exercises

12. cognitive models

EXERCISE 12.5 [extra - not in book]

This exercise is based on the mobile phone scenario on the web at: www.hcibook.com/e3/scenario/phone/

Do a GOMS abalysis of phoning a friend based on scenarios A, B and C

answer available for tutors only

This is a simple answer using the steps pretty much one by one from the scenario. You could expand parts like looking up in the address book, or typing digits. Note too the selection rules assume you know whether a person is in your address book. No provisioon for errors, unanswered calls, changed numbers, etc.

GOAL: RING-FRIEND
.     [select GOAL: USE-ADDRESS-BOOK-METHOD
.             .     FIND-NUMBER-IN-ADDRESS-BOOK
.             .     ENTER-DIGITS-FROM-BOOK
.             .     PRESS-YES-KEY
.             GOAL: USE-DIRECTORY-ENQUIRIES-METHOD
.             .     ENTER-118
.             .     GOAL: WAIT-FOR-CONNECTION
.             .           WATCH-DISPLAY until says connected
.             .     ASK-FOR-NUMBER
.             .     WRITE-DOWN-DIGITS
.             .     GOAL: HANG-UP
.             .     .     PRESS-NO-KEY
.             .     ENTER-DIGITS-FROM-PAPER
.             .     PRESS-YES-KEY
.             GOAL: USE-ELECTRONIC-PHONE-BOOK-METHOD
.             .     GOAL: GET-INTO-PHONE-BOOK-MODE
.             .     .     PRESS-LEFT-ARROW-KEY
.             .     .     PRESS-YES-KEY   --  phone book
.             .     .     PRESS-YES-KEY   --  recall
.             .     GOAL: ENTER-POSITION
.             .     .     REMEMBER-SHORTCUT
.             .     .     PRESS-DIGIT-KEY   --  if you remember!
.             .     .     PRESS-YES-KEY ]
.     GOAL: WAIT-FOR-CONNECTION
.     .     WATCH-DISPLAY until says connected
.     GOAL: TALK-TO-FRIEND
.     GOAL: HANG-UP
.     .     PRESS-NO-KEY
selection rules:
Rule 1: use USE-DIRECTORY-ENQUIRIES-METHOD unless another rule applies
Rule 2: use USE-ELECTRONIC-PHONE-BOOK-METHOD if you remember the shortcut
Rule 3: use USE-ADDRESS-BOOK-METHOD if person is in your address book

Other exercises in this chapter

ex.12.1 (ans), ex.12.2 (ans), ex.12.3 (tut), ex.12.4 (tut), ex.12.5 (tut)

all exercises for this chapter