Testing Methods for Usability
There are three types of analytical testing methods that can be mixed or matched in the testing process, and they can include both analytical and empirical evaluations. The three types that are most commonly used are:
- Inspection methods that tend to focus on the causes of good or poor usability.
- System–centered inspection methods that focus solely on software and hardware features regarding attributes that either promote or obstruct usability.
- Interaction–centered methods that focus on two or more causal factors such as software features, user characteristics, task demands, or other contextual factors.
Empirical evaluation methods focus on evidence of good or poor usability such as the positive or negative effects of attributes of software, hardware, user capabilities and usage environments. User-testing is the principal project-focused method and uses project-specific resources such as test tasks, users, and measuring instruments to expose usability issues that may present themselves during use. Empirical methods can also be used to demonstrate superior usability or to optimize tuning parameters for animations and other interface components.
Focus groups may also provide valuable information about attitudes, beliefs, desires, and reactions to concepts or processes.
Remote testing allows testers to conduct research with participants in their natural environments by employing screen-sharing software or online remote vendor services.
Field testing can be a means to collect data about users, user needs, and product requirements through observation and interviews. This type of testing can collect information about task flows, inefficiencies, as well as the organizational and physical environments of the users.
Moderating Techniques for Usability
There are four common moderating techniques used for usability testing depending on the goals of each session. They include:
- Concurrent Think Aloud (CTA) — Used to understand participant’s thoughts as they interact with a product by having them think aloud as they work.
- Retrospective Think Aloud (RTA) — Used to retrace the participant’s steps when the session is completed. This may include eye-movement evaluation to determine visual placement components of the product.
- Concurrent Probing (CP) — Used to ask follow-up questions when the participants say or do something interesting during testing.
- Retrospective Probing (RP) — Used to ask about the participant’s thoughts and actions after testing is completed.
Each test contains valuable information for specific situations, and each type of technique has benefits and detriments. Heuristic surveys also provide valuable information and are easily constructed using a Likert scale to rate tasks and functions on a scale of 1 to 5, or a Strongly Agree to Strongly Disagree metric.