The document discusses various methods for evaluating gestural user interfaces (UIs), including comparing a UI to a reference model, collecting evaluation data on usability criteria, and using standardized scales and metrics. Common dimensions for evaluation are goals, utility, usability, and factors like system acceptance, ease of use, and cost. Methods mentioned include observations, questionnaires, heuristic evaluations, and measuring task performance and preferences using standardized scales. Guidelines are provided for designing and assessing the usability of different gestures.