Folie 1

1
1st Usability Symposium HCIUE Workgroup -
Austrian Computer Society November 8, 2005
Highlighting -Or Why Google Is That
Successful Michael D. Kickmeier-Rust, Dietrich
AlbertCognitive Science Section, Department of
PsychologyUniversity of Graz, Austria
2
Human Vision

• Basics of human vision are a major foundation
  for HCI research, development, and usability
  engineering
• Visual interactions (searching / scanning /
  reading / ) are likely the most common tasks
  in HCI

1 / 99
3
Human Vision

• Crucial factors

• Legibility (e.g., font size)
• Brightness / Contrast / Saliency
• Color
• Motion

• Size
• Structure of information
• Amount / density of information

2 / 99
4
Main Questions
- Can information (text, menus, toolbars, ) be
displayed in a way that speed, accuracy, and
user satisfaction of visual search processes
is as high as possible even without knowing
what someone is searching for? - Can visual
interaction processes be optimized?
4 / 99
5
Main Questions
Origin Why was the Google design so much better
than other designs? Answer Highlighting?!?
4 / 99
6
Highlighting

• Highlighting is a well-tried and popular method
  to enhance search speed and search accuracy
• It exists a large number of previous research
  regarding the effects of highlighting and
  highlighting techniques (Philipsen, 1993,
  1994) Tullis, 1988 Van Orden, 1993)
• Often discussed in terms of highlighting
  validity (Fisher, Coury, Tangs, Duffy, 1989
  Fisher Tan, 1989)
• Highlighting validity vs. highlighting density

3 / 99
7
Mechanisms of Human Vision

• Pre-attentive stages of vision

5 / 99
8
Mechanisms of Human Vision

• Attentive stages of vision

5 / 99
9
Mechanisms of Human Vision

• Activation Map

5 / 99
10
Mechanisms of Human Vision

• Peripheral vision

5 / 99
11
Empirical Research

• The current presentation focuses on a small part
  of one of a row of experiments
• Highlighting density the percentage of
  highlighted items in the visual field

• Other variables
• Distance / distribution
• Density within a given distance
• Stimulus style (nouns, pictorial stimuli)

• Measures
• Response times
• Accuracy ( of correct responses)
• Fixation duration
• Fixation location
• Saccade length
• Saccade direction
• Comments / questions regarding satisfaction
  and convenience

2 / 99
12
Hypotheses

• Pre-attentive activation maps on the basis of
  the distribution of highlighted items
• Serial deployment of saccades along a
  reading-like scan path
• Fixations primarily on the basis of highlighted
  items
• Target detection on the basis of foveal and
  para-foveal / peripheral perception
• ? Search performance and user satisfaction
  should be highest, when an optimal density
  of highlighted items is presented

2 / 99
13
Empirical Research

• Complete experimental design (2x3x3x3)

2 / 99
14
Eye-tracking

• SMI Eyelink I eye-tracker (SensoMotoric
  Instruments GmbH Germany www.smi.de)
• Head mounted infrared camera system
• 250 Hz sampling rate
• 21 subject monitor
• Chin rest 58cm in front of the screen (not
  displayed on the photo)

2 / 99
15
Results

2 / 99
16
Results

2 / 99
17
Results

2 / 99
18

Row-wise (1)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32

Row-wise (2)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44

Column-wise (1)
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)
51
(No Transcript)
52
(No Transcript)
53
(No Transcript)
54
(No Transcript)
55
(No Transcript)
56
(No Transcript)
57
(No Transcript)
58

Column-wise (2)
59
(No Transcript)
60
(No Transcript)
61
(No Transcript)
62
(No Transcript)
63
(No Transcript)
64
(No Transcript)
65
(No Transcript)
66
(No Transcript)
67
(No Transcript)
68
(No Transcript)
69

Random
70
(No Transcript)
71
(No Transcript)
72
(No Transcript)
73
(No Transcript)
74
(No Transcript)
75
(No Transcript)
76
(No Transcript)
77
(No Transcript)
78
(No Transcript)
79
Results
2 / 99
80
Results
2 / 99
81
Conclusion
2 / 99