CSC 8570 -- USI

1. CSC 8570 -- USI Class Meeting 3 September 12, 2007

2. Homework for Today • Research team membership • Finished • Research areas • Comments sent • GOMS analysis • Hand in

3. Creating Tables Concerns: • 7 of 14 tables didn’t follow specifications and example row • Several examples of header row (not required by specs) poorly formatted or with less helpful labels

4. 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?

5. 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

6. Interface Examples (2)

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

8. Group Work • Pair up by threes, except one pair of two. • 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.

9. 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.

10. 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.

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

12. 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

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

14. 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.

15. 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

16. 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?

17. 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.

18. 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

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

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

21. 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

22. 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

23. GOMS • 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)

24. GOMS (2) • 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).

25. GOMS (3) • Goal: • Operators: • Methods: • Selection rule:

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

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

28. Research Project (3) • IRB Form • Consent form

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

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

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

32. The Future of HCI John Canny, The Future of HCI, from HCI, 4(2006), July/August • Do Canny’s views match our ideas? • What did he miss? • What did we miss?

33. Research Team Meetings