This chapter presents a method for the evaluation of user interfaces for mobile applications. The method is based upon an approach that combines user opinion, standard conformity assessment, and user performance measurement. It focuses on the evaluation settings and techniques employed in the evaluation process, while offering a comparison between the laboratory evaluation and field evaluation approaches. The method’s presentation and the evaluation comparison will be supported by a discussion of the results obtained from the method’s application to a case study involving a Personal Digital Assistant (PDA). This chapter argues that the experience gained from evaluating conventional user interfaces can be applied to the world of mobile technology.
Key Terms in this Chapter
Conformity Assessment: A collective term used for a number of techniques used to determine if a product, system, or process (including design) meets a defined specification.
Virtual Network Computing (VNC): A desktop sharing system that uses the RFB (Remote Frame Buffer) protocol to remotely control another computer. It transmits the keyboard presses and mouse clicks from one computer to another over a network, relaying the screen updates back in the other direction.
Likert Scale: An attitude scale in which respondents indicate their degree of agreement/ disagreement with a given proposition concerning some object, aspect, person, or situation.
Multi-Layered Evaluation Approach: A product or prototype usability evaluation method that combines techniques for data gathering and analysis based on multiple perspectives (the user’s, the specialist’s, and the usability community). The results are overlaid in order to find discrepancies and offer more robust results.
User Satisfaction Measurement: The process of obtaining qualitative and quantitative information which indicates the extent to which user expectations concerning some object, process, product, or situation are being met. Such information can be obtained in a variety of ways, both formally and informally.
Efficacy of an Evaluation Method or Technique: Translated into the number of problems found, gravity of those problems versus the time, and cost of performing the experiments.
Device Mobility during a Usability Evaluation: The ability to interact with the user and continue to perform its functions while being transported.
User Performance Measurement: The process of gathering actual data from users as they work with a system and its documentation. Usually, the user is given a set of tasks to complete and the evaluator measures the relevant parameters such as the percentage of tasks or subtasks successfully completed, time required to perform each task or subtask, frequency and type of errors, duration of pauses, indications of user frustration, and the ways in which the user seeks assistance.
User Mobility during the Usability Evaluation: The ability to move while performing a task with a product.