters match the sequence of keystrokes are also presented to the user in order of decreasing frequency of use. The first word in the presented list is automatically selected by the input of the first character in the next word. The letters are assigned to the keys in a non-sequential order which reduces chances of ambiguities. The “Select” key is pressed to select the desired word other than the first word, and spacing between words and punctuation is automatically computed. For words which are not in the vocabulary, a simultaneous unambiguous interpretation of each keystroke is performed to specify each letter of a desired word. The system simultaneously interprets all keystroke sequences as both ambiguous and unambiguous keystrokes. The user selects the desired interpretation. The system also presents to the user the number which is represented by the sequence of keystrokes for possible selection by the user.