第9章ソフトウェア工学

Also called user acceptance testing, acceptance testing is the process used to determine whether the software solution fulfills the customer’s expectations. This level of testing generally occurs after system testing and is done by the customer, client, or other end user of the software.

Acceptance tests are formalized testing that can be specified by the customer, and it tests both functional and nonfunctional requirements. To test functional requirements, acceptance tests often follow scenarios created in requirements analysis. For example, in a library information system, we can use scenario “Add new book” to create an acceptance test. During the acceptance test, the tester will fill out an input form, submit it, and check that the system contains a new book.

In the automotive industry, acceptance testing could be done by the department that requested the new features. It could also be done by dealerships or customers who own or have purchased previous versions of a given automobile. A driver could be asked to use the new features and then be surveyed to see what issues occurred.

The user-centered testing method that evaluates how easy and intuitive a software system is to use is called usability testing. It goes beyond just ensuring the software functions correctly and focuses on the user interface/user experience (UI/UX) the part of computer programming that concerns how information is presented to the user and how the user can interact with a program. Usability testing is essential because software that is difficult to use can frustrate users and hinder adoption. By identifying usability issues early in the development process, developers can make improvements that lead to a more user-friendly and successful product. Usability testing typically involves recruiting a small group of users representative of the target audience. These users are asked to complete a series of tasks while a usability tester observes their actions and records their feedback. The tester pays close attention to areas such as:

• Task completion: Can users complete the intended tasks efficiently and without errors?

• Ease of learning: How easy is it for users to learn how to use the software?

• User satisfaction: Are users satisfied with the overall user experience?

While acceptance testing generally happens near the end of a project, usability testing can and should happen much earlier. The focus of usability testing is to enhance user experience, and it typically emphasizes the following areas:

• Interactivity: Are interaction mechanisms (e.g., menus, buttons) clear and consistent? Do they provide appropriate feedback to user actions?

• Layout: Is information organized in a logical and easy-to-find way? Can users navigate the system intuitively?

• Readability: Is text easy to read and understand? Are error messages clear and actionable?

• Aesthetics: Is the overall look and feel of the software pleasing and consistent? Do colors, fonts, and images contribute to usability?

• Display usage: Does the software solution use the best possible screen size and display resolution?

• Timing: Are important features and other pieces of functionality quickly accessible?

• Feedback support: Is useful feedback provided to end users, and can they easily go back to their work once the feedback has been read?

• Personalization: Is the application addressing various categories of users and does it support inclusion?

• Help: Is it easy for users to access help and other support options?

• Accessibility: Can the software be used by people with disabilities? This includes features such as screen readers and keyboard navigation. Note that accessibility testing is a subset of usability testing that focuses specifically on the needs of users with disabilities. Here are some examples of accessibility considerations:

◦ Screen reader compatibility: Can screen readers interpret the content and functionality of the software accurately?

◦ Color contrast: Does the software use sufficient color contrast to be usable by people with visual impairments?

◦ Keyboard navigation: Can all features of the software be accessed using only the keyboard?

◦ Content features: Is blinking, scrolling, or auto content updating avoided to accommodate users with reading difficulties?