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									       Advanced Human-
       Computer Interaction


Revision

Advanced HCI Exam
January 2011




Dr Joan Condell
                          UNIVERSITY OF ULSTER
                    UNIVERSITY EXAMINATIONS 2010/2011
                                Semester One



              Module Code: COM719                CRN: 11880
                Title: Advanced Human Computer Interaction
                             Time Allowed: 3 hrs

Use of Dictionaries:               Dictionaries are not permitted
Examination Aids:                  Examination aids are not permitted
Instructions to Candidates:        Candidates should read this section carefully
                                   before commencement of the examination.

Answer any FOUR Questions total 3 hours therefore 3/4 hour per question
All questions carry equal marks

Students are advised to write their registration number and desk number only on any
attachment, eg graph paper, or any other documentation being submitted with their
examination script book(s).
                      Sample Question


Compare and contrast the main characteristics of the long-term
and short-term memory.

What are some of the implications of these characteristics for
interface design?
Short Term Memory –
Characteristics
   Working Memory
   Temporary storage buffer
    (20-30 secs or more with rehearsal)
   Symbolically coded information
   Limited capacity - 7 ± 2 chunks
    (Miller, 1956) (not bits/bytes)
   Number of chunks independent of
    bits/chunk
   Used for storage and decision-making
   Recency effect
    – recent input overwrites previous storage
Long Term Memory–
Characteristics

   Semantically based
   Virtually unlimited in size
   Ease of access related to:
       frequency of access / refresh
       time since last access
       number and type of associative links
       interference from other information
        activated by same associations
STM to LTM Link

   If info. is meaningful therefore
    easier to remember in short term
    and possibly long term

   Link is:
       Indirect (no conscious path)
       Asymmetric (recall faster than storage
        i.e. fast read, slow write)
          Implications for interface design

   Human processing capacity is very small
   Constant danger of overloading STM with
    unnecess. info
   Implies designers must :
       Use meaningful / familiar chunks wherever possible
       Simplify decision-making
       Minimise STM storage therefore free up STM for
        problem solving / decision-making
                        Sample Question


How the user deploys their attention has a massive effect on how
 they interact with computing systems.

Discuss how, as designers, we can structure information in the
 interface to guide and focus the user’s attention on a given task.

What are the 3 main guidelines for using ‘guiding attention’
 techniques at the interface?
         Focusing Attention at Interface
          - Relevance to HCI?

   Better understand attention to apply to design?
   How we deploy our attention has massive
    effect on how we interact with system
   How do we
       regain attention without user missing ‘window of
        opportunity’?
       focus attention for given task?
       guide attention to relevant info?
         Structure info. in interface

Easy / quick to navigate / find
  •   present not too much / too little info
  •   user won’t spend considerable time scanning


Group / order data into meaningful parts
  •   perceptual laws of grouping (Gestalt)
  •   easier to perceive structure of info.
  •   able to guide attention to appropriate info.
              Other techniques to guide
              attention in HCI

   Partition screen using windows
       e.g. discrete or overlapping sections
       to enable separation of different info types
   Spatial / temporal cues
   Colour
   Alerting techniques
       e.g. flashing / blinking /animation / reverse video / auditory
        warnings
       can become irritating – be able to turn off
           Guidelines for using ‘guiding
           attention’ techniques

   Important info needs immediate attention
       place in prominent position to catch user's eye
       e.g. Warning and alarm messages
   Less urgent info, less prominent but specific
       user will know where to look when info required
       e.g. Reports and reference material
   Info not needed very often not displayed
       made available on request
       e.g. Help facilities
                       Sample Question


Describe the 8 HCI design guidelines set out in the EC Directive
 90/270/EEC.

Give examples of how they are followed by a package
you are familiar with.
8 HCI Guidelines
1.       Consistency
     •     Internal / External / Real-world
2.       Visual clarity
3.       Compatibility with users’ expectations
     •     Compromise
4.       Flexibility and control
5.       Explicit structure
6.       Continuous and informative feedback
     •     Lexical / Syntactic / Semantic
7.       Error prevention and correction
8.       User documentation and support
     •     Printed / Online / Training
         Guideline 1: Consistency
         Important for Usability of interface - Learnability

Internal consistency: within system using metaphor/ mental
  model, interaction style and presentation
     Important for Web site design E.g. moving from page to page – menu
      bars, headings etc should be in same position
     obvious on same site

External consistency: between packages, easier to move
  from one application to another
     e.g.    Microsoft    use     same     icons     for   similar   functions
      (others may copy e.g. ‘disc’ for ‘save file’)


Real-World consistency: User interface standards (Windows,
  Macintosh, OSF/Motif), specify ‘look and feel’ (but don’t
  guarantee usability), familiar to user e.g. ‘printer’ for ‘print’
          Guideline 2: Compatibility
          with Users’ Expectations
   Simple and natural dialogue
       Avoid computer/other jargon users may not be familiar with
   User’s terminology
       Particular target e.g. In WP, command ‘Insert’ but in DTP ‘Place’
        instead for publishers familiarity
   Colour conventions
       e.g. red for warning / danger
   Task sequencing
       Find natural sequence in which users carry out tasks
       Reflected in operation of software
   Simple things simple
   ‘WYSIWYG’: What you see is what you get
           Guideline 3: Flexibility and
           Control
   Meet needs of range of users
       novice, intermediate, expert
   Sequence of commands/actions
       User should control main sequence
       E.g. in WP, type then format OR format as type
   Interleaving of tasks
       E.g. shift between 2 programs/windows without having to
        close
   Provide shortcuts/accelerator keys for experts
       E.g. Ctrl V for ‘Paste’
           Guideline 3: Flexibility and
           Control (Cont’d)
   Easy reversal of actions - undo/redo
       important for ‘control’
   Minimize modal interaction
       E.g. in spreadsheet keeping ‘Chart’ mode separate from
        ‘Data entry’ mode
   Tailorability
       Tailor toolbars to user’s liking
       E.g. Window size, colour, shortcut commands
   Provide good on-line help and documentation
       For novices
          Guideline 4: Explicit Structure
          Common sense but not always observed

   Keep interface simple and organised
   Avoid ‘featuritis’ - leads to ‘bloatware’
       Makes structure more (over ?) complex
       Common affliction for Web designers – too many animated
        graphics or visitor counters
   Design dialogues to yield closure
       Dialogues should contain just enough info to complete task
       Don’t overload STM
       E.g. on webpage where need to remember info for next
        page – such as catalogues number
              Guideline 5: Continuous
              and Informative Feedback
   Where, what, when
       E.g Cursor style
       E.g progress bar
   Completion successful?
       Direct view (seeing result of
        action directly e.g. bold)
       Message box
   Available
    commands/actions
   Minimize memory load
        N.B. cursor changes as placed over
        movable image
         Guideline 6: Error Prevention
         and Correction
   Reduce possibility of error
       Limit typing required - Use drop down lists, radio
        and checkboxes where possible
       Disable menu commands
   Provide clearly marked exits (‘Cancel’ option)
   Undo / escape
   In many programs 80% of code may be for
    error handling
           Guideline 7: User
           Documentation and Support
      Printed
          Introductory tutorial
          Command reference
          Quick review card
      On-line
          E.g. Hypertext; Help
      Training
      Help ‘desk’
N.B. Want maximum efficiency from complete HCI – this includes user support
       Guideline 8: Visual Clarity
       Can overlap with ‘Explicit structure….’ guideline



             Aim: Reduce the visual search time


                  Logical sequencing
                  Visual density and balance
                  Visual coding
                                        Covered previous

ALWAYS ASK:
Why am I including this feature
Does it help or hinder?
E.g. Visitor counter or animated graphic on website
                       Sample Question



Explain the concept of Chromatic Aberration and its significance
for the use of colour in interfaces.
        ‘Chromatic Aberration’ Phenomenon

                                     RGB



   Different colours bent by different amounts when light
    passes through lens of eye
       Difficult for eye to focus on all colours in object at same time
       Can lead to eye strain
   Avoid extreme colour pairs
       red (most bent) and blue (least bent)
       green and magenta
   Desaturate (i.e. add white) to reduce effect
       Use pastel or darker shades for large areas
                      Sample Question


Why were the 7 Principles of Universal Design created?
Describe and discuss the 7 Principles of Universal Design.
           Universal Design =
           Inclusive, hands-on approach

•   Accommodate diversity in users, applications, services
    E.g. TV, DVD player, mobile phone

•   7 Principles of Universal Design
    (www.design.ncsu.edu/cud)
•   Authors collaborate to establish principles to guide
    range of design disciplines to…
     •   Evaluate existing design
     •   Guide design process
     •   Educate designers / consumers about characteristics of more
         usable products / environments
          1      Equitable Use

    ‘The design is useful and marketable to people with
    diverse abilities’

•   Provide same means of use for all
•   Avoid segregating / stigmatising users
•   Make privacy, security and safety provisions available for all
•   Make design appealing to all
         2      Flexibility in Use

    ‘The design accommodates a wide range of individual
    preferences and abilities’

•   Provide choice of methods of use
•   Accommodate right and left handed access / use
•   Facilitate user’s accuracy / precision
•   Provide adaptability to user’s pace
          3     Simple and Intuitive Use

    ‘Use of design is easy to understand, regardless of the
    user’s expertise, knowledge, language skills or current
    concentration level’

•   Eliminate unnecessary complexity
•   Be consistent with user expectations / intuition
•   Accommodate wide range of literacy / language skills
•   Provide effective prompts / feedback during / after task
    completion
         4      Perceptible Information

    ‘The design communicates necessary information
    effectively to the user, regardless of ambient
    conditions or the user’s sensory abilities’

•   Use different modes for redundant presentation of essential info
    (pictorial / verbal / tactile)
•   Maximise ‘legibility’ of essential info
•   Make it easy to give instructions / directions
•   Make compatible with variety of techniques / devices used by
    people with sensory limitations
          5     Tolerance for Error

    ‘The design minimises hazards and the adverse
    consequences of accidental or unintended actions’

•   Arrange elements to minimise hazards / errors
•   Provide warnings of hazards / errors
•   Provides fail-safe features
•   Discourage unconscious action in tasks that require vigilance
         6      Low Physical Effort

    ‘The design can be used efficiently and comfortably
    and with a minimum of fatigue’

•   Allow user to maintain neutral body position
•   Use reasonable operating forces
•   Minimise repetitive actions
•   Minimise sustained physical effort
         7      Size and Space for Approach
                and Use
    ‘Appropriate size and space is provided for approach,
    reach, manipulation ad use, regardless of user’s body
    size, posture or mobility’

•   Provide clear line of sight to important elements for seated /
    standing user
•   Make reach to all components comfortable for seated / standing
    user
•   Accommodate variations in hand / grip size
•   Provide adequate space for use of assistive devices or personal
    assistance
                     Sample Question



Explain how the ‘user-centred’ HCI and ‘traditional’ Systems
Analysis perspectives on software development and design may
be seen as perspectives in tension.
           HCI vs.
           Systems Analysis and Design

Traditional Systems Analysis
     End user plays minor role
     User consulted on what info is input, what output is needed
      BUT don’t consider how tasks are performed
     Main emphasis on tasks ‘technical’ aspects (data structures
      and programs)


HCI Approach
     Focus on USER’S goals, needs, abilities, knowledge,
      preferences
     User involved at all stages of design
           Perspectives in Tension
           1 - Traditional Systems Analysis
   Different characteristics of design process
   Functionally oriented and data driven
   Functional requirements
        Logical flow of data
        Computational efficiency
        Ease of development

   Identify entities of significance to ‘system’
   Design notation
        E.g. Data flow diagrams, Entity-Relationship diagrams
        Often met with resistance by users (as not consulted!)
           Perspectives in Tension
           2 – HCI approach
   Identifies issues of practical effectiveness
        What suits user?
   Usability orientation/factors e.g. speed, error rates
   Quality of user interface: User requirements

   Design notation: Nothing formal - designed to
    be understood by users e.g. task hierarchy
    diagram, screen sketch
   In future integrate HCI into formal development
    rather than ‘add-on’
                      Sample Question



Describe and discuss the 4 fundamental activities of Interactive
System Design.

In particular, what are the 4 main issues with the problem
statement?
        4 Fundamental Activities of
        Interactive System Design

   Problem Statement Definition
   Information gathering (with model building)
   Building of solution (or enhancement)
   Evaluation of solution


            These activities are iterated
                ALWAYS FOCUS ON USER!
           Problem Statement:
           4 main issues
   Important to get right!
   Parts could change later as system evolves
   Statement of goal of system in phrase/sentence
       Aim: show clear understanding of what is needed
       State main assumptions

   4 issues:
       Form of solution to the problem
       Level of support to be provided - system usability
        (features needed to carry out functions, fast, flexible)
       Human activity that proposed system will support
       Users who will perform that activity
                      Sample Question


Evaluation is a very important stage in the design of a
computerised system. Hill and Hartson suggested reasons why
interface evaluation should be carried out. Outline 5 of these
reasons.
          Motivation for Evaluation
   suggest improvements to design
   confirm that SW meets all of functional/usability
    specifications
   confirm acceptability of interface and/or supporting
    materials
   compare alternative designs to determine ‘best’
   ensure that it meets expectations of customers
       don’t damage reputation
   match/exceed usability of competitor’s products/earlier
    version
   ensure that it complies with any statutory requirements
    (e.g. EU)
                     Sample Question



Differentiate between a summative and a formative evaluation.
     Formative Evaluation:
     help in ‘forming’ and reforming product during
     iterative development of prototype

   Carried out during development period
   Integral part of development process
   Purpose: to support iterative refinement
   Nature: structured, but fairly informal
   Average of 3 major ‘design-test-redesign’ cycles, with
    many minor cycles to check minor changes

                The earlier poor design
                 features or errors are
                detected, the easier and
               cheaper they are to correct
         Summative Evaluation:
         evaluate ‘summation’ of all development effort

   Done once, after implementation
   Purpose: quality control – review product to
    check it meets
       Own functional & usability specifications (is robust/reliable)
       Prescribed standards, e.g. Health and Safety, ISO
   Nature: formal, often involving statistical analysis
   Can be costly & time-consuming
   Alternative to setting up formal experimental
    environment is field/‘beta’ testing
       Release ‘beta’ and wait for real users to give feedback
                      Sample Question




List 2 advantages and 2 disadvantages of the following evaluation
methods:
Expert evaluation;
Observational evaluation;
Survey evaluation;
Experimental evaluation
           Expert Evaluation:
           Call in expert to evaluate when prototype
           reaches certain stage
       Advantages                                  Disadvantages
   Very useful for picking up                    Relies on role playing
    major design flaws                             (restricting)
   Gives overview of whole                       Dependent on experts
    interface                                      previous experience
   Few resources needed (except                  Subject to bias (expert has
    for experts)                                   different ideas to
   Cheap (providing experts fees                  developer)
    aren’t too expensive)                         Problems locating experts
                                                  Cannot capture real user
                                                   behaviour
NB: ‘Expert’ is usually someone working in Human Factors field or GUI development
         Observational Evaluation:
         Someone observes small group (3-6) of users as they
         work through specified benchmark tasks

        Advantages                  Disadvantages
   Quickly highlights            Observation can affect user
    difficulties                   activity/ performance levels.
   Verbal protocols are          Test subjects may not then be
    valuable source of info        acting like ‘normal’ users
   Can be used for rapid         Analysis of data can be
    iterative development at       time/resource consuming
    any stage                     Dependent on users being
   Qualitative data               ‘truthful’ and not holding back
                                   for fear of embarrassment
           Survey Evaluation
         Advantages                            Disadvantages
   Addresses users’ opinions and            User experience is important
    understanding of interface.              Low questionnaire response
   Can be made to be diagnostic              rates (especially by post)
   Can be applied to users and              Possible interviewer bias
    designers                                Possible response bias
   Questions can be tailored to the         Analysis can be complicated
    individual                                and lengthy
   Rating scales lead to quantitative       Interviews very time-
    results                                   consuming
   Can be used on large group of users
           Experimental Evaluation:

             Advantages                        Disadvantages
   Powerful method (depending on          High cost/resource demands
    the effects investigated)              Requires user to have knowledge
   Quantitative data for statistical       of experimental method
    analysis                               Time spent on experiments can
   Can compare different groups of         mean evaluation is difficult to
    users in same experimental              integrate into design cycle
    conditions                             Tasks can be artificial and
   Reliable and valid results              restricted
   Replicable number of times             Cannot always generalise to full
                                            system in typical working
                                            situation
                                 Sample Question


Explain what is meant by the term mental model, and outline its
importance with regard to interface design.
          The Model of the Human Processor

   Brain viewed as three interacting subsystems
    (each with memory store and processor)

       Perceptual system (storage of signals from senses
        (e.g. images, sounds; brief time memory = sensory register)
       Cognitive system (‘think’, analyse, recall from LTM;
        storage in STM/working memory)
       Motor system (called on when physical response is
        required – transmit signals to muscles)

                                    (Card, Moran and Newell, 1983)
      Model Human Processor
                                     Long
        Working Memory
                                     Term
                                     Memory

          Visual
          Sensory
          register




            Perceptual   Cognitive
            Processor    Processor
eye                                     Motor
               Action                   Processor
                                Sample Question

The human mind is better at recognising things than at
remembering them. What are the implications of this fact for
interface design?

Give examples of how this idea is applied in some common
interfaces you have used.

We say that the controls (or objects) on an interface have good
'Visibility' if there is a clear, understandable and meaningful
relationship between the action that the user performs on the
control and the result of that interaction.
                                Sample Question


Feedback is an essential element for the users to determine if the
Observed result of an action matches their goals.

Comment on the visibilty of the following common interface
controls.
-The scroll bar on a Windows application (e.g. MSWord)
-The 'Copy' function in any application.
-The rewind/back button on a DVD player.
- The steering wheel in a car.
                                  Sample Question

As an 'HCI Expert' you have been asked to carry out a
Heuristic evaluation of a software system.
You decide to concentrate on the following three usability
criteria, or heuristics.

 In each case, describe the kinds of things you would look for in
 the system to determine whether or not it passed the test.
-The behaviour of the system is consistent.
-The system provides feedback.
-The interaction dialogue is what the user would expect.
                                 Sample Question


Define and discuss the particular evaluation technique of GOMS.

Discuss the role of metaphors in designing user interfaces.

Visual Basic incorporates a number of features that are designed
to improve its usability. Describe, from your own experience with
Visual Basic, specific features that contribute to each of the
factors below. (Give at least four features in each case).
Learnability; Flexibility.
                      Sample Question



Explain the term ‘ergonomics’ and discuss its relevance in the
study of HCI.
       Specifically discuss:
       (i) the arrangement of controls
       (ii) the use of colour
       (iii) the physical environment

Explain Soft Systems Methodology and outline its importance with
regard to interface design.
RECAP




Questions 1-6

Each worth 25 marks

Answer any FOUR Questions
(total 3 hours therefore 3/4 hour per question)

								
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