BIDH5000 Chap.2 Human-Centred Design and Usability
Human-Centred Design and Usability
Human-centred design uses inquiry, synthesis, prototyping and evaluation to learn what people need and how a service fits real work. This chapter distinguishes observations from interpretations, treats personas as evidence-based patterns rather than fictional averages, and separates usability from the wider user experience.
It also shows how formative evaluation explains failure during development while summative evaluation estimates performance after a concept stabilises. Inquiry begins with recent behaviour in context. Ask participants to reconstruct a real episode, including what triggered the task, what information was available, where they paused and how they adapted. Observation can then compare reported work with work as performed.
The aim is not to catch inconsistency but to discover the informal practices that keep care functioning. Synthesis should keep observations, interpretations, implications and tests separate. A vivid quotation is not automatically a general requirement, and an average persona can erase the variation that matters most for access. Retain disconfirming cases and show which users and settings support each inference.
Prototype only enough to answer the next decision. Early artefacts can test language, sequence and responsibility without implying that the whole service is ready. Evaluate usability through task success, error quality, effort, time, recovery and satisfaction for specified users, goals and contexts. Evaluate user experience more broadly through expectations, feelings, beliefs and meaning before, during and after use.
Formative evidence should explain why the concept fails and guide revision. Summative evidence belongs later, when the intervention and workflow are stable enough for a performance comparison. Throughout the design process, record trade-offs. A change that simplifies one role may transfer work to another, and personalisation may increase both relevance and data exposure.
Make the choice, evidence, safeguard and reopening condition visible.
What this chapter covers
- 01
Contextual inquiry and recent episodes
- 02
Interviews, observation and focus groups
- 03
Synthesis, personas and disconfirming cases
- 04
Iterative prototypes as learning devices
- 05
Effectiveness, efficiency and satisfaction
- 06
Formative and summative evaluation
Evaluate a referral-review prototype
- 2Define realistic tasks, contexts and participant variation relevant to access and use.
- 2Select formative measures that reveal errors, expectations and reasons for difficulty.
- 2Explain when a later comparison can estimate real-world performance and balancing effects.
Key terms
- User experience
- Perceptions and responses associated with use or anticipated use before, during and after interaction.
- Usability
- Effectiveness, efficiency and satisfaction for specified users, goals and contexts.
- Contextual inquiry
- Study of people carrying out real work in context, often combining observation with targeted questions.
- Persona
- A research-grounded pattern of goals, constraints and behaviour used to support design decisions.
- Formative evaluation
- Evaluation during development that explains problems and guides revision.
- Summative evaluation
- Evaluation of sufficiently stable work that estimates performance or outcomes.
Human-Centred Design and Usability FAQ
What is the strongest opening question in user research?
Ask a participant to reconstruct a recent relevant episode. Follow the trigger, information available, actions, pauses, workarounds and consequences. This produces behavioural and contextual evidence instead of a speculative opinion about a future tool.
How are usability and user experience different?
Usability focuses on effective, efficient and satisfactory task achievement in context. User experience is wider and includes emotions, beliefs and meaning across time. A useful system can perform well on one dimension and poorly on the other.
When should formative evaluation stop?
It should continue until major interaction and workflow uncertainties are sufficiently resolved for the next decision. The transition to summative evaluation is justified by design stability and the need to estimate performance, not by a fixed number of sessions.
Why can a polished prototype still be weak evidence?
Visual finish does not establish fit, safety or effectiveness. A prototype is valuable when it exposes assumptions, supports realistic tasks and produces learning that changes the design. Evidence comes from the evaluation, not appearance alone.
Assessment move
Build a compact research plan for the same project used in Chapter One. Write one recent-episode interview prompt, one observation aim and one disconfirming case you need to seek. Separate every note into observation, interpretation, implication and test. Define one effectiveness, efficiency and satisfaction measure for a realistic task.
Finish by stating which question is formative and which later question requires a stable intervention and real workflow. Practise converting speculative questions into behavioural prompts, then explain what decision each answer could change. Create two contrasting user patterns grounded in constraints and goals, and test whether the proposed concept unfairly treats either as an exception.
Run a paper-prototype session in which you record expectations before each action and recovery after each error. Close by listing the trade-offs that remain unresolved and the next smallest prototype capable of producing useful evidence. Review the sample after each round and ask whose context is still missing; add a targeted participant or alternative method instead of claiming that repetition has proven universality.
