Introduction
Why is it important to
consider product usability in a project? Which informatics professions make use
of usability engineering ?
What are typical errors
in completed design that did not také into accont the principles of usability ?
Comment, give an example from practise.
An interface design is
based on the following principles:
Explain these issues and
scetch related techniques and theoretical foundations.
Task and user centered design
Task centered system
design concerns with end-user perspective. Explain the phases: identification,
requirements, design, walkthrough evaluation. State the goals of each phase and
what techniques are suitable to achieve them.
How would you identify
real users of a system and their tasks ? Discuss approaches where users and
tasks already exist and where not (will arise in future) Jak identifikujete
skutečné uživatele systému a jejich
úlohy ? Zvažte přístupy, kdy uživatelé a
úlohy již existují a kdy ještě neexistují
(vynoří se v budoucnosti).
What properties must have
good task examples ? What facts are recorded and what is described ?
Characterize evaluation
of design using walk-throughs. What is input for a walk-through, what
properties are tested and evaluated ? Describe the process of evaluation.
Explain and argument the
main differences between goal oriented design and task oriented design.
A goal centered design
emphasizes the development of persona and defining of characters - roles of
system users. What characteristics describe persona, how do we identify
them ?
High level models of human-computer interaction
Schneiderman's model of
interaction distinguishes semantic and syntactic knowledge. Which usability
problems are related to syntactic knowledge ?
Schneiderman model of
interaction distingueshes semantic and syntactic knowledge. Which usability
problems are related to semantic knowledge of computer concepts and task
concepts ? Characterize mapping problems.
In a simplified Norman
model we consider 4 stages of interaction (intention, selection, execution,
evaluation). Explain these stages and their interrelations when performing a
task.
4-stages model identifies
gulfs of execution and evaluation. Explain these issues.
4-stages model supports
design solution by raising and considering questions on
visibility, quality of conceptual
model, good mappings a high-quality feedback.
Explain, comment, give
examples.
User centered design
Explain the difference
between system-centered and user-centered design.
What is participatory
design, positives and negatives.
Methods for involving the
user - customer. Explaining design, visualization, scetching and prototyping.
Explain these techniques and their usage in early and late design stages.
Explain the following
attributes of scetches in the design process: quick, timely, disposable,
plentiful, clear vocabulary, constrained resolution, consistency with state,
suggesting and exploring.
When designing we use
prototypes with a constrained functionality (horizontal, vertical, scenarios).
Explain differences and usage.
Evaluating interfaces with users
Evaluating interfaces
with users is applied in all stages of project lifecycle. What are its main
goals in the following stages: pre-design, initial design, iterative
deasign, acceptance testing ?
What are the differences
between naturalistic and experimental approaches to evaluation ? Explain the
tradeoffs and external and internal validity of testing.
Evaluate pros and
problems of experimental asessment of the usability of real product. How can be
the problems partially eliminated ?
Usability evaluation
applies low cost methods, such as inspection, extractin the conceptual model,
observation, query techniques and continuous evaluation. Characterize these
techniques and discuss pros and cons.
Designing questionnaries
it is neccesary to determine the goals, formulate questions, define set of
responders and the way of carrying out.
Questions may be opened or closed. Explain the issues, give
examples.
Explain the basic ethic
principles before testing: user's time, comfort, privacy, informing,
volunteering.
Explain the basic ethic
principles during testing: user's time, comfort, privacy.
Explain the basic ethic
principles after testing: comfort, privacy, informing.
Controlled
experiment focuses on: hypothesis,
measurement, confidence, replicability, control of variables and conditions,
unbiased execution. Comment and explain the issues.
T-test
and null hypothesis. Significance level and errors of type 1 and 2.
Consequences for design decisions.
Four
scales of measurement are nominal, ordinal, interval, ratio. Explain briefly,
give examples and consider the possible sources of errors.
Explain
correlation, regression and ANOVA.
The
following concepts are important for designing:
perceived
affordances, causality, visible constraints, mapping, transfer effects,
idioms&population stereotypes, conceptual models, individual differences,
difficulty of design. Explain the selected concepts, provide positive and
negative examples.
Why is design hard ?
Consider latest developments, influence of market, prices and specific problems
related to the fact that "product" is implemented in a
general-purpose computer.
Tufte formulated the
following principles for data visualization: show the data, do not hide the
message, avoid distortion, many in small space, large set make coherent,
encourage comparison, overview and detail together, clear purpose. Comment
these principles in a selected application (several screen snapshot).
Visual variable
attributes are: position, size, shape, value, orientation, clour, texture, motion.
The attributes may be selective, associative, quantitative, order,
length. Comment these characteristics for the selected attributes.
The snapshots of a given
application contain visual variables with specific attributes. Mark these
attibutes and asses the characteristics they express.
What are interface
metaphors, theirs purpose and possible problems ? Comment emotional coloring,
possible restrictions, typical errors of metaphors' usage (overly literal,
cute, mismatched).
Explain "interface
with direct manipulation" and related issues visibility, reversible and
incremental actions, pointing and moving, continuous display. Provide
an example of direct manipulation interface and comment where, and in what form
are these notions used.
Screen design can guided
by CRAP (contrast, repetition, alignment, proximity). What these principles
enforce and guarantee ? Show their application on a given screen snapshot.
CRAP (contrast,
repetition, alignment, proximity) may be supported by grids. Compare given
screen snapshots and criticize the design using CRAP&grid principles.
What
are KLM( KeystrokeLevelModel) and GOMS (Goal, Operator, Method, Selection rule)
models used for ? Compare efforts and explain their usage in practise.
Describe
a general model of human processing of external information. Explain the
cooperation of perceptual, cognitive
and motor systems during interaction. Discuss how the parameters memory capacity, decay, representation and
processing cycle time influence interaction. Explain the model on a
given example.
Reaction
time is closely related to decision-making. What are the factors influencing
decision time ? Explain Hick-Hyman law of reaction time.
Usage
of Fitt's law in KLM evaluation.
Characterize
manipulation techniques according metaphores:
Exocentric
m. – WIM, automatic scaling
Egocentric
m. – Virtual hand (clasical, GoGo,…)
– Virtual pointer (ray
casting, aperture, flash light, image plane)
What
are advantages and disadvantages of selected methods whe used for closed and
distant manipulation ?
Metaphores
and techniques for way-finding in virtual environment.
For
evaluating interfaces various criteria may be used, such as following
heuristics:
Evaluate
a selected application given several sreen snapshots.