Throughout this course you have made dozens of design decisions: where to put a button, how to label it, what feedback to show after a click. This topic asks you to look back at those decisions and name the theory behind them. Concepts such as affordances, the human-computer interaction cycle, and direct manipulation are not just vocabulary for an exam — they are the reasoning you use to explain why an interface works, and the evidence you cite when someone challenges your design.
Connecting theory to outcomes runs in two directions. Forward, theory guides choices before you build: a model of how users perceive, act, and interpret feedback tells you what to prototype in the first place. Backward, theory gives you a yardstick for evaluation: you can inspect your finished product and ask whether its controls actually signal their use, whether feedback closes the loop of interaction, and whether users manipulate meaningful objects or wrestle with hidden commands.
The three short videos below revisit core concepts at a practical level. As you watch, keep your own project on screen or in mind. For each idea presented, try to find one place in your interface where you applied it well, and one place where you did not — those paired examples are exactly the material you need for your final reflection, your design rationale presentation, and your list of proposed improvements.
A short explainer on affordances, one of the foundational concepts in interaction design, illustrated with a concrete example. Based on its title and description, it defines what an affordance is, distinguishes perceived cues from actual possible actions, and shows how affordances contribute to apps that feel intuitive and effective.
Affordances are among the most frequently invoked theories when designers justify control styling, button shapes, and clickability cues, making this a direct bridge from concept to design decision. The Interaction Design Foundation is a well-established HCI education provider, and the compact format suits a review before you audit your own interface.
This video presents the cycle of interaction between humans and computers — the loop in which a user forms a goal, acts on the interface, and interprets the system's response. Its description frames this understanding as essential groundwork for designing effective user interfaces and experiences, so expect coverage of the stages of that loop and why each one matters.
The interaction cycle is the framework that lets you explain feedback, visibility of system status, and error recovery in your final product rather than describing them as isolated features. It maps cleanly onto the subtopic of moving from concepts to real-world application, giving you a structure for walking an audience through a user's path in your interface.
NNgroup introduces direct manipulation as an interaction technique in graphical interfaces where users act on visible representations of objects rather than issuing abstract commands. The video is likely to define the technique, show examples such as dragging and resizing objects, and discuss when this style of interaction helps or hinders users.
Direct manipulation is a classic HCI principle with clear trade-offs, so it is a strong test case for evaluating how closely your final product aligns with established theory. Nielsen Norman Group is a widely cited usability research organization, which makes this a defensible source to reference in a design rationale.
These videos supply the theoretical vocabulary you need for the module's evaluation and reflection work. Affordances and the interaction cycle give you specific criteria for inspecting your finished interface against usability benchmarks and original requirements (MO1), and they give you named, citable concepts for defending design choices when you present your rationale (MO2). Revisiting direct manipulation and the perception-action-feedback loop prompts a sharper critique of your own process, including where psychological and accessibility considerations were handled well or overlooked (MO3). Finally, any gap you find between what theory recommends and what your product delivers becomes a concrete, well-justified candidate for your list of future improvements (MO4).
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.