andheld devices such as smartphones and tablet computers now have powerful processors, large screens, and built-in location sensors and cameras. Such features make these devices convenient platforms for augmented reality (AR)-the seamless integration of virtual objects in real environments. Handheld augmented reality (HAR) affords many new ways of interacting with digital content, with applications in various industries such as entertainment, marketing and sales, education and training, navigation and tourism, and social networking. Although several applications have been adopted by general consumers, HAR remains limited and researchers are continuously developing more intuitive interactions using handheld devices. Usability refers to how well target users can use a system's functionality 1 to accomplish a specific task. Usability studies are important for assessing and iteratively improving AR systems. 2 Among the widely used evaluation technique in user studies are subjective measurements such as questionnaires, user ratings, or judgments. For AR systems, researchers have used the System Usability Scale and the NASA Task Load Index to quantify general system usability and workload, respectively. For handheld devices, the Mobile Phone Usability Questionnaire (MPUQ) enumerates the various questionnaires for common uses of mobile phones. 3 These questionnaires have been previously evaluated, and studies support their validity and reliability. However, these standard questionnaires do not consider specific perceptual and ergonomic issues common to HAR systems. As such, researchers complement these evaluation tools with their own questionnaires, but many have not been tested for validity and reliability. Moreover, the questions tend to be specific to the features of their HAR system. (See the "Related Work on Usability Issues in Handheld Augmented Reality" sidebar for more details.) In response to the lack of valid and reliable evaluation tools for HAR, we developed the HAR Usability Scale (HARUS), which consists of two subquestionnaires, namely the comprehensibility scale and the manipulability scale. We designed the questionnaires based on a review of usability evaluations of HAR systems. We then evaluated the validity and reliability of the HARUS in four experiments, and here we discuss some insights gathered from using the HARUS in our own user studies. Researchers and professionals involved in developing HAR applications can directly use our questionnaire to evaluate their own HAR applications or modify it with the insights we present in this article. To create the HARUS, we followed a five-step method for developing and testing questionnaires. Usability evaluations are important to improving handheld augmented reality (HAR) systems. A HAR usability scale that consists of comprehensibility and manipulability scales can help measure general system usability, ease of understanding the information presented, and ease of handling the device.
Santos designed a questionnaire for usability evaluation (HARUS), which was composed of two sub-questionnaires, namely the comprehensibility scale and the manipulability scale REF .
Toward Standard Usability Questionnaires for Handheld Augmented Reality
IEEE Computer Graphics and Applications
IEEE Computer Graphics and Applications
Computer Science Medicine