Complex productivity applications that integrate tasks in the workplace are becoming more common. Usability typically focuses on short-term, immediate measures of task performance. This study incorporates a long-term goal of more durable learning, focusing on implicit learning (spontaneous, unplanned, usually unconscious learning as a result of other activities). It looks at how the design of complex applications can facilitate such incidental learning of both the application and the task domain when a conceptual model of the task domain is intentionally embedded. This can lead to more productive communication lower development and training costs, and improved task performance. The study targets the navigation interface as a gateway to exposing structural knowledge about the task domain as well as the organization of the application. Schema theory and cognitive load are discussed. The study used an application developed to design and manage lessons in large training programs. The application reflected an explicit conceptual model of Instructional Systems Design (ISD). The experiment was conducted over the internet and exposed a range of users to application tasks using one of three. navigation interfaces. These menus reflected the underlying model to different degrees; content pages were the same. The pre-test assessed participants' understanding of the embedded model as a baseline. A series of typical application tasks ensured exposure to concepts. Performance and subjective data were collected to assist interpretation of results. The test, a multiple choice version of concept map assessment, was then repeated to show changes in model alignment. Despite very brief contact time, the study confirmed that application interaction led to learning and greater alignment with the embedded model on all three measures: relationships, sequence, and vocabulary. Interaction was influenced by the cognitive load of high perceived difficulty and unfamiliarity and by the dominance of time spent on content pages over navigation time. Trends indicate a preference for constant menu visibility, familiarity, and simplicity (low informational density). Performance and learning for treatments reflecting the embedded model faired better than the standard Windows menu which shows only the application organization, not the embedded model. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]