1. HCI Meeting 23 Thurs, November 18

2. Looking Ahead Tuesday, 11/23Exam Reprise due Tuesday, 11/30 Thursday, 12/2Research Paper due Tuesday, 12/7Research Presentations Thursday, 12/9Research Presentations Friday, 12/17Final Exam @ 1:30 pm Poster

3. Research Project Remember to review style guidelines for report Use correct phrasing about results: Do not say “The hypothesis is proven.” Submit first draft of Chapters 3, 4, and 5

4. History Types Commands given Sites visited Documents opened or saved Errors made Passwords and authentication given Window/widget style Display of interface messages Display (view) of documents

5. History Models Formal description of history system Objects and methods Mathematical structures and operations Tasks: What does the user want? What does the user want to do?

6. History Tasks Independent of history type, the user may want to –Clear –View –Access –Search –Edit –Secure the history record

7. PIE Model for Browsers Command set, C: –Back (B) –Forward (F) –Home (H) –Follow link i (L i ) –Go to page j (G j ) (within the list of visited pages) Program set, P, sequence of commands Effect, E, set of displayed web pages

8. PIE Model (2) History, H = ( A, p ) where –A is the address sequence, (a 0,a 1,…,a n ) –p is the index of the active page Initially, A = (a 0 ), where a 0 is the default home page p = 0 Specify the semantics of each command by giving the change in the history pair

9. PIE Model (3) [L i ] (A, p) = [G j ] (A, p) = [B] (A, p) =

10. PIE Model (4) [F] (A, p) = [H] (A, p) =

11. PIE Model (5) Exercises: 1.Complete the semantic definitions. 2.Discover whether the semantics of some operation varies across browsers. 3.How must each of the semantic definitions be modified if the address array A is limited to at most N + 1 entries?

12. PIE Model for Document Access Command set, C –O j, open document j –S, save current document –?–? Programs, P –Is a sequence of commands meaningful?

13. PIE Model for Command Sequences Used for defining undo and redo See handout

14. Next Time Submit revised exam answers