Methodologies for Measuring Usability

In the previous article we talked about User-Centered Design and how the knowledge of the user and the context in which he interacts with a system is essential to develop successful interfaces. We are now going to talk about a set of methodologies that allow us to optimize the answers we give to users' needs in certain contexts of use. As mentioned (Rubin, J., Chisnell, D., 2008) “ UCD [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 during a product's development lifecycle .”

These techniques are:

• Ethnographic research: observation in the place where the product will be used.
  
• Participatory Design: involvement of users and stakeholders in product design.
  
• Focus group design: can be used in the preliminary phases of the project to evaluate preliminary concepts with potential users.
  
• Surveys: allow you to gauge the preferences of a broad base of potential users.
  
• Demonstration (exploratory): once we have an idea of ​​who our target is and their goals and tasks, demonstrations can be used to explore how the user relates to and uses the product through a first concept.
• Card Sorting (open and closed): is very useful for designing the “findability” of content or functionality.
• Paper Prototyping: Users are shown some aspect of the product on paper, then asked questions about it or asking about other avenues.
• Heuristic or expert assessments: Expert assessments involve an evaluation of the product or system, typically by a  usability expert or human factors expert with little involvement with the project.
• Tthis usability: (the focus of this book) the application of techniques to collect data while observing potential users using the product while performing tasks in a realistic way. This type of testing can be divided into two main approaches:
  
  • the first involves formal tests conducted as actual experiments with the aim of confirming or disproving certain hypotheses;
  • the second, less formal but still rigorous, employs an iterative cycle of tests aimed at exposing usability deficiencies and gradually shaping the product under study.

• Follow-up studies: take place after the formal presentation of the product. The objective is to capture data for the next versions of the product.