UNIT 1: THE HUMAN

Warm up

我們將觀看一段影片 剛開始的時候，我將會詢問一個問題 請從影片中尋找答案 播放完畢時再告訴我 如果你已經看過

可以發出會心的微笑 但請不要干擾其他同學 謝謝你的合作

Inattentional Blindness

Overemphasis Easily identifiable headings & labels

你覺得左邊的網站設計如何 ?如果你一心想

買 iPhone 6…

Some Terms

較正式的定義 研究人們對訊息如何知覺、學習、記憶與思考的學科

Example issue in the scope 為什麼美國選舉候選人要花費大筆經費製作電視廣告 ?

Term Termin EnglishDescription

認知 Cognition 人如何思考

認知心理學 Cognitivepsychology

科學家思考人如何思考

學習認知心理學的學生 Studentlearning cognitive psychology

思考科學家如何思考人如何思考的人

秦朝首都

知覺有用性 ?

Computer-Mind Analogy

互動方向相反

1.1 Input-Output Channels

Five Senses

HCI HCIHCI

IBM’s 5-in-5: Taste

你為什麼喜歡吃 X?• Inductive computing• ‘food’ data• Classification• Optimization• Aim to overcome cognitive limitations

Vision

Primary source Very complex activity Two stages of visual perception

Physical reception of stimuli Processing and interpretation of stimuli

With physical limitations

Can recover from information loss

The Human Eye

Retina

Rod Cone

Location Peripheral Fovea

Light sensitivity

High Low

Light saturation

Easy Uneasy

Color vision Not good Support

Resolution Lower Higher

知覺框架

遠側物體 訊息媒介 近側刺激 知覺物體

祖母 可見光 ( 電磁波 )

視桿細胞與視椎細胞吸收光子( 波 )

祖母面孔

樹木倒地 聲波 傳導至內耳中耳蝸的接受器

樹倒的聲音

炸雞 炸雞釋放出來的分子

嗅覺上皮細胞吸收分子

炸雞

如果森林中的一棵樹倒下來，附近沒有人那麼樹倒下來時會有聲音嗎？

知覺的連續性Sensation• It’s not as

red as apples

Perception• Is it an

apple?

Cognition• Can we

eat it?

The Blind Spot

請將分發的紙張放在面前約 50cm 處 閉上左眼，用右眼盯住左邊的圓點 確認你可以看到右邊的十字 將紙張向眼睛慢慢移動，直到右邊十字消失時

停止 此時十字落入盲點 再往前一些，十字是否出現 Smart perceptual system!

Perceiving Size

Perceptual constancy Ex: the law of size constancy 姚明走遠就比我矮了…呵呵…

The ‘algorithms’ we learned Perception of depth Familiarity of target objects Other objects in the field

Which Line Is Longer?

Are These The Same Size?

Vision Illusion in Text Reading

What Do You See?

What Do You See?

What Do You See?

Reading

Three phases

Saccade + fixation Perception in fixations (94% of time)

Word recognition based on character or word? whole-word recognition Text in all caps is hard to read

Perceive visual

pattern of words

Decode with

reference to int. rep.

Conduct syntax and semantic analysis

BBC Bare eye

Shape Contrast

Vicki Walker’s email (simulated)

Which is more usable?

Reading: TV vs. Book

Published in 1982 Research problem

Is it feasible to read continuous text on CRTS for two hours or longer?

Reading speed & comprehension (book vs. TV)

32 subjects Age: 18 to 40 (Median=22) Can read English All with normal vision

Two Conditions

Book Condition (400 words/pg)

Video Condition (120 words/pg)

40rows

60 characters (at most)

39 characters (at most)

18rows

47 short stories by Nunro

Video Conditions

Video Condition (Prop.)Video Condition (Non-Prop.)

The Design & The ProcedureCondition

# of P

Set 1 (of stories)

Set 2 (of stories)

# of P

Video Condition

16

Proportional Non-proportional

8

Non-proportional

Proportional 8

Book Condition

16Read stories in Set 1 (1 hour) Read stories in Set 1 2(1 hour)

25 multiple-choice questions20 for the first 8 stories

Test (10m) Test (10m)Q

Q

Discomfort (Video vs. Book)

Reading Speed (TV Condition)

Set 2 > Set 1: F(1,14) = 7.31, p < 0.05

PropSpc = NonPropSpc: F(l, 14) < 1

Reading Speed (Video vs. Book)

Video < Book: F(1,30) = 10.3, p < 0.005

Set 2 > Set 1: F(1,30) = 16.0, p < 0.001

Comprehension (Video vs. Book)

Video = Book: F(1,30) < 1

Set 2 = Set 1: F(1,30) = 2.98

Why Books Are Read Faster?

Familiarity The difference of words per page The difference of characters per line

Reading on CRT: 80 chars/line > 40 chars/line A study by Kolers, Duchnicky, and Ferguson

(1981) The absence of control over the eye-

material distance in the Video condition 9 sec to fill the TV screen may be a

distraction

Reading Accuracy

Computer Screen in 1980Nowadays computer screen

Properties of sounds Pitch (20Hz~15kHx) Loudness Timbre

Cocktail party effect Examples of using non-speech sound

Catch attention Monitoring (without visual attention) Navigation

Processing Sounds

Sound Localization

Time difference Reduction in intensity

0.01ms

Excel Mode Error

Trying to close the window…

Excel navigation mode

• Closure • Adding a sound

Touch

The importance of haptic perception 提重物 Feeling buttons depress Braille

Sensor receptors Thermoreceptors Nociceptors Mechanoreceptors

Rapidly adapting mechanoreceptors Slowly adapting mechanoreceptors Two-point threshold test

Two-point threshold test

Aristotle’s Illusion

Kinesthesis

An aspect of haptic perception; internal

Receptors in the joints

May affect task performance (e.g., typing)

A device to feel the texture?

Movement

Reaction time + movement time Reaction time

Modality: visual (200ms)/auditory (150ms)/touch (700ms)

Skill (-) or fatigue (+) Question

Accuracy (+) or (-) reaction time?

Fitts’s Law

Movement time = a + b log2(distance/size + 1)distance: from src. to dest.size: area of target

Application of Fitts’s Law

An empirical comparison of pie vs. linear menus

Published in CHI’88

Task Type 1: Pie Tasks

OPENCLOSE UPDOWN

Typical Compass Antonyms

• North-South-East-West-NorthWest-SouthEast-NorthEast-SouthWest

• Open-Close-Up-Down-Black-White-Left-Right• Full-Empty-Dark-Light-In-Out-Active-InActive• Young-Old-Fat-Thin-Tall-Short-Top-Bottom• More-Less-Larger-Smaller-Quick-Slow-Low-High

Task Type 2: Linear TasksTask Type 3: Unclassified Tasks

1-2-3-4-5-6-7-8 One-Two-Three-Four-

Five-Six-Seven-Eight First-Second-Third-

Fourth-Fifth-Sixth-Seventh-Eighth

A-B-C-D-E-F-G-H Ape-Bear-Cat-Dragon-

Elephant-Fish-Giraffe-Horse

Linear (Lists, letters, and ordinals)

Unclassified

Hypotheses

Seek time: pie-format < linear-format Pie-task better with pie-format & linear-

task better with linear-format

Study Design

Pie task Linear task Unclassified task

Pie format 5 menus (PP) 5 menus (PL) 5 menus (PU)

Linear format 5 menus LP) 5 menus (LL) 5 menus (LU)

S1-S2-S3-S4-S5-S6• Si randomly chosen from {PP, PL, PU, LP, LL, LU}• For each Si, each subject sees 5 different menus• For each Si, each subject sees 10 menus

Participants, Material & Procedures 33 participants

Undergraduate students No or little mouse experiences

19” CRT + three-button mouse Procedures

Invocation Browsing Confirmation

Results

Menu format 存在顯著差異

task type 存在顯著差異

format

未存在顯著交互作用

Results

Analysis With Fitts’s Law

An analysis of seek time based on Fitts’s Law T = K0 + K log2(D/S + 0.5), where T = time to position cursor using mouse

(seek time) K0 = constant time to adjust grasp on mouse K = constant normalization factor

(positioning device dependent) S = size of target in pixels D = distance in screen pixels

Analysis With Fitts’s Law

13 pixels

200 pixels10 pixels

Area = 3500~6000 pixels = PA Area = ½ ~ 1/3 PA

Discussion

Please determine the main processes between the time when participants saw a task and the time when they finish the task.

Use the processes to explain: Why pie_task = linear_task <

unclassified_task (target seek time) Why linear task using pie-format menu has

the shortest time (although insignificant)? What can you improve this study with

eye-tracking?