Understanding usability allows us to provide insights into whether a system may be used effectively and efficiently. It can also consider a user’s satisfaction or comfort with using a system, and whether a system can be used safely (minimising or trapping errors when interacting with the system). Usability analysis helps designers to improve the usability of a system, to support effective and efficient performance, and user acceptance.
What is it?
Usability analysis can focus on whether users are able to perform tasks effectively when using a system, and/or how easily the tasks can be performed. In essence, usability refers to how ‘user-friendly’ a product or system is. Core methods used in usability analysis include:
- Heuristic review (analyst assesses the system’s conformance to a checklist of usability principles and user requirements)
- Surveying (to measure users’ reactions and responses to a system)
- Experimental testing (measuring users’ performance while interacting with the system under controlled conditions)
To collect these measurements, we analyse human inputs (e.g. auditory and visual), outputs (e.g. motor skills), and cognitions (e.g. decisions, motivation) while using a task or system. Performance can be measured on a single task or system, or can be used to compare different design options to analyse the differences. Testing can be done online, in an office environment, in a mock-up or simulated environment, or in the actual working environment.
Fidelity and timing
Usability testing can occur in either high fidelity (e.g. fully-immersive, complete replica simulator or actual working environment) or low fidelity (paper-based prototype or simple electronic prototype) situations. Low-fidelity testing is often done early in the design process, to provide as much information as possible prior to investing time and money into more realistic prototypes. High-fidelity testing is typically done later in the design process. Factors to consider in determining appropriate fidelity levels include the cost of constructing high-fidelity testing environments and the type of information that the design team would like to gain from the test. These factors help us determine what type of testing will provide the best value and highest quality outcomes.
Participants for usability tests are chosen using ‘user profiles’; that is, if the end-users have certain characteristics that do not appear frequently in the general population, we will need to select participants specifically. We are mindful to identify characteristics of the end user, not just the purchaser, because sometimes these groups do not overlap in their characteristics and requirements.
Pilot testing is an option that takes place prior to a full-scale test. This is to ensure that any unforeseen factors (e.g. software bugs, distracting sights/sounds in the testing room) do not affect the actual test results. Ensuring that these issues are accounted for before a full-scale test can save time and financial resources.
After user testing and analysis takes place, we provide a report summarising the analysis results and suggested interventions. While making recommendations we carefully consider and provide advice regarding design or engineering trade-offs; and considering these tradeoffs, will make recommendations that allow the user to achieve the best performance across the entire system.