People make mistakes, and interactive systems are where many of those mistakes become visible. This topic looks at human error systematically: the difference between slips (doing the wrong thing while intending the right thing) and mistakes (intending the wrong thing in the first place), the conditions that make errors more likely, and the design choices that either invite or prevent them. A recurring theme is that error is rarely just "user fault" — poorly labelled controls, ambiguous feedback, and interfaces that conflict with a user's mental model all produce predictable, systematic failures.
The second half of the topic turns to learning and recovery. Good interfaces are forgiving: they constrain dangerous actions, make the current state visible, offer undo, and explain problems in language the user can act on. They also support a learning curve, letting novices succeed through guidance and discoverability while giving experts faster paths. These goals sometimes pull against each other, which is why designers need principles rather than one-size-fits-all rules.
As you watch the three videos below, keep a running list of two things: (1) the specific error type or cause each example illustrates, and (2) the concrete design move used to prevent, contain, or recover from it. Pay attention to how error handling differs between a form on a large screen and an alert on a small mobile screen — the same principle often requires a different implementation.
An overview of what counts as "error" in human-computer interaction and how errors are classified, likely covering distinctions such as slips versus mistakes and the conditions under which each tends to occur. Expect definitions, examples from interactive systems, and discussion of why error classification matters for designers rather than being just academic labelling.
It directly addresses the foundational subtopics — types of human error and their causes — from the Interaction Design Foundation, a well-established HCI education producer, giving you shared vocabulary for the rest of the topic.
A practice-oriented talk on form design that focuses on preventing error messages before they happen, rather than writing better error text after the fact. It is likely to cover input formatting, labelling, validation timing, and other choices that reduce the chance a user enters something the system rejects.
Forms are the classic site of user error, so this video grounds the abstract idea of error prevention in concrete, reusable interface decisions you can apply in your own prototypes.
A short Nielsen Norman Group piece on how error alerts behave on mobile devices, arguing that modal dialogs for error messages often create usability problems on small screens. It discusses how error handling should respect the device context and the user's current task rather than interrupting it.
NNgroup is a leading usability research organisation, and this clip extends the topic into forgiving interfaces and error recovery while highlighting how platform context changes the right answer.
Together these videos support the module outcomes by making the link between user cognition and interface failure explicit. The first video supplies the error taxonomy needed to explain how a mismatch between a user's mental model and actual system behaviour produces systematic, repeatable errors rather than random ones (MO2), and connects to memory and attention limits that constrain what an interface can reasonably ask of users (MO1). The form-design and mobile-alert videos then translate that understanding into design practice — prevention, clear feedback, and recovery — giving you evaluable criteria to apply when critiquing a design (MO4) and concrete patterns to incorporate when you build your own low- to mid-fidelity prototype for a desktop or mobile context (MO5).
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.