To design a GUI that allows users to explore and manipulate data:

1. Define user goals and tasks: Understand what users want to achieve with the data.

2. Provide data filtering and sorting: Enable users to narrow down and organize data.

3. Offer interactive visualizations: Incorporate charts, tables, and maps that respond to user input.

4. Implement drill-down capabilities: Allow users to access detailed data from summaries.

5. Include data manipulation tools: Provide features for editing, aggregating, and transforming data.

6. Design intuitive navigation: Organize data and tools in a logical, easy-to-follow manner.

7. Use clear and concise labeling: Ensure users understand data and tool functionality.

8. Provide feedback and guidance: Offer tooltips, hints, and tutorials to assist users.

9. Ensure responsiveness: Make the GUI adaptable to various devices and screen sizes.

10. Test and refine: Validate design decisions through user testing and iterate accordingly.

Additionally, consider:

- Using drag-and-drop interfaces for data manipulation

- Incorporating search and find functionality

- Providing data export and import options

- Offering user customization and personalization

- Ensuring data integrity and security

- Using animation and transitions to enhance user experience

By following these guidelines, you can create a GUI that empowers users to explore, manipulate, and gain insights from data effectively.