19-Soft-B2 User Interface · May 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams, May 2014 — 04-Soft-B2, User Interface (closed book, 3 hours). Part A: answer any FIVE of the NINE questions (10 marks each); Part B: answer ALL FIVE questions (10 marks each), all based on the same case study — Medic123's ambulatory smart infusion pump and its Windows drug-library upload software, designed by MedicSoft using a User-Centered Design (UCD) approach for hospital pharmacists. Most questions call for essay-format answers; clarity and organisation count. This solution answers all fourteen questions as a full study resource.
Reference texts. Rogers, Sharp & Preece, Interaction Design: Beyond Human-Computer Interaction, 5th ed., Ch. 1–3 (interaction design, cognitive aspects, mental models), Ch. 9–10 (prototyping, personas), Ch. 11–12 (data gathering, requirements), Ch. 15–16 (evaluation, lab vs. field studies); Nielsen, Usability Engineering, Ch. 4–6 (usability heuristics, iterative design, usability testing); Shneiderman, Designing the User Interface, 6th ed., Ch. 2 (guidelines, principles), Ch. 12 (internationalization); Norman, The Design of Everyday Things, Ch. 1–4 (visibility, affordances, feedback, conceptual models).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
A laboratory study evaluates the interface in a controlled setting (a usability lab or a quiet meeting room), with a moderator present, a fixed set of pre-defined tasks, and controlled conditions (equipment, lighting, absence of interruption); participants are typically observed directly, sometimes recorded, and often asked to think aloud. A field study evaluates the interface in the participant's own real working environment (here, the actual hospital pharmacy or nursing unit), during real or realistic work, with the natural interruptions, noise, time pressure and coexisting tasks of that environment left in place rather than controlled away.
Pros of laboratory studies: high internal control means confounding variables are minimised, so differences in performance can more confidently be attributed to the interface itself; equipment (screen/eye/click recording) is easier to set up and more reliable; and sessions are faster and cheaper to run, schedule and repeat. Cons: the artificial setting risks low ecological validity — a pharmacist calmly performing a scripted task in a quiet room may behave quite differently than one programming a library between other duties, with a colleague talking and an unrelated alarm sounding, so lab results can understate real-world error rates and time pressure. Pros of field studies: high ecological validity — the evaluation captures the real context of use, including interruptions, multitasking and environmental factors that are exactly the conditions the system must actually be safe and usable under; and it can surface workflow and organisational issues (how the software fits, or fails to fit, around existing pharmacy procedures) that a lab task list would never reveal. Cons: far less control — confounding variables (a busy shift vs. a quiet one) make it harder to attribute observed problems specifically to the interface; data collection is more difficult (recording equipment is harder to deploy discreetly in a working hospital unit) and observations are less directly comparable across participants; and access/scheduling in a live clinical setting is harder and more disruptive to arrange than a lab session.
In practice, the two are complementary rather than competing: lab studies are well suited to early- and mid-iteration diagnostic testing of specific interactions (fast, cheap, controlled), while a field study close to release is valuable for validating that the design actually holds up under the real conditions, interruptions and workflow of a hospital pharmacy.
