Requirements

CS408 Human Computer Interaction Lecture 23 focuses on the Requirements Definition phase of Alan Cooper's Goal-Directed Design process, bridging the critical chasm between user modeling and interface framework formulation. In this module, Virtual University students learn how to translate persona goals and behavioral insights into structured design requirements. The methodology leverages narrative storytelling as an ideation tool, recognizing that interaction design fundamentally deals with human behavior unfolding over time. Storytelling stimulates creative visualization, allowing design teams to explore interaction possibilities fluidly on whiteboards without becoming constrained by premature technical implementations. The lecture highlights the vital distinction between persona-based scenarios and traditional software engineering use cases: while use cases describe transactional system responses and internal data states, goal-directed scenarios depict how real humans interact with a product to achieve specific personal goals, capturing non-verbal dialogue and cognitive workflow. The Requirements Definition phase determines 'what' the product must do before defining 'how' it operates, following a disciplined five-step workflow: drafting problem and vision statements, conducting unconstrained brainstorming, analyzing persona expectations, constructing context scenarios, and extracting requirements. Problem and vision statements define the business rationale and project scope while balancing organizational targets with user goals. Brainstorming encourages uninhibited ideation to exhaust preconceived ideas and stimulate novel solutions. Analyzing persona expectations involves studying user mental models, domain metaphors, and emotional attitudes. Teams then construct Context Scenarios—broad, day-in-the-life narrative walk-throughs that establish the primary touchpoints a persona has with the system. The handout illustrates this through Salman, a Lahore real-estate agent using a convergent smartphone to manage client appointments, view property listings, and attend to family calls on the move. Context scenarios remain broad and shallow, deliberately treating the interface as an idealized 'magic black box' to avoid bogging down in widget mechanics. From these narrative scenarios, designers systematically extract user needs rather than tasks. Needs are categorized into Data Needs (the essential informational objects, photos, schedules, and status indicators that must appear), Functional Needs (operations performed on objects that eventually become buttons and commands), and Contextual Needs (spatial groupings, environmental dependencies, and uninterrupted device transitions). Finally, the design team synthesizes external constraints, integrating business requirements such as launch deadlines, technical requirements including processor power and display resolution, and customer requirements regarding licensing and maintenance. This comprehensive module directly prepares students for CS408 midterm examinations, solved past papers by Moaaz and Waqar Siddhu, and professional UX requirements engineering.