Managing Partner YouX
Managing Partner iBloom
In the previous article we talked about User-Centered Design and how knowledge of the user and the context in which they interact with a system is essential to developing successful interfaces. Let's now talk about a set of methodologies that allow us to optimize the responses we give to users' needs in certain contexts of use. As mentioned by (Rubin, J., Chisnell, D., 2008) “ UCD [User Centered Design, or User-Centered Design] comprises a variety of techniques, methods, and practices, each applied at different points in the product development lifecycle. Reviewing the major methods will help to provide some context for usability testing, which itself is one of these techniques. Please note that the order in which the techniques are described is more or less the order in which they would be employed during a product's development lifecycle .”
These techniques are:
For a team that has implemented User-Centered Design, measuring usability is important from the outset so that the entire multi-disciplinary team involved in the project understands the objectives and goals to be achieved. The ISO/IEC 9126-6 standard (now replaced by ISO/IEC 25010:2011 ) defines the effectiveness, efficiency and satisfaction requirements that an interface must have so that the user can achieve their objectives.
Objective: evaluate whether the user was able to successfully complete a task.
We could thus measure effectiveness using the following general formula:
Which we could multiply into success rate without errors, success rate with errors and success rate without critical errors.
Example:
Total tasks successfully completed = 7 Total number of tasks = 10
Effectiveness = 7/10 x 100% = 70%
Objective: evaluate how much time the user needs to complete the task.
• Task execution time: amount of time the user needs to complete a task. In operational terms, the values of the various users are added together and an average is calculated. Example:
Task execution time 13”+10”+7”+10” = 40 seconds
Average = 10 sec.
• Task completion time compared to that of a heavy user : this is a lesser-known metric that aims to see how intuitive the flow is for people with less technological proficiency.
After completing a task, even if it was not completed successfully, users must complete a questionnaire that measures the degree of difficulty of the task. The most popular:
• ASQ: After Scenario Questionnaire.
• NASA-TLX: The NASA Task Load Index, which is a measure of mental effort.
• SMEQ: subjective mental effort questionnaire.
• UME: usability magnitude estimate.
• SEQ: single ease question : this is a good alternative because it is simple. Something like, “Overall, how difficult or easy was this task to accomplish?
“Very difficult – 1 to 7 – Very easy.”
It serves to understand users' perception of what was tested. At the end of the test, a questionnaire is administered to determine the user's level of satisfaction with the test as a whole. Most used questionnaires:
References:
Rubin, J., & Chisnell, D. (2008). Handbook of usability testing: how to plan, design, and conduct effective tests (2nd ed.). Indianapolis: Wiley.
YouX is a software development company focused on providing the best user experiences.
Sede: Av. da Peregrinação, 9, 1 dto – 1990-425 Lisboa
Info@you-x.eu – Telefone: +351 211 353 284
Digital Strategy
UX Design
UI Design
Digital Sprints
User Research
AR applications
WebAR
UX Audits
Software development
Mobile Applications
Web Apps
© 2021-25 Xperialab Lda ® Todos os direitos reservados.
YouX is a software development company focused on providing the best user experiences.
Digital Strategy
UX Design
UI Design
Digital Sprints
User Research
AR applications
Web AR
Software development
Mobile Applications / Web Apps
Websites
© 2021/5 Xperialab Lda ®
Todos os direitos reservados.
You cannot copy content of this page