Zhenqing WUHongbo MENG

Xiaoda LUYongkang GUO

Yao DING

To develop a statistically reliable analysis on possible factors that may have influence on the usability of Chinese input on mobile phones.

Usability◦ Average typing speed◦ Error rate◦ User satisfaction

Usability

Input device

UserMeasurement Environment

Text

Input method

Keypad

Difficulty

Background noise

Temperature

Length

Age

Punctuation

Mandarin level

Concentration Lightness

Key size

Surveyor

Key shape Screen size

Layout Hand-writing

Stroke

Pinyin Touch-screen

Button

Input methods◦ Pinyin◦ Stroke

Input devices◦ Touch-screen◦ Button

Keypad layout◦ Numeric keypad◦ Full keypad

Associating input Fonts Screen contrast Screen brightness Environment factors

Differences among subjects◦ Mandarin level◦ Chinese input habit◦ Concentration

Differences among testing materials–- Testing material design guidelines◦ 不是成句的词组形式，否则输入法处理过于简易；◦ 句式不可过于复杂，避免因此而导致的测试者之间的噪音；◦ 句子长度控制在 20字左右为佳；◦ 句子之间的标点应该保持一致，避免因为标点转换而造成的时间差异。

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Combination Input method Keypad layout Input device

A Pinyin Numeric keypad Touch-screenB Pinyin Numeric keypad ButtonC Pinyin Full keyboard Touch-screenD Pinyin Full keyboard ButtonE Stroke Numeric keypad Touch-screenF Stroke Numeric keypad Button

6*6 Latin square design

Testing material

Subject

1 2 3 4 5 6

1 A F E D C B

2 B A F E D C

3 C B A F E D

4 D C B A F E

5 E D C B A F

6 F E D C B A

Average typing speed◦ Stop watch

Error rate◦ Number of clicking “backspace”

To eliminate the two nuisance sources of variability:◦ The test material used◦ The different subject chosen for the test

• Since there are six treatments, six subjects are chosen and they are tested on six different test materials.

Model:yi=µ+αi+βj+τk+ξijk

Data for input time and input speed are collected as follows:

Input time:◦ Significantly different among treatments◦ Insignificant difference among subjects and

materials

Input accuracy◦ Significantly different among subjects ◦ Insignificant difference among treatments and

materials

At first a 23 full factorial design Swapped to separately process pinyin input

data and stroke input data◦ No possible combination of full keyboard and

stroke◦ People stick with one preference among pinyin

input method and stroke input method

22 full factorial design

Deal with different combinations of subjects and materials as replicates of each design (No significant effect is shown in the Latin square analysis)

3210- 1- 2- 3

99

95

90

80

70

605040

30

20

10

5

1

标准化效应

百分

比

A Key LayoutB Key Type

因子 名称

不显著显著

效应类型

B

A

标准化效应的正态图 Speed Al pha = . 05)（响应为 ，

3210- 1- 2- 3

99

95

90

80

70

605040

30

20

10

5

1

标准化效应

百分

比

A Key LayoutB Key Type

因子 名称

不显著显著

效应类型

B

A

标准化效应的正态图 Speed Al pha = . 05)（响应为 ，

Effect of factors◦ Numeric keyboard would increase speed◦ Button keys would increase speed

Best Combination:◦ Numeric keyboard + Button keys

Worst Combination:◦ Full keyboard + Touch screen

Two-sample t-test◦ P-Value=0.672>α◦ No significant difference

Consideration of user habits Sample size

500- 50- 100

99

95

90

80

70605040

30

20

10

5

1

效应

百分

比

A AB BC C

因子 名称

不显著显著

效应类型

A

效应的正态图（响应为 C10，Al pha = . 20)

Lenth 的 PSE = 30. 375

Subject 1

Pinyin is very helpful

Most users

Need more factors to do future experiment

100500- 50- 100

99

95

90

80

70605040

30

20

10

5

1

效应

百分

比

A AB BC C

因子 名称

不显著显著

效应类型

效应的正态图（响应为 C8，Al pha = . 05)

Lenth 的 PSE = 43. 75

Most users

Need more factors to do future experiment

10- 1- 2- 3

99

95

90

80

70605040

30

20

10

5

1

效应

百分

比

A AB BC C

因子 名称

不显著显著

效应类型

AC

效应的正态图（响应为 C11，Al pha = . 05)

Lenth 的 PSE = 0. 375

Subject 1

input method and key type(touch or button)

0. 50. 0- 0. 5- 1. 0- 1. 5

99

95

90

80

70605040

30

20

10

5

1

效应

百分

比

A AB BC C

因子 名称

不显著显著

效应类型

B

A

效应的正态图（响应为 C12，Al pha = . 05)

Lenth 的 PSE = 0. 125

Most users

whether the input method is Pinyin or Stroke and whether the key layout is full or numberic keyboard are very critical.

For the input speed, each people may have different significant factors, for the most users, it seems like that we have to include other factors to give further conclusion.

For the input accuracy, people may have different significant factors just like their impact on input speed, however, for the most users, we can conclude, that Pinyin and Numeric keypad are very helpfull to reduce the error rate.

Content◦ Basic information of subjects◦ Indices rating from 1 to 7

Shortcomings◦ Limited number of subjects◦ Varied rating tendency◦ Underlying interactions

Pinyin is preferred while stroke possess a high variationPinyin is preferred while stroke possess a high variation

Button and touch-screen posses similar rating, and all vary significantly

Button and touch-screen posses similar rating, and all vary significantly

Full keyboard

Underlying interactions existUnderlying interactions exist

Thanks!