Choosing a platform is one of the first real design decisions you make in an HCI project, and it constrains almost everything that follows: screen size and input method, interaction patterns, offline behavior, accessibility options, distribution, and even how users discover your app. In this topic we treat platform selection as a structured decision rather than a preference. You weigh who your users are and where they will realistically use the product, what capabilities the interface actually requires (camera, sensors, notifications, large-screen multitasking, keyboard-heavy entry), what your team can actually build with the tools and time available, and then you write the decision down with the reasoning behind it.
That last step matters more than students expect. A platform choice that is documented with criteria, alternatives considered, and trade-offs accepted can be defended to a client or instructor, revisited when requirements change, and reused as input to your scope document. An undocumented choice usually turns into an argument later in the term.
The videos below come from software architecture and system design rather than from HCI directly. Watch them for the decision-making method, not for the specific technologies: notice how each one starts from requirements and constraints, lays out options, names the trade-offs, and arrives at a justified choice. Then practice translating that same discipline to your own question — mobile, web, or desktop — where the constraints are users, context of use, and interface capability instead of servers and databases.
These videos were chosen from YouTube on October 3, 2026. Each has captions; the player turns them on. Videos on YouTube can be changed or removed — if one no longer plays, tell your instructor. If a player does not appear, use its Watch on YouTube link.