CSC 8570 -- USI

1. CSC 8570 -- USI Class Meeting 3 January 23, 2009

2. Course Textbook • Carroll, HCI Models, Theories, and Frameworks is no longer readily available for reasonable cost. • Copies of relevant chapters will be provided.

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

4. Creating Tables Concerns: • 6 of 12 tables didn’t follow specifications and example row • Several examples of header row (not required by specs) poorly formatted or with less helpful labels

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

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

7. 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

8. 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

9. Where is Gregor? (5) Questions: • How do the two 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, • Push the Read button • Type a command at the prompt and press Enter • Work with a widget

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 • Quasimodes • Others?

12. Interface Examples Focus on battery operated devices on our first week’s list and other small interfaces • Remote car lock control • Watch • Cell phone • IPod • Laptop computer • PDA • Programmable thermostat • Simple calculator

13. Interface Examples (2)

14. Notation • How should we describe interactions with (or actions taken with) the interface devices? Time for some discovery groups

15. Group Work • Pair up by threes • Create a list of simple (atomic?) widgets that appear in interfaces. Consult the list of examples, generalize, then synthesize. • For each item on the list, state the actions that can be performed on it. • Suggest a notation for each action expressed in a way that it is easy to form a sequence of actions.

16. Group Work (2) Notes: • Distinguish between physical devices and actions on them and interface widgets and actions on them. Both types should be on your list.

17. Group Work Summary • Construct the union table of widgets and actions on them. • Invent the formal notation for describing the actions. • Create some examples of performing tasks using these widgets, expressing the method in the formal notation.

18. Interface Widgets • Physical devices • Keyboard • Graphical Interface Device (GID) • Point, buttons • Touch pad • Gestures, point, tap • Virtual devices • Programmed as objects and methods • Summary • Syntax vs. semantics

19. Interface Widgets (2) • The linked chart shows the summary of the group work. • The chart will be revised as • new widgets are created or discovered • new actions are needed • new notation is invented

20. Interface Models Look at: • Physical interface • Operations of physical interface • Task set • Error cost

21. 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.

22. 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

23. 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?

24. 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.

25. 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

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

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

28. 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

29. 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 Eihnihtiheihrih • bih[20] gives a string of bs • CtrliAltiDelihhh brings up the Task Manager • Drag is the same as LMB↓LMB↑[on target]

30. 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

31. 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}

32. 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)

33. GOMS (4) 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).

34. Research Project • Teams (done) • Areas (should be narrowed, can be revised) • Hypothesis • Independent variables • Dependent variables

35. Research Project (2) • Sources • ACM Digital Library • Science Citation Index • Web, but be careful • Conference proceedings, MSC 159 • Bibliography • Entered into EndNote

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

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

38. 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.

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

40. Handouts • Reprint of Chapter 3, Carroll, HCI Theories, Models, Frameworks. The chapter, written by Scott MacKenzie, deals with motor behavior models.