Task Four: Discussion of test design factors.
(Nielson, 1993) usability testing results in the identification of mistakes that users make while using an interface. Many of today’s computer systems and websites are a user-centered design for that same reason as feedback from users is irreplaceable.
(Lazar, 2001) during testing, invigilators are unwilling to give frequent or in-depth help as participants are expected to use the technology to get assistance. In performing usability testing, selecting a target user population truly representative of the user population must be accomplished.
Discussion about issues in task set design;
(Nigel Bevan and Miles Macleod, 1994) describes usability testing as an effective way to understand how real users experience the website or application.
(Jason, 2014) to design an effective usability test, it is important to identify where the test will take place, when it will be scheduled, what the tests will be entailing and who the target audience will be. The target audience will consist of one or more user groups. Each user group should be given tasks to perform during testing that reflect their different usage patterns. Here are some factors to consider while designing effective tasks for user.
• Making the Task Actionable
Having users talk through what they would do allows invigilators to observe the ease or frus-tration that comes with using the interface.
• Making the Task Realistic
Poorly written tasks make it more difficult for participants to undertake to process of doing the task.
• Avoiding Giving Clues and Describing the Steps
Step descriptions often contain hidden clues as to how to use the interface. Task scenarios that include terms used in the interface also bias the users.
Discussion about issues in Usability measure selection.
(Nielson, 2001) It is easy to specify usability metrics, but hard to collect them. Usually, usability is measured relative to users’ performance on a given set of test tasks. The most basic measures are based on the definition of usability as a quality metric:
• success rate (whether users can perform the task at all),
• the time a task requires, efficiency
• the error rate,
• Users’ subjective satisfaction/post hoc.
• Cognitive measures (think aloud protocols)
Discussion about the use of think-aloud protocols.
(Nielsen, 2012) thinking aloud is an effective usability method. In a thinking aloud test, test participants are asked to use the system while continuously thinking out loud that is, simply verbalizing their thoughts as they move through the user interface.
(Vivienne Trulock, 2008) suggests that thinking aloud allows invigilators to understand how the user approaches the interface in the lab and what considerations the user keeps in mind when using the interface.
(Erica Olmsted-Hawala, 2010) two of the most common thinking aloud protocols that usability practitioners engage in are:
• Concurrent TA-where the participant is encouraged to “think out loud” while working on a task.
• Retrospective TA-where the participant talks only after the session is completed, typically while watching a video of his or her session
Discussion about test procedure issues;
(Damian Rodrigues, 2011) Procedures are essential to accomplish a task or process. They show how a task or process is supposed to be completed. Procedures are action oriented. They determine steps to take, and the order in which they need to be followed. They are often instructional. Well-written procedures are normally solid, precise, factual, short, and to the point.
Procedures should communicate what readers need to know, not just what they want to know. They might need to know how to do the process correctly, faster, or with less waste.
Step One: Gather Information
Gathering detailed information is essential on the process through interaction with people who hold key information from which a procedure will be accomplished.
Below are some steps to design an effective set of tasks for the users.
Step Two: Start Writing
Writing actions following the order in which they happen. Starting with the first action, and end with the last action.
Avoiding too many words and being specific enough to communicate.
Step Three: Assessing Design Elements
Flowchart -This shows a process as a diagram. Using a series of symbols and arrows to indicate flow and action of a process which makes it easy to follow.
Discussion about the number of test participants a test should use.
Usability evaluations come in different forms such as heuristic evaluation, cognitive walkthroughs with a single user or group cognitive evaluations there are always discussions regarding how many users are enough for a test.
(Virzi, 1992) suggests that five users will uncover approximately 80% of usability problems. A study by (Nielson, 1995) further suggests that five users are enough.
Research by (Faulkner, 2003) suggests that as many as 85% of usability problems but that as few as 55% could be found as well with using only five users.
(Nielsen, 1995) With increasing the number of users to 15, the range of problems found can be 90-97%. Heuristics are rules of thumb or design guidelines to incorporate in the design of products. Is known for his ten usability heuristics, which are ten general principles for website design.