methods of and systems for entering ambiguous text input via a linear character selection display are provided . a system for entering an alphanumeric string includes presentation logic for displaying on a presentation device an alphabet arranged into a row of letters and indication logic for presenting visual cues grouping a series of letters of the row into a cluster . the system also includes navigation logic for receiving user actions to move the visual cues along the row of letters to change the letters grouped into the cluster . the visual cues move along the row of letters in variable offsets based on a rate of input of the user actions . the system further includes selection logic for receiving user actions to select the cluster of letters to cause at least one of the letters of the selected cluster to be displayed in a string field .