Chp 40-43(Info Retrieval)

8/11/2019 Chp 40-43(Info Retrieval)

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Human Computer Interaction

Observing User


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What and when to observe

Observation is usable at all stages during productdevelopment.

Goals and questions determine the techniques used.

Observers can be:

viewers Participants

Ethnographers


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Types of Observation

Two kinds of Observation:

Controlled Environment (e.g. Lab)

Field Environment (e.g. Natural)


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How to observe

In controlled environment Decide where users are located so that equipment can

be setup

How to capture data e.g. video, interaction logs

It is important to make users feel comfortable

Problem with this approach: Observers do not knowwhat users are thinking.


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How to observe In the field

Things to be considered: The person. Who?

The place. Where?

The thing. What


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Ethnography

Its is also called participant observation:

Checklist for doing ethnography

Identify the problem or goal and ask good questions

The most important part of fieldwork is being there to

observe, ask questions and record what is seen and

heard

Collect variety of data. E.g. Notes, still pictures, audio

and video


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Data Collection Techniques


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Activity

Working on a project

Reading a books

Shopping

Using a Social media site Finding some restaurants and food places

If you are doing these tasks on your Computer then

Which are Sit down uses?

And which are Stand up uses??


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What we will learn

Users

Interviews

Questionnaires

Experts

Inspections

Walkthroughs

Asking Users and Experts


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Types of interviews

Unstructured interviews or openended

Structured interviews

Semi-structured interviews

Group interviews


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The interview process

Dress in a similar way to interviewees ifpossible, if in doubt dress neatly andavoid standing out.

Prepare a permission form and ask theinterview to sign it

Check recording equipment in advance

Be pleasant

Record answers exactly and do notmade any cosmetic adjustment , corrector change answers any way


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Things to avoid when preparing interview

questions

Long questions

Avoid compound sentences by

splitting them in two

Jargon & language that theinterviewee may not understand

Leading questions that make

assumptions e.g. why do you like ? Unconscious biases e.g. gender

stereotypes


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Probing

Devices for getting more information Start with some preplanned question and then

probes the interviewee to say more

Example

Which web sites did you visit more frequently?

Why do you like this web site?

Tell me more about web site x?

Any thing else?

You can make use of probes during interview

After Interview: Analyzing interview data which Depends on the

type of interview


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Why is it helpful to prepare an interview guide beforeconducting semi-structured interviews?

a) So That the data from different interviewees will be

comparable and relevant to your research questionsb) So that you can calculate the statistical significance of the

results

c) In order to allow participants complete control over thetopics they discuss

d) To make the sample more representative

Which of the following is not advised when planningthe question order of a structured interview?

a) Be wary of asking an earlier question that alters the of

later questionsb) Expect Some variation in the order in which questions are

asked

c) Leave questions about sensitive or embarrassing issuesuntil later in the interview

d) Group the questions into logically organized sections


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Which of the following is an example of anunstructured interview question?

a) Are you currently suicidal?

b) Would You tell me more about your childhood?c) Have you ever been physically abused?

d) Was your relationship with your father good orbad?

When the researcher wishes to gain in-depthknowledge by asking an initial question, thensubsequent questions based on theparticipant's responses, this is known as:

a) Semi-structured interviewing

b) Dialogical engagement

c) Informal interviewing

d) Unstructured Interviewing


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Questionnaire style

Questionnaires can have various stylesand can have various formats

Questionnaire format can include:

- checkboxes- ranges

- Like rating scales


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Questionnaire Make the questions clear and specific

When possible ask closed questions and offer a range ofanswers.

Think about the ordering of questions

Avoid complex multiple questions and jargon

Provide clear instructions on how to complete thequestionnaire

Advantage of electronic questionnaires Data goes into a data base

Easy to analyze Responses are usually received quickly

Copying and postage costs are lower than papersurveys

Time required for data analysis is reduced

Errors in questionnaire design can be corrected easily


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Asking Experts

Experts use their knowledge of users &technology to review software usability

Expert critiques can be formal or informalreports

Heuristic evaluation is usability inspectionmethod for computer software that helpsto identify usability problems in user-

interface design, it resembles high-leveldesign principles

Walkthroughs involve stepping through apre-planned scenario noting potential

problems


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Nielsens heuristics

Visibility of system status Match between system and real world User control and freedom Consistency and standards Help users recognize, diagnose, recover

from errors Error prevention Recognition rather than recall Flexibility and efficiency of useAesthetic and minimalist design Help and documentation


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Cognitive walkthroughs

Focus on ease of learning Designer presents an aspect of the design &

usage scenarios One of more experts walk through the

design prototype with the scenario Expert is told the assumptions about user

population, context of use, task details Involve simulating a users problem solving

process and each step in the humancomputer dialog checking to see if the usersgoals and memory for action can beassumed to the next correct action


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Pluralistic walkthroughCan be conducted by following sequence of steps

Scenarios are developed in the form of series part of the

screen

Scenarios are presented to the panel of evaluators and panel

is asked to write down sequence of actions they would take to

move from one screen to another Panelist discuss the actions they have suggested for that

ground of the review

Usually the representative user go first so that they are not

influenced by other panel members

Usability experts present their findings and finally designers

offer their comments

Panel moves on the next ground of the screen. This process

continues until all the scenarios have been evaluated


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Match the appropriate option

Closed questions Heuristic &walkthroughs

Open questions Easy to learnExpert evaluation Problem solving

process

Heuristic evaluation Richer

Cognitive walkthroughs Easiest to analyze


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Lecture 42:

Communicating users


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How we can eliminating errors?

Errors are abused

Users never want error messages

Users want to avoid consequences of making errors

Users will often not complain about error messages but it dosent mean

that they are happy getting errors.

Error message

Information displayed when an unexpected condition occurs

Often displayed using dialog boxes


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Whats wrong with error messages

Error message boxes are alerting the user to serious problems

(misconception)

What programmers think of error messages:

informing the user of the inability of the program to work flexibly

What users think of error messages:

error message boxes are seen not just as the program stopping theproceedings but, in clear violation of the axiom

People hate error messages

Humans have emotions

Programmers have wrong assumption


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Eliminating Error Messages

Can't eliminate error messages by simply discarding the code that shows

the actual error message dialog box

Must eliminate the possibility of the user making the error

Making Errors Impossible


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Improving error messages:

Requirements :

Be polite Be illuminating

Be helpful


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Alerts and confirmations

Alert (Announcing the obvious) Notifies the user of the programs action

They causes interruptions in the flow of users tasks

Easy to create

Confirmation

Gives user authority to override that action

If program is not confident, it asks for approval with dialog box

Confirmations come from program, not user


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Do we need to be told about this alert?


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The confirmation process

Confirmations pass the buck

User issues command to the computer

Program detects command of the user

Program doesnt want to take responsibility for the actions and the

command issued by the user Issues a confirmation


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Do we need to be told about these Confirmation?


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ELIMINATING CONFIRMATIONS


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Replacing dialogs: Rich visual mode-less feedback

Rich :Gives in-depth information about the status or attributes of a process or

object in the current application

Visual :

Because we can see it

Mode-less :

It requires no special action or it doesnt interrupt


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Chapter 13: Information Retrieval


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Negative audible feedback

Negative audible feedback

noise is emitted when something bad

happensAnnouncing user failure


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Positive audible feedback

Examples

Closing a door

Pressing light switch

Turning key in car ignition


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What do you prefer?

No noise vs. noise for negative feedback

No noise vs. unpleasant noise for

negative feedback No noise vs. soft and pleasant noises for

positive feedback


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Communication with Others


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Your identity on the desktop

ways of asserting identity

Programs icon

Programs name


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Program NameProgram Icon (16*16)


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Program NameProgram Icon (16 16)

Icon 32*32


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Ancillary application windows

These are windows that are not really

part of the applications functionality

Available on request


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About boxes A simple dialog box that identifies the program to user


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Splash screens

Screens that appear in first instance Used for branding and marketing


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Online Help

Online help should be provided butshould not be substitute for good design


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The WizardWizards are used to mange features of program

through series of dialogue boxes.

St d R t i l


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Storage and Retrieval

Systems Storage system

A method for safekeeping goods in a

repository

A physical system composed of acontainer and the tools necessary to put

objects in and take them back out again

R t i l t


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Retrieval system

A method for finding goods in a repository

A logical system that allows goods to belocated according to some abstract value (e.g.,

like name, position, etc.)

St d R t i l i th


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Storage and Retrieval in the

Physical World

Storage and retrieval by location

Indexed retrieval

Storage and retrieval by


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Storage and retrieval by

location In physical world, remembering where

we put an itemits address, or

locationhelps us to find it

Book

We go to where we left book, or where

others books are found We dont find books by association.


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Indexed retrieval

For large volumes, storage andretrieval by location is not possible

Libraries Dewey Decimal system Give every book an index number based

on its title and subject matter

The books are shelved in this numericalorder

If you know number, you can find book


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Retrieval methods

3 ways to find a document on acomputer

Positional retrieval (remember location)

Identity retrieval (remember name)

Associative or attributed-based retrieval

An attribute based retrieval


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An attribute-based retrieval

system Todays desktops cannot adopt an

attribute-based retrieval system

Attribute-based system could allowuser find documents by

Synonyms

Related topicsAttributes

Information architecture system


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Information architecture system

for web site Organizational systems Labeling systems

Navigational systems

Searching systems


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Chp 40-43(Info Retrieval)

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