Transcript 了解使用者03 final

Chapter 3:
Understanding users
了解使用者
What is cognition ?
何謂認知？

當我們進行每日的例行事物時，「認知」就會在
我們的腦海中進行運作，這就是所謂的「認知程
序」。
What is cognition ?
何謂認知？
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認知有許多不同的類型，Norman(1993)
將認知區分為「體驗的認知」experimental
cognition 以及
「反思的認知」reflective cognition.
experimental cognition: 我們對週遭事物進行有
效率的接收、行動及反應的程序。E.g. drive a
car, read a book and having a conversation.
reflective cognition: 思考 比較與決策一些事物。
E.g. designing, learning and writing a book.
cognitive processes
認知的特定程序
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Attention 注意力
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Perception and recognition 知覺及辨識
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Memory 記憶
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Learning 學習
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Reading, speaking and listening 讀、說、聽
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Problem-solving, planning, reasoning and
decision-making 解決問題、進行計畫、解釋道
理、作決策
cognitive processes
認知的特定程序
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這些認知程序是會互相依存的，而且某些會和某
種特定的活動有關。
E.g.你要準備一項考試，你必須要先注意到和這
個考試的相關題材，加以閱讀、思索然後記憶，
這就是認知的一個程序。
Attention 注意力

Selecting things to concentrate on at a point in time
from the mass of stimuli around us
在一個特定的範圍或是時間點，對某些事物加以選擇性
專注的程序
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Involves auditory and/or visual senses
E.g. auditory attention : waiting in the dentist’s
waiting room for our name to be called.
E.g. visual attention: scanning the basketballs results
in a newspaper.
Attention 注意力
注意力使我們注意到與所進行的事情相關的資
訊，而這個程序進行的難易程度，有賴於：
(a) our goals 我們是否有明確的目的
(b) information presentation
我們所需要的資訊在其環境中是否清楚的
呈現
Attention 注意力
(a) our goals:我們有明確的目的時
If we know what we want to find out we try to match
this with the information that is available.
e.g. Buying printer in the Internet. Extending the
research topics from your previous tutors.
我們沒有明確的目的時
When we are not sure exactly what we are looking
for may browse through information, allowing it to
guide our attention to interesting items.
e.g. When we go to a restaurant we may have an
idea of eating, but we do not know what we want to
order.
Attention 注意力
(b) Information presentation
資訊的呈現會影響使用者注意力程序的難易度
Activity: Find the price of a double room at the
Holiday Inn in Bradley
Activity: Find the price for a double room at the
Quality Inn in Columbia
Activity
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Tullis (1987) found that the two screens
produced quite different results
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1st screen - took an average of 5.5 seconds to search
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2nd screen - took 3.2 seconds to search
Why, since both displays have the same
density of information 資訊密度(31%)?
Spacing
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In the 1st screen the information is bunched up together,
making it hard to search
In the 2nd screen the characters are grouped into vertical
categories of information making it easier
Design implications for attention
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Make information salient 突出 when it needs attending
to
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Use techniques that make things stand out like colour,
ordering, spacing, underlining, sequencing 順序排列
and animation
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Avoid cluttering 雜亂the interface - follow the
google.com example of simple design
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Avoid using too much because the software allows it
An example of over-use of graphics
Perception and recognition
知覺及辨識
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How information is acquired from the world, via the
different sense organs, e.g. eyes, ears, fingers and
transformed into experiences of objects, events,
sounds, and tastes (Roth, 1986)
資訊如何從環境中被取得，經由不同的感官(如眼、耳、手)
並轉化為物體、事件、聲音及味道相關的經驗
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人們對於知覺的效應 Vision > Hearing > Touch
Perception and recognition
知覺及辨識
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Obvious implication is to design
representations that are readily perceivable,
e.g.
 Text should be legible
 Icons should be easy to distinguish and
read
Is colour contrast good?
Bett
Are borders and white space better?
Activity
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Weller (2004) found people took less time to
locate items for information that was
grouped
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Some argue that too much white space on
web pages is detrimental 有害的 to search
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using a border (2nd screen) compared with
using color contrast (1st screen)
Makes it hard to find information
Do you agree?
Which is easiest to read and why?
What is the time?
What is the time?
What is the time?
What is the time?
What is the time?
Which is easiest to read and why?
在一般印刷品上
What is the time?
在一般標誌上
What is the time?
交通警告標誌
根據設計的複雜程度，大約五種顏色是人們能接受的數量
(Universal Principles of Design, p.38)
Design implications
Representations of information need to be designed to be perceptible and
recognizable:
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Icons and other graphical representations should enable users to
readily distinguish their meaning
Advance editing
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Sounds should be audible and distinguishable
(小綠人的登登登)
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Speech output should enable users to distinguish between the set of
spoken words (國珍老師的研究)
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Text should be legible and distinguishable from the background
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Bordering and spacing are effective visual ways of grouping
information
Book translation
Memory 記憶
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記憶提供我們許多不同種類的知識，已使我們
採取適當的行動
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We don’t remember everything –
我們會使用一種過濾的程序(filtering process)，
決定哪一些資訊要被處理與記憶，但是這個過濾的
程序並非沒有問題。(記住不該記的….)
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Context is important in affecting our memory (i.e., where,
when)
Activity Memory : words
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兩個人在游泳池中
紅色的牆面
木造的模型房子
木造餐具在杯中
Memory : Pictures
Memory 記憶
Well known fact that we recognize 辨識 things
much better than being able to recall 回憶 things
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Better at remembering images than words
Why interfaces are largely visual
Processing in memory
記憶的程序
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編碼 Encoding is first stage of memory
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編碼決定處理環境中的何種資訊，且這些資訊如何被大腦
解讀？其後，編碼動作執行的程度，會影響到我們回憶起
這個資訊的能力
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The more attention paid to something, and the more it is
processed in terms of thinking about it and comparing it with
other knowledge, the more likely it is to be remembered
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e.g., when learning about HCI, it is much better to reflect
upon it, carry out exercises, have discussions with others
about it, and write notes than just passively read a book,
listen to a lecture or watch a video about it
Context
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Context affects the extent to which information can
be subsequently retrieved
場景是如何被喚起記憶的因素
Context
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information that was encoded in a different context
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e.g., You are on a train and someone comes up to you and
says hello. You don’t recognize him for a few moments but
then realize it is one of your neighbors. You are only used
to seeing your neighbor in the hallway of your apartment
block and seeing him out of context makes him difficult to
recognize initially
大頭兵
Activity
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Try to remember the dates of your
grandparents’ birthday
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Try to remember the cover of the last two
CDs you listen
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Which was easiest? Why?
Activity Comments
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People are very good at remembering visual
cues about things
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e.g., the colour of items, the location of objects and marks
on an object
They find it more difficult to learn and
remember arbitrary material
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e.g., birthdays and phone numbers
Recognition辨識 versus recall 回憶
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Command-based interfaces require users to
recall from memory a name from a possible
set of 100s
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GUIs provide visually-based options that
users need only browse through until they
recognize one
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Web browsers, MP3 players, etc., provide
lists of visited URLs, song titles etc., that
support recognition memory
The problem with the classic ‘72’
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George Miller’s theory of how much
information people can remember
People’s immediate memory capacity is very
limited
Many designers have been led to believe
that this is useful finding for interaction
design
What some designers get up to…
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Present only 7 options on a menu
Display only 7 icons on a tool bar
Have no more than 7 bullets in a list
Place only 7 items on a pull down menu
Place only 7 tabs on the top of a website page
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But this is wrong? Why?
Why?
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Inappropriate application of the theory
People can scan lists of bullets, tabs, menu items till
they see the one they want
They don’t have to recall them from memory having
only briefly heard or seen them
Sometimes a small number of items is good design
But it depends on task and available screen estate
Personal information management
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你們是如何記住你的信用卡、金融卡的卡號？
E-mail address的密碼、PC home, Amazon的密碼？
其他的密碼？
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Personal information management (PIM) is
a growing problem for most users
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Who have vast numbers of documents, images, music
files, video clips, emails, attachments, bookmarks, etc.,
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Major problem is deciding where and how to save them
all, then remembering what they were called and where to
find them again
Naming most common means of encoding them
(what is your pet’s name?最常用的提示語)
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Trying to remember a name of a file created some time
back can be very difficult, especially when have 1000s and
1000s
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How might such a process be facilitated taking into
account people’s memory abilities?
Personal information management
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Memory involves 2 processes
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recall-directed and recognition-based scanning
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recall-directed以回億所引導:
將相關的資料記憶下來，記憶的過程越精確，使
用者越能成功的繼起所要尋找檔案的名稱
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recognition-based scanning 以辨識為基礎的掃描
當無法記起所要尋找的檔案時，便藉著瀏覽器的
檔案目錄是著喚起記憶
Personal information management
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File management systems should be
designed to optimize both kinds of
memory processes
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e.g., Search box and history list
Personal information management
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Help users encode files
in richer ways
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Provide them with ways of
saving files using colour,
image, flexible text, time
stamping, etc
Design implications
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Don’t overload users’ memories with
complicated procedures for carrying out
tasks
Design interfaces that promote recognition
rather than recall
Provide users with a variety of ways of
encoding digital information to help them
remember where they have stored them
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e.g., categories, colour, icon
Learning 學習
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學習如何使用一套軟體
使用一套電腦軟體理解一個主題
Learning 學習
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People find it very hard to learn by following
a set of instructions in a manual
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They much prefer to “learn through doing”
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GUIs are good environments for supporting
this kind of active learning
Design implications
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Design interfaces that
encourage exploration
Design implications
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Dynamically link concrete representations and
abstract concepts to facilitate the learning of
complex material
http://office.microsoft.com/training/Training.aspx?AssetID=RP061066971028
&CTT=6&Origin=RC061063991028#
Assignment
摘要與心得
作業一的研究問題
Cognitive Psychology & IA: From Theory to Practice
by Jason Withrow on 2003/08/11
http://www.boxesandarrows.com/view/cognitive_psychology_ia_from_theory_to_practice