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).
Part B case study (Questions 10–14, as printed on page 5 of the paper). Medic123 is a large supplier of medical equipment to many hospitals in Canada. One of their most popular products is a new ambulatory smart infusion pump. One of the innovative concepts in the design of the pump is a drug library. The drug library contains a repository (database) of drugs available in a given unit of a hospital. Once the drug library is loaded into the pump, hospital staff (i.e., nurses and anaesthesiologists) can program the pump to have it deliver (infuse) a specific quantity of a drug at precise time intervals. Preliminary usability testing of the pump reveals a diminution of programming errors when compared to other existing pumps as well as a very positive user experience (reported by participants through subjective measures).
To upload the drug libraries to the pumps, Medic123 will rely on a computer software. The software will run under the Windows operating system and will be provided to hospitals purchasing the new ambulatory smart infusion pump. Hospital pharmacists are the intended users of the software. Using the application, they will be able to upload drug libraries to the pumps used throughout their hospital.
Different drug libraries can be configured for different area of the same hospital (for example, a drug library for the pumps in the maternity unit and a drug library for the pumps in the intensive care unit). The software will allow pharmacists to perform a variety of tasks related setting up smart infusion pumps drug libraries. For example typical functionalities of the software will include (but not limited to): building the drug libraries, set the upper and lower limits for each drug in the library, set the minimum and maximum time intervals for drug delivery, and logically organize the drug libraries in accordance the different units and departments of a hospital. Pharmacists are expected to update and upload drug libraries to the pumps once or twice a year.
Since Medic123 does not have any expertise in designing Windows-based computer software, it has contracted MedicSoft, a software engineering company specializing in medical software, to conceive, design, and test the application. You are the user interface designer for MedicSoft and have been assigned to this project. Your task is to design the user interface and user experience for the software following a User-Centered Design approach. MAKE WHATEVER ASSUMPTIONS YOU NEED TO CONSTRUCT POSSIBLE ANSWERS. Clearly state your assumptions.
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.
1. Effectiveness (task completion, especially error-free completion). The drug-library editor must let pharmacists build, edit and publish libraries that fully and correctly capture the intended drugs, concentrations, and dosing limits, with essentially zero tolerance for a limit being silently entered wrong. This is the most important goal here because the software's downstream effect — the safe dosing limits programmed into every pump in a hospital unit — is directly safety-critical; an "effective but slow" tool is acceptable, an "efficient but error-prone" one is not.
2. Learnability (ease of first-time and infrequent use). Given the case study states pharmacists update and upload libraries only once or twice a year, the software will almost always be used by someone who does not remember the details of the last session. The interface must therefore be learnable essentially from scratch each time — clear labelling, visible affordances, minimal reliance on memorised shortcuts — because a design that is efficient for a daily power user but has a steep learning curve is actively unsuitable for this infrequent-use pattern, and re-learning errors carry the same safety consequence as any other data-entry error.
3. Safety (error prevention and graceful error recovery). Beyond simply "being usable," the software must actively prevent dangerous states from being reachable — e.g. refusing to let a pharmacist save a dosing limit outside a clinically sane range without an explicit, deliberate override — and must make any error easy to notice and to correct before it is uploaded to a pump. This is important because in a safety-critical medical-device workflow, the cost of an undetected error is not user frustration but patient harm, so error prevention and recoverability outrank pure efficiency as design priorities.
