HCI Finals (Part 1)

• Usability is the extent to which a product can be used by specified users to achieve specific goals with effectiveness, efficiency, and satisfaction in a specified context of use.
• Usability involves incorporating user feedback throughout product development to minimize costs and effectively meet user needs.
• Usability ensures that products can be used easily by individuals of any skill level, preventing excessive frustration and enhancing user experience.
• ISO 9241-11 Definition: Usability is the extent to which a product can be used by specified users to achieve specific goals with effectiveness, efficiency, and satisfaction in a specified context of use.
• Usability Professionals Association Definition: Usability involves incorporating user feedback throughout product development to minimize costs and effectively meet user needs.
• Steve Krug's Definition: Usability ensures that products can be used easily by individuals of any skill level, preventing excessive frustration and enhancing user experience.
• Common Themes in Usability Definitions:

  1. User Involvement
  2. Activity
  3. Interaction with a Product/System
• User Involvement: All definitions emphasize the user as the central focus of interaction.
• User Involvement: Usability is assessed based on the user's experiences and needs.
• Activity: Usability concerns the user actively engaging with a product or system to perform tasks.
• Interaction with a Product/System: Usability evaluations consider how users interact with a product, system, or service, focusing on the ease and quality of this interaction to achieve desired outcomes.
• Usability: Focuses on the user's ability to successfully use a product or system to perform specific tasks.
• Usability: Measures effectiveness, efficiency, and satisfaction in a particular context.
• User Experience: Encompasses the full range of interactions a user has with a product or system.
• User Experience: Includes the user’s thoughts, feelings, and perceptions that arise from these interactions.
• User Experience: Concerns the overall quality of the user's encounter beyond mere functionality.
• Usability metrics are tools used to assess and quantify various aspects of how users interact with a product or system.
• Usability metrics are critical in determining the usability of a product and improving user experience.
• Metrics: These are measures used to evaluate specific phenomena or attributes.
• In the context of usability, metrics should be both observable and quantifiable, allowing for objective assessment of a product's user interface.
• Purpose of Usability Metrics:

  ● Reveal User Experience

  ● Measure Interaction Quality
• Reveal User Experience: They provide insights into the user's overall experience by examining the interaction between the user and the product.
• Measure Interaction Quality: Metrics evaluate how well users can interact with a product to perform tasks.
• Key Usability Metrics:

  1. Effectiveness
  2. Efficiency
  3. Satisfaction
• Effectiveness: This metric gauges the ability of users to complete tasks using the product.
• Effectiveness: It typically involves measuring the accuracy and completeness with which users achieve their goals.
• Efficiency: This measures the resources expended by users to achieve their goals, such as time or the number of steps required to complete a task.
• Satisfaction: This assesses how pleased users are with their interactions with the product.
• Satisfaction: It is often evaluated through surveys and feedback to gauge users’ feelings and attitudes toward the product.
• Behavioral and Attitudinal Measurements: Usability metrics also consider user behaviors (what users do) and attitudes (what users feel), providing a comprehensive view of the user experience.
• Metrics are measured in the context of a task.
• When designing a usability study, it's important to clarify your objectives and decide whether the study will be formative or summative.
• Formative or summative studies differ in focus and timing within the product development cycle, but both are essential to creating a user-centered product that meets or exceeds user expectations.
• Formative: Conducted during the development process to improve the product based on feedback.
• Formative: The focus is on identifying and solving usability issues.
• Summative: Conducted after the product development is completed to assess the quality of the user experience and measure the product's usability against predefined criteria or competitors.
• Formative Studies:

  What aspects of the product work well for users?
• Formative Studies:

  What do users find frustrating?
• Formative Studies:

  What are the most common errors or mistakes that users commit?
• Summative Studies:

  Did we meet the usability goals of the product?