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Human Computer Interaction

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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.

10.1 Learning

Learning can be consider in two terms:

. Procedural

. Declarative


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?


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

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
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.



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.

10.2 Reading, Speaking and Listening

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 webbased
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.


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

. Speech-output systems that use artificially generated speech

. Natural-language systems that enable users to type in questions and give textbased

. 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.

10.3 Problem Solving, Planning, Reasoning and

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

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 ally 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 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

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,