Abstract: A command interface of a machine including a plurality of different control elements each of which generates a different control command when actuated by a user, wherein the plurality of control elements are arranged for actuation by a user and are categorized into different groups including: a first group of control elements including control elements that are most similar, according to a first similarity criterion, to a target control element specified by the user in a prior request; and a second group of control elements including a first additional control element that is dissimilar, according to the first similarity criterion, to the target control element specified by the user in the prior request, and that, when actuated by a user, specifies in a new request the first additional control element as a target control element.