Usability Score (SUS)

# Usability Score (SUS)

The Usability Score (SUS) is a standardized questionnaire that assesses a product's overall usability.

Variations and Adaptations

SUS is typically presented as a 10-item questionnaire, where users respond to statements on a 5-point Likert scale. While the standard format is widely used, teams may adapt the questionnaire by modifying the wording of the statements to better fit their specific context or audience. Additionally, some organizations may choose to complement SUS with qualitative feedback to gain deeper insights into user experiences. This combined approach can help teams identify specific usability issues and prioritize improvements.

Connection to Other UX Methods

SUS is often used alongside other usability testing methods, such as task analysis and heuristic evaluation. These methods provide a more comprehensive view of user interactions and can help identify areas for enhancement. By integrating SUS with usability testing, teams can track usability trends over time and measure the impact of design changes.

Practical Insights

Administer SUS after usability tests for immediate feedback.

Encourage a diverse participant pool to capture a range of experiences.

Analyze SUS scores in conjunction with qualitative data for richer insights.

Use SUS scores to benchmark usability against industry standards or competitors.

The Usability Score (SUS) helps measure a product's usability through user feedback.

Administer the SUS questionnaire to target users after they interact with the product.

Analyze the collected SUS data to identify usability strengths and weaknesses.

Compare SUS scores across different versions of the product to track improvements.

Share SUS results with stakeholders to inform design and development decisions.

Iterate on the product design based on insights gained from the SUS feedback.

The Usability Score (SUS) provides a reliable measure of a product's usability, helping teams make informed decisions that enhance user experience. By applying SUS correctly, users, teams, and businesses can achieve better alignment on usability goals and improve overall product effectiveness.

Facilitates clear communication about usability among stakeholders.

Enables data-driven decision-making for design improvements.

Identifies usability issues early in the development process, reducing risks.

Provides a standardized way to compare usability across different products or versions.

Enhances user satisfaction by focusing on user-centered design principles.

A product team is developing a new e-commerce app. The designer, Sarah, has created an intuitive layout, but the team is unsure if users will find it easy to navigate. To evaluate usability, the product manager, Tom, decides to implement the Usability Score (SUS) as part of their testing phase. He believes this standardized questionnaire will provide valuable insights into user experience.

During user testing, a researcher, Alex, observes participants as they complete key tasks in the app. After the testing sessions, Alex administers the SUS questionnaire to gather feedback on the app's usability. Participants respond to ten statements, rating their agreement on a scale from 1 to 5. Alex compiles the results, calculating the overall SUS score to assess how well the app meets usability standards.

With the SUS score in hand, the team convenes to discuss the findings. The score indicates that users find the app moderately usable, but specific feedback highlights issues with navigation. Armed with this information, Sarah iterates on the design, making adjustments to enhance user flow. The team plans another round of testing to see if the changes improve the SUS score, demonstrating their commitment to creating a user-friendly product.

The Usability Score (SUS) is most useful during product evaluations to assess user experience and identify areas for improvement. It provides a quantitative measure of usability that can inform design decisions.

Discovery: Conducting initial user research to understand usability expectations and benchmarks for similar products.

Design: Testing prototypes with users to gather feedback on usability before finalizing the design.

Delivery: Evaluating the usability of the product upon completion to ensure it meets user needs and expectations.

Optimisation: Analyzing usability scores post-launch to identify pain points and areas for enhancement in future iterations.

Comparative Analysis: Using SUS scores to compare usability across different versions of a product or against competitors.

Stakeholder Communication: Presenting SUS results to stakeholders to highlight usability strengths and weaknesses in a clear, quantifiable manner.

Teams can struggle with the Usability Score (SUS) due to misunderstandings about its purpose, the context in which it is applied, and how to interpret the results. Additionally, organizational constraints and data quality issues can complicate the use of the SUS effectively.

Misinterpretation of scores: Teams may misinterpret the SUS score as a definitive measure of usability.

Hint: Use the score as a directional indicator rather than a final judgment, and complement it with qualitative feedback.

Sample size limitations: A small number of responses can lead to unreliable scores.

Hint: Aim for a larger, more diverse sample to ensure the results are representative.

Contextual relevance: SUS may not capture usability nuances specific to certain products or user groups.

Hint: Supplement SUS with tailored usability tests that address specific user needs and contexts.

Survey fatigue: Participants may rush through the questionnaire, leading to inaccurate scores.

Hint: Keep the survey brief and consider the timing of its administration to maintain participant engagement.

Organizational bias: Stakeholders may have preconceived notions that affect how results are evaluated.

Hint: Present findings objectively and encourage discussions that focus on user needs over personal opinions.

Limited focus on specific tasks: SUS evaluates overall usability but may overlook specific interactions.

Hint: Combine SUS with task-based assessments to gain a fuller picture of usability.

Usability Score (SUS) is supported by various methods and tools that facilitate the evaluation of a product's usability.

Methods

Surveys: Collect user feedback through structured questionnaires to assess usability.

Usability Testing: Observe users as they interact with a product to identify usability issues.

A/B Testing: Compare two versions of a product to determine which provides a better user experience.

Heuristic Evaluation: Analyze a product based on established usability principles to identify potential problems.

User Interviews: Gather in-depth insights from users about their experiences and perceptions.

Tools

Survey Platforms: Tools like Google Forms or SurveyMonkey for creating and distributing usability questionnaires.

Usability Testing Software: Platforms such as UserTesting or Lookback that facilitate remote usability testing.

Analytics Tools: Services like Google Analytics or Hotjar for tracking user behavior and interactions.

Prototyping Tools: Applications like Figma or Adobe XD that allow for the creation of interactive prototypes to test usability.

Collaboration Tools: Platforms like Miro or Trello for organizing feedback and insights from usability evaluations.