User surveys play a significant role in assessing GUI usability by:

1. Gathering self-reported data: Surveys collect users' opinions, attitudes, and experiences with the GUI.

2. Identifying pain points: Surveys help pinpoint areas of frustration, confusion, or difficulty.

3. Understanding user needs: Surveys reveal users' goals, expectations, and motivations.

4. Evaluating user satisfaction: Surveys measure overall satisfaction, liking, and willingness to use the GUI.

5. Informing design decisions: Survey data guides design improvements, feature additions, and usability enhancements.

6. Validating usability testing findings: Surveys can confirm or contradict usability testing results, providing a more comprehensive understanding.

7. Providing quantitative data: Surveys offer numerical data, which can be analyzed statistically.

Best practices for user surveys in GUI usability assessment:

1. Keep surveys concise and focused.

2. Use clear, simple language.

3. Avoid leading questions.

4. Ensure representative sampling.

5. Analyze data statistically.

6. Combine survey data with usability testing and other metrics for a comprehensive understanding.

By incorporating user surveys into your usability assessment, you can gain a deeper understanding of your users' needs and preferences, ultimately leading to a more user-friendly GUI.