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Human
Computer Interaction
(CS408)
VU
Lecture
10
Lecture
10. Cognitive
Processes - Part II
Learning
Goals
As the
aim of this lecture is to
introduce you the study of
Human Computer
Interaction,
so that after studying this
you will be able to:
Understand
learning
·
Discuss
planning, reasoning, decision
making
·
Understand
problem solving
·
Today is
part second of our two parts
series lecture on Cognitive
Process. As we have
earlier
seen that cognition involves
following processes:
· Attention
Memory
·
Perception
and recognition
·
Learning
·
Reading,
speaking and
listening
·
Problem
solving, planning, reasoning,
decision-making.
·
Today we
will learn about learning
and thinking. Let us first
look at learning.
Learning
10.1
Learning
can be consider in two
terms:
· Procedural
Declarative
·
Procedural
According
to procedural learning we come to
any object with questions
like how to
use
it? How to do something? For
example, how to use a
computer-based application?
Declarative
According
to declarative learning we try to
find the facts about
something. For
example,
using a computer-based application to
understand a given
topic.
Jack
Carroll and his colleagues
have written extensively
about how to design
interfaces
to help learners develop computer-based
skills. A main observation is
that
people
find it very hard to learn
by following sets of instructions in a
manual. For
example,
when people encounter a
computer for the first
time their most
common
reaction
is one of fear and
trepidation. In contrast, when we
sit behind the
steering
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wheel of
a car for the first
time most of us are highly
motivated and very excited
with
the
prospect of learning to drive. Why,
then m is there such a
discrepancy between
our
attitudes to learning these
different skills? One of the
main differences
between
the
two domains is the way
they are taught. At the
end of the first driving
lesson, a
pupil
will have usually learned
how to drive through
actually doing. This
includes
performing
a number of complex tasks
such as clutch control, gear
changing, learning
to use
the controls and knowing
what they are. Furthermore,
the instructors are
keen
to let
their pupils try thing
out and get started. Verbal
instruction initially is kept
to
minimum
and usually interjected only
when necessary. In contrast,
someone who sits
in front
of a computer system for the
first time may only
have a very large
manual,
which
may be difficult to understand
and poorly
presented.
Often training and reference
materials are written as a
series of ordered
explanations
together with step by step
exercises, which may cause
the learner to feel
overloaded
with information or frustrated at
not being able to find
information that
she
wants. One of the main
developing usable training materials
and helps facilities.
There is
general assumption that
having read something in the
manual users can
immediately
match it to what is happening at
the interface and respond
accordingly.
But as
you may have experienced,
trying to put into action
even simple
descriptions
can
sometimes be difficult.
Experienced
users also appear to be reluctant to
learn new methods and
operations
from
manuals. When new situations arise
that could be handled more
effectively by
new
procedures, experienced users are
more likely to continue to
use the procedures
they
already know rather than
try to follow the advanced
procedures outlined in a
manual,
even if the former course
takes much longer and is
less effective.
So,
people prefer to learn
through doing. GUI and
direct manipulation interface
are
good
environments for supporting
this kind of learning by
supporting exploratory
interaction
and importantly allowing
users to `undo' their
actions, i.e., return to
a
previous
state if they make a mistake
by clicking on the wrong
option.
Carroll
has also suggested that
another way of helping
learners is by using a
`training
wheels'
approach. This involves
restricting the possible
functions that can be
carried
out by a
novice to the basics and
then extending these as the
novice becomes more
experienced.
The underlying rationale is to
make initial learning more
tractable,
helping
the learner focus on simple
operations before moving on to
more complex
ones.
There
have also been numerous attempts to
harness the capabilities of
different
technologies,
such as web-based, multimedia, and
virtual reality, is that
they provide
alternative
ways of representing and
interacting with information
that are not possible
with
traditional technologies. In so doing,
they have the potential of
offering learners
the
ability to explore ideas and concepts
different ways.
People
often have problems learning
the difficult stuff---by
this we mean
mathematical
formulae, notations, laws of
physics, and other abstract concepts.
One
of the
main reasons is that they
find it difficult to relate
their concrete experiences of
the
physical world with these
higher-level abstractions. Research has
shown,
however,
that it is possible to facilitate
this kind of learning
through the use of
interactive
multimedia.
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Dynalinking
The
process of linking and
manipulating multimedia representations
at the interface is
called
dynalinking. It is helpful in learning.
An example where dynalinking
have been
found
beneficial is in helping children
and students learn ecological concepts.
During
experiment
a simple ecosystem of a pond
was built using multimedia.
The concrete
simulation
showed various organisms swimming
and moving around and
occasionally
an event
where one would eat
another. When an organism
was clicked on, it
would
say
what it was and what it
ate.
The
simulation was dynalinked
with other abstract representations of
the pond
ecosystem.
One of these was a food
web diagram. People were
encouraged to interact
with
the interlinked diagrams in
various ways and to observe
what happened in the
concrete
simulation when something
was changed n the diagram
and vice versa.
Dynalinking
is a powerful form of interaction
and can be used in a range of
domains
to
explicitly show relationships
among multiple dimensions,
especially when the
information
to be understood or learned is
complex.
Reading,
Speaking and Listening
10.2
These
three forms of language processing
have both similar and
different properties.
One
similarity is that the
meaning of sentences or phrases is
the same regardless of
the
mode in which it is conveyed.
For example, the sentence
"Computer are a
wonderful
invention" essentially has
the same meaning whether
one reads it,
speaks
it, or
hears it. However, the
ease with which people
can read, listen, or speak
differs
depending
on the person, task, and
context. For example, many
people find listening
much
easier than reading.
Specific differences between
the three modes
include:
· Written
language is permanent while
listening is transient. It is possible
to
reread
information if not understood
the first time round.
This is not possible
with
spoken information that is
being broadcast.
Reading
can be quicker than speaking
or listening, as written text
can be
·
rapidly
scanned in ways not possible
when listening to serially
presented
spoken
works.
Listening
require less cognitive
effort than reading or
speaking. Children,
·
especially,
often prefer to listen to
narratives provided in multimedia or
web-
based
learning material than to read
the equivalent text
online.
Written
language tends to be grammatical while
spoken language is
often
·
ungrammatical.
For example, people often
start and stop in mid-sentence,
letting
someone also start
speaking.
There are
marked differences between
people in their ability to
use language.
·
Some
people prefer reading to
listening, while others prefer
listening.
Likewise,
some people prefer speaking
to writing and vice
versa.
Dyslexics
have difficulties understanding
and recognizing written
words,
·
making it
hard for them to write
grammatical sentences and
spell correctly.
People
who are hard of hearing or
hart of seeing are also
restricted in the way
·
they
can process language.
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Incorporating
Language processing in
applications
Many
applications have been developed
either to capitalize on people's
reading
writing
and listening skills, or to
support or replace them
where they lack or
have
difficulty
with them. These
include:
Interactive
books and web-based material
that help people to read or
learning
·
foreign
languages.
Speech-recognition
systems that allow users to
provide instructions via
spoken
·
commands.
Speech-output
systems that use
artificially generated
speech
·
Natural-language
systems that enable users to
type in questions and give
text-
·
based
responses.
Cognitive
aids that help people
who find it difficult to
read, write, and
speak.
·
A number
of special interfaces have been
developed for people who
have
problems
with reading, writing, and
speaking.
Various
input and output devices
that allow people with
various disabilities to
·
have
access to the web and
use word processors and
other software
packages.
Design
Implications
Keep
the length of speech-based
menus and instructions to a
minimum.
·
Research
has shown that people
find it hard to follow
spoken menu with
more
than
three or four options.
Likewise, they are bad at
remembering sets of
instructions
and directions that have
more than a few
parts.
Accentuate
the intonation of artificially generated
speech voices, as they
are
·
harder to
understand than human
voices.
Provide
opportunities for making
text large on a screen,
without affecting the
·
formatting,
for people who find it
hard to read small
text.
Problem
Solving,
Planning,
Reasoning
and
10.3
Decision-making
Problem
solving, planning, reasoning
and decision-making are all
cognitive processes
involving
reflective cognition. They
include thinking about what
to do, what the
options
are, and what the
consequences might be of carrying
out a given action.
They
often
involve conscious processing (being aware of
what one is thinking
about),
discussion
with others, and the
use of various kinds of
artifacts, (e.g., maps,
books,
and
pen and paper). For
example, when planning the
best route to get somewhere,
say
a foreign
city, we may ask others use
a map, get instructions from
the web, or a
combination
of these.
Reasoning
also involves working
through different scenarios
and deciding which is
the
best option or solution to a
given problem. In the
route-planning activity we
may
be aware
of alternative routes and reason
through the advantages and disadvantages
of
each
route before deciding on the
best one. Many family
arguments have come
about
because
one member thinks he or she
knows the best route
while another thinks
otherwise.
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Comparing
different sources of information is
also common practice when
seeking
information
on the web. For example,
just as people will phone
around for a range of
quotes,
so too, will they use
different search engines to
find sites that give
the best
deal or
best information. If people
have knowledge of the pros
and cons of different
search
engines, they may also
select different ones for
different kinds of queries.
For
example,
a student may use a more
academically oriented one
when looking for
information
for writing an essay, and a
more commercially based one
when trying to
find
out what's happening in
town.
The
extent to which people engage in
the various forms of
reflective cognition
depends on
their level of experience
with a domain; applications
about what to do
using
other knowledge about
similar situations. They
tend to act by trial and
error,
exploring
and experimenting with ways
of doing things. As a result
they may start off
being
slow, making errors and
generally being inefficient.
They may also act
irrationally,
following their superstitions
and not thinking ahead to
the consequences
of their
actions. In contrast experts have
much more knowledge and
experience and
are able
to select optimal strategies for carrying
out their tasks. They
are likely to able
to think
ahead more, considering what
the consequences might be of
opting for a
particular
move or solution.
Reasoning
Reasoning
is the process by which we
use the knowledge we have to
draw
conclusions
or infer something new about
the domain of interest.
There are a number
of
different types of
reasoning:
· Deductive
reasoning
Inductive
reasoning
·
Abductive
reasoning
·
Deductive
reasoning
Deductive
reasoning derives the
logically necessary conclusion
from the given
premises.
For example,
It is
Friday then she will go to
work
It is
Friday
Therefore
she will go to work
It is
important to note that this
is the logical conclusion
from the premises; it does
not
necessarily
have to correspond to our
notion of truth. So, for
example,
If it is
raining then the ground is
dry
It is
raining
Therefore
the ground is dry.
Is a
perfectly valid deduction,
even though it conflicts
with our knowledge of what
is
true in
the world?
Inductive
reasoning
Induction
is generalizing from cases we
have seen to infer
information about cases
we
have
not seen. For example, if
every elephant we have ever
seen has a trunk, we
infer
that
all elephants have trunks.
Of course, this inference is unreliable
and cannot be
proved to
be true; it can only be
proved to be false. We can
disprove the
inference
simply by
producing an elephant without a
trunk. However, we can never
prove it true
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because,
no matter how many elephants
with trunks we have seen or
are known to
exist,
the next one we see
may be trunkless. The best
that we can do is
gather
evidence
to support our inductive
inference.
In spite
of its unreliability, induction is a
useful process, which we use
constantly in
learning
about our environment. We
can never see all
the elephants that have
ever
lived or
will ever live, but we have
certain knowledge about
elephants, which we
are
prepared
to trust for all practical
purposes, which has largely been
inferred by
induction.
Even if we saw an elephant
without a trunk, we would be
unlikely to move
from
our position that `All
elephants have trunk', since we
are better at using
positive
than
negative evidence.
Abductive
reasoning
The
third type of reasoning is
abduction. Abduction reasons
from a fact to the
action
or state
that caused it. This is
the method we use to derive
explanations for the
events
we
observe. For example,
suppose we know that Sam
always drives too fast
when she
has been
drinking. If we see Sam
driving too fast we may
infer that she has
been
drinking.
Of course, this too is unreliable since
there may be another reason
why she
is
driving fast: she may
have been called to an emergency,
for example.
In spite
of its unreliability, it is clear
that people do infer
explanations in this way
and
hold
onto them until they
have evidence to support an
alternative theory or
explanation.
This can lead to problems in
using interactive systems. If an
event
always
follows an action, the user
will infer that the
event is caused by the
action
unless
evidence to the contrary is
made available. If, in fact,
the event and the
action
are
unrelated, confusion and
even error often
result.
Problem
solving
If
reasoning is a means of inferring
new information from what is
already known,
problem
solving is the process of
finding a solution to an unfamiliar
task, using the
knowledge
we have. Human problem
solving is characterized by the
ability to adapt
the
information we have to deal
with new situations.
However, often solutions
seen to
be
original and creative. There
are a number of different
views of how people
solve
problems.
Te earliest, dating back to
the first half of the
twentieth century, is
the
Gestalt
view that problem solving
involves both reuse of
knowledge and insight.
This
has been
largely superseded but the
questions it was trying to
address remain and
its
influence
can
be seen
in later research. A second
major theory, proposed in
the 1970s by Newell
and
Simon, was the problem
space theory, which takes
the view that the
mind is a
likited
information processor. Later
variations on this drew on
the earlier thory
and
attempted
to reinterpret Gestalt theory in terms of
information-processing theories.
Let us
look at these
theories.
Gestalt
theory
Gestalt
psychologists were answering
the claim, made by behaviorists,
that problem
solving
is a matter of reproducing known
responses or trial and
error. This
explanation
was considered by the
Gestalt school to be insufficient to
account for
human
problem-solving behavior. Instead,
they claimed, problem
solving is both
productive
and reproductive. Reproductive
problem solving draws on
previous
experience
as the behaviorist claimed,
but productive problem
solving involves
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insight
and restructuring of the
problem. Indeed, reproductive
problem solving could
be
hindrance to finding a solution, since a
person may `fixate' on the
known aspects
of the
problem and so be unable to
see novel interpretations
that might lead to a
solution.
Although
Gestalt theory is attractive in terms of
its description of human
problem
solving,
it does not provide
sufficient evidence or structure to
support its theories.
It
does
not explain when
restructuring occurs or what
insight is, for
example.
Problem
space theory
Newell
and Simon proposed that
problem solving centers on
the problem space.
The
problem
space comprises problem states,
and problem solving involves
generating
these
states using legal state
transition operators. The
problem has an initial state
and
a goal
state and people use
the operator to move from
the former to the latter.
Such
problem
spaces may be huge, and so
heuristics are employed to select
appropriate
operators
to reach the goal. One such
heuristic is means-ends analysis. In
means-ends
analysis
the initial state is
compared with the goal
state and an operator chosen
to
reduce
the difference between the
two. For example, imagine
you are recognizing
your
office and you want to
move your desk from the
north wall of the room to
the
window.
Your initial state is that
the desk is at the north
wall. The goal state is
that the
desk is by
the window. The main
difference between these two
is the location of
your
desk.
You have a number of
operators, which you can
apply to moving things:
you
can
carry them or push them or
drag them, etc. however, you
know that to carry
something
it must be light and that
your desk is heavy. You
therefore have a new
sub-
goal: to
make the desk light. Your
operators for this may
involve removing
drawers,
and so
on.
An
important feature of Newell
and Simon's model is that it
operates within the
constraints
of the human processing system,
and so searching the problem
space is
limited
by capacity of short-term memory,
and the speed at which
information can be
retrieved.
Within the problem space
framework, experience allows us to
solve
problems
more easily since we can
structure the problem space
appropriately and
choose
operators efficiently.
Analogy
in problem solving
A third
element of problem solving is
the use of analogy. Here we
are interested in
how
people solve novel problems.
One suggestion is that this
is done by mapping
knowledge
relating to a similar known
domain to the new
problem-called analogical
mapping.
Similarities between the
known domain and the
new one are noted
and
operators
from the known domain are
transferred to the new
one.
This
process has been investigated
using analogous stories. Gick
and Holyoak gave
subjects
the following
problem:
A doctor
is treating a malignant tumor. In
order to destroy it he needs to
blast it with
high-intensity
rays. However, these will
also destroy the healthy
tissue, surrounding
tumor. If
he lessens the ray's
intensity the tumor will
remain. How does he destroy
the
tumor?
The
solution to this problem is to
fire low-intensity rays from
different directions
converging
on the tumor. That way,
the healthy tissue receives harmless
low-intensity
rays
while the tumor receives the
rays combined, making a high-
intensity does. The
investigators
found that only 10% of
subjects reached this solution without
help.
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However,
this rose to 80% when
they were given this
analogous story and told
that it
may
help them:
A general
is attacking a fortress. He can't
send all his men in together
as the roads are
mined to
explode if large numbers of men
cross them. He therefore
splits his men
into
small
groups and sends them in on
separate roads.
In spite
of this, it seems that
people often miss analogous
information, unless it is
semantically
close to the problem
domain.
Skill
acquisition
All of
the problem solving that we
have considered so far has
concentrated on
handling
unfamiliar problems. However,
for much of the time,
the problems that we
face are
not completely new. Instead,
we gradually acquire skill in a
particular domain
area. But
how is such skill acquired
and what difference does it
make to our problem-
solving
performance? We can gain
insight into how skilled
behavior works, and
how
skills
are acquired, by considering the
difference between novice
and expert behavior
in given
domains.
A
commonly studied domain is
chess playing. It is particularly
suitable since it lends
itself
easily to representation in terms of
problem space theory. The
initial state is the
opening
board position; the goal
state is one player
checkmating the other;
operators
to move
states are legal moves of chess. It is
therefore possible to examine
skilled
behavior
within the context of the
problem space theory of
problem solving.
In all
experiments the behavior of
chess masters was compared
with less experienced
chess
players. The first
observation was that players
did not consider large
number of
moves in
choosing their move, nor
did they look ahead
more than six moves.
Maters
onsidered
no mire alternatives than
the less experienced, but
they took less time
to
make
decision and produced better
moves.
It
appears that chess masters
remember board configurations and
good moves
associated
with them. When given
actual board positions to remember,
masters are
much
better at reconstructing the
board than the less
experienced. However,
when
given
random configurations, the
groups of players were
equally bad at
reconstructing
the
positions. It seems therefore
that expert players `chunk'
the board configuration
in
order to
hold it in short-term memory.
Expert player use larger
chunks than the
less
experienced
and can therefore remember
more detail.
Another
observed difference between
skilled and less skilled
problem solving is in
the
way
that different problems are
grouped. Novices tend to
group problems
according
to
superficial characteristics such as the
objects or features common to
both. Experts,
on the
other hand, demonstrate a deeper
understanding of the problems
and group
them
according to underlying conceptual
similarities, which may not
be at all obvious
from
the problem
descriptions.
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