1. Query Previews in Networked Information systems - K.Doan, C.Plaisant, B.Shneiderman Department of Computer Science University of Maryland, College park

2. Advantages of Dynamic Queries Visual representation of the Query’s components Visual representation of the results Rapid, incremental and reversible control of the query Selection by pointing, not typing Immediate & continuous feedback

3. Problems in a querying Process Network Performance Data Volume Data Complexity

4. The Two- Phase Approach Query Previews - formulation of an initial query Query Refinement Phase - furthur refinement of the datasets

5. Query Preview Phase Users formulate an initial query by selecting desired attribute values The matching datasets are shown on preview bars Undesired datasets are eliminated Focus on a manageable number of data sets

6. Initial Display of Query preview Panel

7. Query preview panel after attribute selection

8. Query Refinement Phase Input-The datasets from the Query Preview phase The datasets are furthur refined and returned in this phase

9. Query refinement Panel Search Results: Links to Faculty Pages Ben_Shneiderman: Professor, HCIBen_Shneiderman:

10. HCI Metrics Ease of Use & Navigation Good First Impression High User Retention over Time High Learnability Lesser number of user errors

11. Special Features of Query previews Can focus on a manageable number of datasets Improves Network performance Can handle large amounts of data Multiple attributes are simultaneously handled with convenience

12. Comparison with the other Methods Can handle many attributes with ease and without confusion (unlike parallel coordinates) No playing with the axes is required as in star coordinates Very easy and fast to use for first time users

13. THANKS!