Fundamental principles and priority setting for universal usability

There are a number of interrelating factors that must be considered and weighed against each other when deciding which features or capabilities should be added to a product to increase its flexibility and usability by a wider range of users. Not all strategies or approaches are created equal, and designers have limited resources in developing and improving products. It is, therefore, important that the different dimensions of usability be understood and that priorities be applied appropriately. This paper attempts to delineate some of the key dimensions of usability and to begin the process of providing a rationale for prioritization between possible changes to a product's interface. The paper discusses a multidimensional prioritization approach that is coupled to a vector-based usability evaluation procedure currently being developed.