halo

patrick baudisch, microsoft research, LDUX*& ruth rosenholtz, parc, ASD

april 10th, CHI 2003

*while at xerox parc, now parc inc.

+

the problem

halo <demo>

contents halo is not a focus plus context technique

(related work)

halo is a lamp shining onto the street(designing halo)

halo is 16-33% faster than arrow-based visualization techniques (user study)

build interactive halo applications! (conclusions, lessons learned)

related work driving directions

vs. route planning aids

overview-plus-detail focus-plus-context

pointing into off-screen space

halo design

cinematography1. entry and exit points

2. point of viewarrow-based techniques

3. partially out of the frame halo

rings are familiar, graceful degradation

streetlamps aura visible from distance aura is round overlapping auras aggregate fading of aura indicates distance

what we changed smooth transition sharp edge disks rings dark background light background

intrusion border

handle

space for arcs…

and for corner arcs

reserve space for content

arc length = distance

handling many objects find best (restaurant): relevance cut-off

see all (dangers): merge arcs

app designers can use

color texture arc thickness

user study

interfacesarc/arrow fading offscale 110-300m/cmmap as backdropreadability oksame selectable

size

hypothesis:halo faster

halo ring distance from display border

legend

pre-study to define tasks

8 participants (6 GPS users, 2 PDA users) informal interviews 10-40 minutes

4 tasks to be used in study

1. locate task

click at expected location of off-screen targets

had tosimulate on PC

2. closest task

click arrow/arc or off-screen location closest to car

3. traverse task

click all five targets so as to form shortest path

4. avoid task

click on hospital farthest away from traffic jams

procedure 12 participants within subject design, counterbalanced four training maps per interface/task,

then eight timed maps questionnaire

task completion time

Task Arrow interface Halo interfaceLocate 20.1 (7.3) 16.8 (6.7)Closest 9.9 (10.1) 6.6 (5.3)Traverse 20.6 (14.1) 16.8 (8.7)Avoid 9.2 (4.7) 7.7 (5.8)

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Locate Closest Traverse Avoid

Arrow interface

Halo interface

33%16%

error rateTask Arrow interface Halo interfaceLocate 23.5 pixels (21.6) 28.4 pixels (33.8)Closest 22% (42%) 21% (41%)Traverse 97.4 pixels (94.7) 81.0 pixels (96.7)Avoid 15% (35%) 14% (34%)

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Locate Closest Traverse Avoid

Arrow interface

Halo interface

participants underestimated distances by 26% participants saw ovals (gestalt laws?) we can compensate for that: width += 35%

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Locate Closest Traverse Avoid

Arrow interface

Halo interface

subjective preference

conclusions halo 16%-33% faster than arrows

– no split attention– distortion-free space– scale independent– no need to annotate distance– perceive all rings at once

[treisman & gormican] limitation: max number or rings

future work: applications where peripheral objects move and change

Thanks! try halo:

http://www.patrickbaudisch.com/projects/halo

polle zellweger, jock mackinlay,lance good, and mark stefik( “citylights” short paper talk)

scott minneman and allison woodruff

end

Extra

(a) locate (b) closest

(d) avoid(c) traverse