Selasa, 09 Maret 2010

Usability Principles

After we knew the history of HCI, now we will learn about “Usability Principle”.
UI Design:
Any some categories of UI Design:
1. Learnability Principle.
Ease with which new users can begin effective interaction and achieve maximal performance.
In simply it’s easy to learn.
Learnability reveres to
a. Predictability
It’s mean the tools function have to be prediction. And user could be know what will be
happened if “I click it”. Or we can say “I think that this action will do…”.
b. Synthesizability
Support for user in assessing the effect of past operations on current system state.
c. Familiarity
That mean, everything about our design was known by user. Such us if we write “apple”
like “aple” we know that mean “apple” the fruit wit the sweet meal and the red skin.
In headline “what people used to”.
d. Generalizability
Can knowledge of one system/UI be extended to other similar ones?
 Example: cut & paste in different applications
 Does knowledge of one aspect of a UI apply to rest of the UI?
 Aid: UI Developers guidelines
e. Consistency
Likeness in behavior between similar tasks/operations/situations

2. Flexibility
Multiplicity of ways that users and system exchange information:
a. Dialog Initiative
Not hampering the user by placing constraints on how dialog is done
 User pre-emptive
User initiates actions. More flexible, generally more desirable
 System pre-emptive
System does all prompts, user responds. Sometimes necessary

b. Multithreading
Allowing user to perform more than one task at a time. Any two types e.g.
 Concurrent
Input to multiple tasks simultaneously
 Interleaved
Many tasks, but input to one at a time

c. Task migratability
Ability to move performance of task to entity (user or system) who can do it better.
 Spell-checking, safety controls in plant
 For what kinds of tasks should the user be in control?

d. Substitutivity
Flexibility in details of operations. That means:
 Allow user to choose suitable interaction methods
 Allow different ways to perform actions, specify data, configure
 Allow different ways of presenting output to suit task & user

e. Customizability
Ability of user to modify interface e.g. Windows in Bahasa (Indonesian Language).

3. Robustness
Supporting user in determining successful achievement and assessment of goals. It reverses
to:
a. Observability
User can determine internal state of system from what he understand. Such us:
 Browsability
Explore current state (without changing it)
 Reachability
Navigate through observable states
 Persistence
How long does observable state persist?

b. Recoverability
Ability to take corrective action upon recognizing error
 Difficulty of recovery procedure should relate to difficulty of original task
 Forward recovery Ability to fix when we can’t undo
 Backward recovery Undo previous error(s)

c. Responsiveness
How Users perception of rate of communication with system. Such us know about
 Response time
Time for system to respond in some way to user action(s)
 Users perceptions not always right
 Consistency important
 Response OK if matches user expectations

d. Task Conformance
That system can serve/support all tasks what user want. It’s like
 Task completeness
Can system do all tasks of interest?
 Task adequacy
Can user understand how to do tasks?
 Does it allow user to define new tasks?

Minggu, 28 Februari 2010

History of HCI

Hai... this time I try to share my knowledge to every people that read my blog. This is about “Histry of HCI”. Yeah eventough just “headline” but I hope u will get it. You will be know about Key People and Events,  Series Of Paradigma Shifts, Understanding where you’ve come from can help a lot in figuring out where you’re going, Knowledge of an area implies an appreciation of its history.
Paradigma, Predominant theoretical frameworks or scientific world views, e.g. Aristotelian, Newtonian, Einsteinian (relativistic) paradigms in physics. But Understanding HCI history is largely about understanding a series of paradigm shifts. Now, for example paradigm shift of HCI:
·        Cards,tape -> VDU
·        Mainframe -> PC (Personal Computer)
·        Glass tty -> WIMP interface
·        Commands -> Direct manipulation
·        Direct manipulation -> Agents
·        Visual -> Multimedia
·        Linear -> Web-like
·        Desktop -> Ubiquitous, Mobile
·        Single user -> CSCW
·        Purposeful use -> Situated use

About history of HCI, digital computer grounded in ideas from 1700’s & 1800’s and finaly technology became available in the 1940’s and 1950’s.
            Now the time to Key People and Events. Start from Vannevar Bush. He said that “As We May Think” - 1945 Atlantic Monthly, “…publication has been extended far beyond our present ability to make real use of the record.” . Postulated Memex device can store all records/articles/communications, Large memory, Items retrieved by indexing, keywords, cross references, can make a trail of links through material, etc. This is Envisioned as microfilm, not computer.
            J.R. Licklider in 1960 he said “Postulated “man-computer symbiosis””. Couple human brains and computing machines tightly to revolutionize information handling. And the vision / goal of Postulated is in the table.
Immed
Intermed
Long-term
•  Time sharing
•  Electronic I/O
•  Interactive, real-time system
•  Large scale information storage and retrieval

•         Combined speech recognition,  character recognition, lightpen editing

·        Natural language understanding
·        Speech recognition of arbitrary users
·        Heuristic programming


In mid 1960’s Computers too expensive for individuals e.g. Time Sharing ( increased accessibility, interactive systems, not jobs, text processing, editing, email, shared file system) need for HCI.
            Ivan Sutherland, SketchPad - ‘63 PhD thesis at MIT
-        Hierarchy - pictures & subpictures
-        Master picture with instances (ie, OOP)
-        Constraints
-        Icons
-        Copying
-        Light pen as input device
-        Recursive operations
And new paradigm of video display units:
•         More suitable medium than paper
•         Sutherland’s Sketchpad as landmark system
•         Computers used for visualizing and manipulating data.
 

           
            Douglas Engelbart (Envintor of Mouse)
Landmark system/demo:hierarchical hypertext, multimedia, mouse, high-res display, windows, shared files, electronic messaging, CSCW, teleconferencing, ...

            Alan Kay (Personal Computer, Dekstop Interface)
  • Dynabook - Notebook sized computer loaded with multimedia and can store everything

New Paradigm of Personal Computing

·        System is more powerful if it’s easier to use
·        Small, powerful machines dedicated to individual
·        Importance of networks and time-sharing
·        Kay’s Dynabook, IBM PC
·        ‘70’s IBM PC
o       Text and command-based
o       Sold lots
 

PCs with GUIs
·        Xerox PARC - mid 1970’s. Alto is local processor, bitmap display, mouse Precursor to modern GUI, windows, menus, scrollbars, LAN – Ethernet.
·        Xerox Star - ’81. First commercial PC designed for “business professionals”( desktop metaphor, pointing, WYSIWYG, high degree of consistency and simplicity). First system based on usability engineering (Paper prototyping and analysis, Usability testing and iterative refinement
·        Star, Commercial flop ($15k cost, closed architecture, lacking key functionality
(spreadsheet)).
·        Apple Lisa - ’82 (Based on ideas of Star, More personal rather
than office tool but stil $$$, and it was failure
).
·        Apple Macintosh - ’84 (Aggressive pricing - $2500, Not trailblazer & smart copier, Good interface guidelines, 3rd party applications, High quality graphics and laser printer).

New paradigm of  PCs with GUIs
·        WIMP(Windows, Icons, Menus, Pointers). Can do several things simulataneously, Familiar GUI interface, e.g. Xerox Alto, Star; early Apples

Metaphor (New paradigm)
•         All use is problem-solving or learning to some extent
•         Relating computing to real-world activity is effective learning mechanism
-        File management on office desktop
-        Financial analysis as spreadsheets

Ben Shneiderman
•         Coins and explores notion of direct manipulation of interface
•         Long-time Director of HCI Lab at Maryland
New paradigm
•         ‘82 Shneiderman describes appeal of graphically-based interaction
-        object visibility
-        incremental action and rapid feedback
-        reversibility encourages exploration
-        replace language with action
-        syntactic correctness of all actions
•         WYSIWYG, Apple Mac
•         Multimodality
§         Mode is a human communication channel
­       Not just the senses, e.g., speech and non-speech audio are two modes
§         Emphasis on simultaneous use of multiple channels for I/O
 

Ted Nelson
•         Computers can help people, not just business
•         Coined term “hypertext”
New paradigm
  • Hypertext
­       Think of information not as linear flow but as interconnected nodes
­       Bush’s MEMEX, Nelson’s hypertext
­       Non-linear browsing structure
­       WWW (World Wide Web) ’93.

Nicholas Negroponte
•         MIT machine architecture & AI group     ‘69-’80s
•         Ideas:
-        wall-sized displays, video disks, AI in interfaces (agents), speech recognition, multimedia with hypertext.
New paradigm
  • Language (Agents)
­       Actions do not always speak louder than words
­       Interface as mediator or agent
­       Language paradigm
  • CSCW (Computer-Supported Cooperative Work)
­       No longer single user/single system
­       Micro-social aspects are crucial
­       E-mail as prominent success but other groupware still not widely used
 

Mark Weiser
  • Introduced notion of “calm technology (It’s everywhere, but recedes quietly into background)
  • CTO of Xerox PARC
New paradigm
  • Ubiquity
­       Person is no longer user of virtual device but occupant of virtual, computationally-rich environment
­       Can no longer neglect macro-social aspects
­       Late ‘90s - PDAs, VEs, ...

Okay!!! I hope u know an understand about history of HCI. Actually this is my first time wrote something in blog and also in English. My new experience, so I need repairing for my English, of course from u. Thanks for read and wait for the next knowledge. I love in it. Assalamualaikum....
 Dont forget your comment please.