[PDF] - Cognitiv e mo dels Ov erview goal and task hierarc hies PDF Document

SLIDE 1 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (1) Cognitiv e mo dels Ov erview

goal

and task hierarc hies

linguisti

c

ph

ysical and device

arc

hitectural

SLIDE 2 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (2) Cognitiv e mo dels They mo del asp ects

f

user:

understanding
kno

wledge

in

ten tions

pro

cessing Common categorisati

n:
Comp

etence

P

erformance Computational a v

ur

No clear divide

SLIDE 3 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (3) Goal and task hierarc hies Men tal pro cessing as divide-and-conquer Example: sales rep

rt

pro duce rep

rt

gather data . nd b

k

names . . do k eyw

rds

searc h

f

names database further sub-go als . . sift through names and abstracts b y hand further sub-go als . searc h sales database further sub-go als la y

ut

tables and histograms further sub-go als write description further sub-go als

SLIDE 4 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (4) Issues for goal hierarc hies

Gran

ularit y { Where do w e start? { Where do w e stop? { Routine learned b eha viour, not problem solving { The unit task

Conict

{ More than

ne

w a y to ac hiev e a goal

Error

SLIDE 5 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (5) T ec hniques

Goals,

Op erators, Metho ds and Selection (GOMS)

Cognitiv

e Complexit y Theory (CCT)

Hierarc

hical T ask Analysis (HT A)

SLIDE 6 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (6) GOMS Goals what the user w an ts to ac hiev e Op erators basic actions user p erforms Metho ds decomp

sition
f

a goal in to subgoals/op erators Selection means

f

c ho

sing

b et w een comp eting metho ds

SLIDE 7 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (7) GOMS example GOAL: ICONISE-WINDOW [select GOAL: USE-CLOSE-METHOD MOVE-MOUSE-TO-WI NDOW- HEADE R POP-UP-MENU CLICK-OVER-CLOSE

OPTI

ON GOAL: USE-L7-METHOD PRESS-L7-KEY] F

r

a particular user: Rule 1: Select USE-CLOSE-METHOD unless another rule applies. Rule 2: If the applicatio n is GAME, select L7-METHOD.

SLIDE 8 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (8) CCT Tw

parallel

descriptions: User pro duction rules Device generalised transition net w

rks

Pro duction rules are

f

the form: if c

ndition

then action T ransition net w

rks

co v ered under dialogue mo dels

SLIDE 9 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (9) Example: editing with vi Pro duction rules are in long-term memory Mo del con ten ts

f

w

rking

memory as attribute-v al ue mapping (GOAL perform unit task (TEXT task is insert space) (TEXT task is at 5 23) (CURSOR 8 7) Rules are pattern-matc hed to w

rking

memory , e.g., LOOK-TEXT task is at %LINE %COLUMN is true, with LINE = 5 COLUMN = 23.

SLIDE 10 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (10) F

ur

rules w

uld

mo del inserting a space: SELECT-INSER T-SP A CE INSER T-SP A CE-MO VE-FIRST INSER T-SP A CE-DOIT INSER T-SP A CE-DONE (SELECT-INSER T-SP A CE IF (AND (TEST-GO AL p erform unit task) (TEST-TEXT task is insert space) (NOT (TEST-GO AL insert space)) (NOT (TEST-NOTE executing insert space))) THEN ((ADD-GO AL insert space) (ADD-NOTE executing insert space) (LOOK-TEXT task is at %LINE %COLUMN))) When red, adds to w

rking

memory (GOAL insert space) (NOTE executing insert space) (LINE 5) (COLUMN 23)

SLIDE 11 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (11) Notes

n

CCT P arallel mo del Pro ceduralisation

f

actions No vice v ersus exp ert st yle rules Error b eha viour can b e represen ted Measures

Depth
f

goal structure

Num

b er

f

rules

Comparison

with device description

SLIDE 12 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (12) Problems with goal hierarc hies

a

p

st

ho c tec hnique

exp

ert v ersus no vice

Ho

w cognitiv e are they? Simple extensions p

ssible

(e.g., closure)

SLIDE 13 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (13) Linguistic notations Understanding the user's b eha viour and cognitiv e dicult y based

n

analysis

f

language b et w een user and system. Similar in emphasis to dialogue mo dels

Bac

kus{Naur F

rm

(BNF)

T

ask{Action Grammar (T A G)

SLIDE 14 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (14) BNF V ery common notation from computer science A purely syn tactic view

f

the dialogue T erminals lo w est lev el

f

user b eha viour CLICK-MOUSE, MOVE-MOUSE Non terminals

rdering
f

terminals; higher lev el

f

abstraction select-menu, position-mouse

SLIDE 15 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (15) Example

f

BNF Basic syn tax: nonter minal ::= expr ession An expression con tains terminals and non terminals com bined in sequence (+)

r

as alternativ es (j). dr aw l ine ::= sel ect l ine + choose points+ l ast point sel ect l ine ::= pos mouse + C LI C K M O U S E choose points ::= choose

ne

j choose

ne

+ choose points choose

ne

::= pos mouse + C LI C K M O U S E l ast point ::= pos mouse + D B L C LI C K M O U S E pos mouse ::= N U LL j M O V E M O U S E + pos mouse

SLIDE 16 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (16) Measuremen ts with BNF Num b er

f

rules (not so go

d)

Num b er

f

+ and j

p

erators Complications

same

syn tax for dieren t seman tics

no

reection

f

user's p erception

minimal

consistency c hec king

SLIDE 17 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (17) T A G Making consistency more explici t Enco ding user's w

rld

kno wledge P arameterised grammar rules Non terminals are mo died to include additional seman tic features

SLIDE 18 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (18) Consistency in T A G In BNF, three UNIX commands w

uld

b e describ ed as copy ::= cp + f il ename + f il ename j cp + f il enames + dir ector y mov e ::= mv + f il ename + f il ename j mv + f il enames + dir ector y l ink ::= ln + f il ename + f il ename j ln + f il enames + dir ector y No BNF measure could distinguish b et w een this and a less consisten t grammar in whic h l ink ::= ln + f il ename + f il ename j ln + dir ector y + f il enames

SLIDE 19 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (19) Consistency in T A G (con t'd) In T A G, this consistency

f

argumen t

rder

can b e made explicit using a parameter,

r

semantic fe atur e for le

p

erations. F eature P

ssible

v alues O p f copy ; mov e; l ink g f il e

p[O

p] ::= command[O p]+ f il ename + f il ename j command[O p]+ f il enames + dir ector y command[O p = copy ] ::= cp command[O p = mov e] ::= mv command[O p = l ink ] ::= ln

SLIDE 20 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (20) Other uses

f

T A G Users existing know le dge Congruenc e b et w een features and commands These are mo delled as derive d rules

SLIDE 21 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (21) Ph ysical and device mo dels Based

n

empirical kno wledge

f

h uman motor system User's task: acquisiti

n

then execution. These

nly

address execution Complemen tary with goal hierarc hies

The

Keystrok e Lev el Mo del (KLM)

Buxton's

3-state mo del

SLIDE 22 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (22) KLM Six execution phase

p

erators Ph ysical motor K k eystroking P p

in

ting H homing D dra wing Men tal M men tal preparation System R resp

nse

Times are empirically determined. T execute = T K + T P + T H + T D + T M + T R

SLIDE 23 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (23) Example GO AL: ICONISE-WINDO W [select GO AL: USE-CLOSE-METHOD MO VE-MOUSE-TO-WINDO W-HEADER POP-UP-MENU CLICK-O VER-CLOSE-OPTION GO AL: USE-L7-METHOD PRESS-L7-KEY] Assuming hand starts

n

mouse: USE-L7-METH OD USE-CLOSE-M ETH OD Op erator T (sec) H[to kb d] 0.40 M 1.35 K[L7 k ey] 0.28 T

tal

2.03 Op erator T (sec) P[to men u] 1.1 B[LEFT do wn] 0.1 M 1.35 P[to

ption]

1.1 B[LEFT up] 0.1 T

tal

3.75

SLIDE 24 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (24) Arc hitectural mo dels All

f

these cognitiv e mo dels mak e assumptions ab

ut

the arc hitecture

f

the h uman mind.

Long-term/Short-term

memory

Problem

spaces

In

teracting Cognitiv e Subsystems

Connectionist
A

CT

SLIDE 25 Human{Com puter In teraction, Pren tice Hall A. Dix, J. Finla y , G. Ab

wd

and R. Beale c

1993

Mo dels

f

the User in Design Chapter 6 (25) Displa y-based in teraction Most cognitiv e mo dels do not deal with user

bserv

ation and p erception. Some tec hniques ha v e b een extended to handle system

utput

(e.g., BNF with sensing terminals, Displa y-T A G), but problems p ersist. Lev el

f

gran ularit y Exploratory in teraction v ersus planning