User-centered development of a Web-based preschool vision screening tool.

User-Centered Development of a Web-Based Preschool Vision Screening Tool David P. Taylor, MS1 , Bruce E. Bray, MD1 , Nancy Staggers, PhD, RN, FAAN 1 , Richard J. Olson, MD2 1 University of Utah, Salt Lake City, UT; 2 University of Iowa, Iowa City, IA Although amblyopia is most successfully treated when detected in early childhood, many preschoolaged children are not being screened. This project explored the delivery of Web-based vision screenings, integrated with patient education, to parents and children, aged 3 to 6 years. Through a user-centered design methodology involving requirements gathering, iterative prototype development, and usability testing, a highly usable screening Website was created. Interviewing and testing parents and children in the home were essential in gathering accurate data about environments where the tool would actually be used. Frequent iterations of designing, testing, and modifying the tool were useful in identifying and correcting usability problems. Usability goals were set early in the project, and in the final phase a satisfaction questionnaire was administered to participants. Twenty-one out of 22 final usability objectives were achieved and the feasibility of Web-based vision screening was demonstrated. INTRODUCTION Amblyopia is “a nonspecific loss of visual acuity of at least two lines of difference that is not caused by pathology nor correctable by ordinary refractive means.”1 Approximately 2.5% of the world’s population is affected with amblyopia, which is more than 7 million people in the United States alone. 1,2 Amblyopia has also been reported to be the leading cause of irreversible monocular vision loss in adults between the ages of 20 and 70 years, and before the age of 45 years, it causes more vision loss than all other ocular disease and trauma combined.1,3 Chances for improvement or full recovery are increased when the condition is detected and treated before about 9 years of age when vision is mature. Vision screening of preschool children has been advocated as a means for early detection. However, in the United States, an effective mass screening program has not yet been achieved and it is estimated that fewer than 25% of preschool-aged children receive vision screenings either from a government or private program. 4 In addition, up to 60% of primary care providers do not perform vision screening on preschool-aged children, and others perform screenings inconsistently.4 The purpose of this study was to create a highly usable Web-based vision screening tool for parents to screen their preschool-aged children (3 to 6 years) for amblyopia, to learn more about this condition, and to find ophthalmologists in their area. Providing screening in the home was the focus of this research but the tool could easily be adapted for preschools or other settings. This site (www.lazyeyetest.org) was envisioned as a free, public service, with no ties to a particular clinic or advertisements for any products or services. METHODS It was important to maintain a focus on the needs of the end users in building an easy to use screening tool. In traditional software design actual users are often involved infrequently or too late in product development to make a difference. Consequently, user interface issues and usability testing are often only superficially addressed. A contrasting approach, user-centered design, is guided by three distinguishing principles: (1) An early focus on users and tasks, (2) empirical measurement of product usage, and (3) iterative design whereby a product is designed, modified, and tested repeatedly.5 Direct contact between users and designers occurs throughout the development lifecycle and emphasis is placed on measuring ease of use and ease of learning through the iterative development and testing of prototypes.6 The main phases of the project were completed as follows: A. User needs analysis/requirements specification B. Low-fidelity prototype development/exploratory testing C. Website development/assessment testing D. Final usability verification testing Institutional Review Board approval was obtained and in each phase approximately 6 parents and 6 children participated in interviews and usability testing. Most participants were newly recruited in each phase. Within each phase, 3 children were included with known amblyopia and 3 with normal vision or unknown vision status. This technique utilizing a small number of participants, sometimes called “discount” usability testing, has been shown to be effective in detecting 85% of usability problems in a design.7 AMIA 2003 Symposium Proceedings − Page 654 The main goals of the user needs analysis/requirements specification phase were to determine the characteristics of parents and children who would be using the site and to create a list of technical specifications. Meetings were arranged with parents and children in the home and data were collected through a background questionnaire, semistructured interviewing, and an analysis of the homecomputing environment. Variables such as monitor size and resolution, Internet connection speed, room lighting conditions, and distance in front of computer screen were measured to determine the baseline technological requirements for the site. Measurement of visual acuity was selected as the screening method for this study and the Amblyopia Treatment Study visual acuity testing protocol was used as a model for adaptation.8 Usability goals were constructed to be measured in the final phase with a user satisfaction questionnaire. Examples include: (1) the home page is convincing that preschool vision screening is essential, (2) the instructions for setting up the test are easy, and (3) the test results are clear and helpful. During this phase the decision was also made to link to an existing physician locator site.9 In the second phase a low-fidelity prototype of the site was created using PowerPoint. Low-fidelity prototyping is a technique used early in development to produce simple, cheap, and quick mock-ups that help support the exploration of alternative ideas and designs.10 We met with parents once again in the home, walked through the prototype screen by screen, and recorded their feedback. The low-fidelity prototype phase provided a strong foundation for the actual development of the site. Although the main portion was built in HTML, Macromedia Flash was used to implement the actual vision screening because of its excellent interactivity and ability to provide high-quality animation requiring minimal network bandwidth. ColdFusion was used for data transfer to an MS Access database. Usability testing was accomplished by observing parents and children while they used the site and parents were asked to “think aloud” to reveal their decision making process as they accomplished tasks. Data were collected on problems observed as participants used the site, their comments during testing, and their answers to debriefing questions. (...truncated)