CSC 8570 -- USI

1. CSC 8570 -- USI Class Meeting 3 September 7, 2010

2. Homework for Today • Research team membership • Finished • Research areas • Comments sent

3. Creating Tables Concerns: • 3 of 7 tables didn’t follow specifications and example row

4. Where is Gregor? One of the initial questions • Process vs. system • Systems: • Google Maps (maybe Satellite View) • Google Earth • Personal GPS (maybe phone-based) • Printed map

5. Where is Gregor? (2) • Process: • Use GPS, read off coordinates • Read from map • Read from mapping software

6. Where is Gregor? (3) Example: Google Earth • Start Google Earth • Enter “Villanova University” in search dialog box • Drag map to center on statue • Zoom to highest resolution • Point to statue • Read coordinates: 4002’15.92”N 7520’29.53”W

7. Where is Gregor? (4) Example: Garmin GPS • Push “on” button, label with light icon • Wait for satellite acquisition • Push “Page” button • Place GPS at Gregor’s feet and read location 40 02.290’ N 75 20.505’ W

8. Where is Gregor? (5) Example: Google Maps • Start Google Maps • Enter “Villanova University” in search dialog box • Switch to satellite view • Drag map to center on statue • Zoom to highest resolution • Point to statue (oops, no coordinates show) • Now what?

9. Where is Gregor? (6) Questions: • How do the answers compare? • How big is one hundredth of a second? • How big is one thousandth of a minute?

10. Generalizing How do users interact with the interface? Historically, starting a long time ago • Push the Read button • Type a command at the prompt and press Enter • Click on a widget • Touch a widget • Multitouch the screen

11. Interacting with the Interface Issues are: • Types of interface widgets • Methods of interaction • Formal notation for interactions • Extensions to the Keystroke Level Model • Timings for each simple interaction • Interactions for control vs. for content • Modes and quasimodes • Others?

12. Interface Models Look at: • Physical interface • Operations of physical interface • Models of the physical interactions • Task set (of possible interactions) • Error cost

13. Error Cost • Definition: The cost, measured in time or keystroke level actions, needed to recover from an erroneous action with a widget. • Example: Mistyping “the” as “teh”. Error cost is four keystrokes: 2 backspace and 2 for the correct keys.

14. Models of Physical Action • Fitts’ Law: moving a cursor to a target • Keystroke Level (Card & Moran): timing predictions for a task represented as a sequence of “physical” operations • Hick’s Law: time for choosing among a number of widgets

15. Models of Interaction All presume that a task is completed with a sequence of (atomic) actions. • KLM (seen before) • GOMS and extensions: deals with choices of paths to completion • PIE: deals with visible and invisible states

16. Models of Interaction (2) • BNF: formal specification of an interaction grammar • FSM: Finite State Machine or • Finite automaton • STN: State Transition Network

17. Actions on Keys From your slip of paper

18. Descriptions of Actions • Report on phrase grammar • Number of phrases generated? • 96 or 88 (w/o push) or 84 • Number of meaningful phrases? • 52, 34, 59, 65, 75, 69, 24 • Mapping of phrases to actions?

19. Notations for Actions Actions for a keyboard and graphical input device (GID) include: • Tap: pressing and immediately releasing a key. Implemented with a momentary contact (spring-loaded) switch. • Click: Position the GID and tap the GID button. • Double click: Position the GID and tap the GID button twice quickly, without repositioning.

20. Notation for Actions (2) • Keystroke Level Model • K[ ], a keystroke. E.g. K[b] means tapping lower case b • P, pointing. E.g. positioning the GID • H, homing. E.g. moving from keyboard to GID or GID to keyboard • M, mental processing • R, responding

21. Notations for Action (3) • What does the description To create a right justified paragraph, use Control + . ask you to do?

22. Notations for Action (4) More actions: • Press and hold a key • Release a key • But on what signal or input?

23. Notations and Actions (5) • Raskin/Beck • Press and hold: bi • Release: bh • Tap: bibh, shortened to bih or just b • Release on signal: bh[ ] • Note that key names are italicized • Examples: • Create an upper case M: ShiftimimhShifth, shortened to Shiftimihh

24. Notations for Action (6) • Examples (continued) • Distinguish between Enter and E n t e r Enter is the name of a key and E n t e r is short for Shiftieihhnihtiheihrih • bih[20] gives a string of bs • CtrliAltiDelihhhbrings up the Task Manager • Drag is the same as LMBiLMBh[on target]

25. Fitts’ Law The time to move a cursor to an object is given by T = A log (D/S) + B where A, B are constants, D is distance, S is size Think about interpretations and limiting cases.

26. Fitts’ Law Questions • How does Fitts’ Law generalize to 2-dimensional targets? • Where does the user aim? • Where does the user land? • What path is followed? • What happens with partially hidden targets?

27. GOMS Model for user interaction • Goal: task to be accomplished • Operators: set of atomic actions provided by system • Methods: set of sequences of operators. Each sequence accomplishes the goal • Selection rule: Governs which method the user chooses to use

28. GOMS (2) Example: • Goal: Unlocking the rear doors on a car using a three-button remote control. • Operators: {Lock, Unlock, Panic} • Methods: {Double click Unlock} • Selection Rule: {Only method available}

29. GOMS (3) Example: • Goal: Selecting an item from a menu • Method: • Find menu heading • Point cursor at menu heading • Click “mouse” button (displaying menu entries) • Find desired entry • Point cursor atmenu entry • Click “mouse” button (choosing menu option)

30. GOMS (4) Exercise: (for the interested student) Assume that you manage your email messages using a hierarchy of folders that is at least five levels deep. Develop a GOMS analysis for deleting a message in a level three folder when you currently are reading messages in your inbox (a level one folder).

31. Research Project • Teams (done) • Areas (should be narrowed, can be revised) • Hypothesis • Independent variables • Dependent variables • Theoretical foundation • Which models from this evening’s discussion apply?

32. Research Project (2) • Sources • ACM Digital Library • Look carefully at entries; follow up on citations • Science Citation Index • Web, but be careful • Have you edited a Wikipedia entry? • Have you checked www.dhmo.org? • Conference proceedings, MSC 159 • Bibliography • Entered into EndNote

33. Research Project (3) • IRB Form • Consent form • Data gathering process

34. Research Project (4) • Experimental design • Between subjects • Within subjects • Sources of bias • Sources of subjects • Logic of conclusions

35. Next Time • Carry out research project activities • Create a GOMS model for constructing the table of sums of powers of 2. The methods must be at the keystroke level and include the 45 keystrokes necessary to enter the data.

36. Next Time (2) • Research project • Submit hypothesis, independent variables, dependent variables • Submit draft of IRB form • Submit bibliography as printed from EndNote