Chapter 12: Design, Prototyping & Construction

The chapter focuses on the Develop phase of the iterative design process, detailing the core activities of design, prototyping, and construction. Design is divided into two intertwined areas: conceptual design, which centers on establishing the product’s overarching conceptual model, defining what it will do and how it will behave, and concrete design, which specifies the detailed attributes of the interface, such as visual appearance, layout, navigation, and input/output modalities. Essential considerations during concrete design include accessibility and inclusiveness, ensuring the product is usable by the broadest range of people, including those with disabilities, and designing for different cultural contexts. Prototyping provides a concrete manifestation of design ideas, enabling designers to communicate concepts and users to provide feedback early in the process. Prototypes range across a spectrum of fidelity: Low-fidelity prototypes do not fully resemble the final product but are quick and cheap to produce and modify, making them ideal for exploring initial ideas. Low-fidelity techniques include storyboarding (sketches illustrating task progression), sketching (focusing on design intent), index card prototyping (cards representing screen elements or dialog), and Wizard of Oz (where a human secretly simulates the system's functions). In contrast, high-fidelity prototypes look and function more like the finished product and often evolve through integrating existing hardware or software components. Prototyping inherently involves compromises, such as horizontal prototyping (broad functionality with little detail) versus vertical prototyping (deep detail for only a few functions). The conceptual model is constructed by choosing suitable interface metaphors (like the restaurant metaphor for a travel organizer), selecting appropriate interaction types (instructing, conversing, manipulating, exploring, or responding), and considering different interface types (e.g., tangible or virtual reality). Initial models can be expanded by determining task allocation between the product and the user and defining data requirements, often captured initially in wireframes. Prototypes can be generated from requirements outputs, such as translating scenarios into storyboards or use cases into card-based models, and experience maps or customer journey maps are used to visualize the user’s end-to-end experience. The final stage, construction, is facilitated by tools like physical computing kits (such as Arduino, LilyPad, and MaKey MaKey), which are crucial for building electronic devices and are deeply connected to the maker movement. Additionally, Software Development Kits (SDKs) provide comprehensive packages of programming tools, components, documentation, and APIs (Application Programming Interfaces) necessary for platform-specific application development.