Task analysis is the systematic study of what users actually do to accomplish a goal. Instead of guessing at features, you observe or interview people, then break their work into a structured set of steps, decisions, and sub-goals. The result is a task model: a description of the user's goal, the sequence of actions needed to reach it, the information required at each step, and the conditions under which the sequence changes.
In this module, task analysis is the bridge between raw requirements-gathering data and the use case scenarios you will write. Hierarchical Task Analysis (HTA) decomposes a goal into numbered sub-tasks and plans, giving you a tree you can read almost directly into main flows and alternate flows. Cognitive task analysis goes after the invisible part — what the user must know, remember, notice, or decide — which is where most interface difficulty actually lives. Once you have a model, you validate it by walking users back through it and correcting the steps you got wrong.
The three videos below approach the topic from different directions: one on task analysis as a decomposition and teaching technique, one on cognitive walkthrough as a way to evaluate a task step-by-step from the user's mental perspective, and one on hierarchical breakdown structures from project management. While watching, focus on the mechanics: how a goal is split, how deep the decomposition goes, how steps are numbered and ordered, and how you would know whether the resulting model is correct. Note also where each technique stops — none of these videos is a complete HCI task-analysis method on its own, so read them as complementary pieces.
This video, from the Center for Community Engagement, introduces task analysis as a method for breaking a task into its component steps so that a person can be supported in performing it independently. It is framed around executive functioning and student independence rather than software design, so expect examples drawn from everyday and instructional tasks. Likely coverage includes how to identify the goal, how to list and sequence the steps, and how to judge the right level of detail.
It gives a clear, slow-paced explanation of the core decomposition skill at the heart of this topic — identifying a goal and listing its steps — which transfers directly to interface tasks even though the examples are not from computing.
The Nielsen Norman Group explains the cognitive walkthrough, a task-based inspection technique in which evaluators step through a task as a first-time user would and ask, at each step, whether the user would know what to do and whether they would recognize that their action moved them toward the goal. The video covers what the method evaluates (learnability), how the task steps are defined in advance, and how findings are recorded.
NNgroup is a widely cited authority in usability, and this video connects directly to the cognitive side of task analysis and to validating a task model by walking it step by step from the user's point of view.
This short video contrasts the Work Breakdown Structure with product, resource, and organizational breakdown structures, explaining what each one decomposes and how the hierarchies are built and numbered. It comes from project management practice rather than HCI, but the underlying logic of parent nodes, child nodes, and levels of decomposition is the same structure used in Hierarchical Task Analysis.
It is a compact, concrete model of hierarchical decomposition and numbering conventions, which helps you see how an HTA diagram is constructed and why keeping different kinds of breakdowns (tasks versus deliverables versus roles) separate matters when you write use cases.
Together these videos support the module outcomes by supplying the analysis step that sits between data collection and specification. The task analysis video and the breakdown structure video give you techniques for decomposing user goals into ordered, numbered steps, which is the raw material for composing accurate use case scenarios with main and alternate flows (MO1). The cognitive walkthrough video shows how to use structured observation and step-by-step questioning to surface what users need to know and do, reinforcing observation as a requirements-gathering technique and offering a way to validate task models with real users (MO2). Finally, the habit of separating what a step does from what it requires and how well it must perform helps you sort the findings into functional and non-functional interface requirements (MO3).
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.