Interaction Techniques Level 2 Prepared by: RHR First Prepared on: Nov 23, 2006 Last Modified on: Quality checked by: MOH Copyright 2004 Asia Pacific Institute

Interaction Techniques

Level 2

Prepared by: RHR First Prepared on: Nov 23, 2006 Last Modified on:Quality checked by: MOH

Copyright 2004 Asia Pacific Institute of Information Technology

HCI & UsabilityCE 00306-2

Human Computer Interaction & Usability

Interaction Technique

Topic & Structure of the lesson

• Norman’s Gulfs of Execution and Evaluation• Interaction style

– Command Line– Menus– Questions and answers– Form – fills– WIMP



Learning Outcomes

• At the end of this lecture, you should be able to:– Select the appropriate interaction

technique for the interface design



Key Terms you must be able to use

If you have mastered this topic, you should be able to use the following terms correctly in your assignments and exams:

•Norman’s gulf of execution and evaluation•Interaction style

•Command line•Menus•Question and answer•Form – fills•WIMP



Models of interaction

• Norman’s Gulfs of Execution and

Evaluation – The user formulates a plan of action, which is

then executed at the computer interface. When the plan, or part of the plan, has been executed, the user observes the computer interface to evaluate the result of the executed plan, and to determine further actions



• To get something done…– Start with a goal – the goal that is to be

achieved– Take action to manipulate something– Check against your goal

Models of interaction



Models of interaction - Execution

2. Intention to act

3. Sequence of actions

1. Goals

The world

4. Execution of the action sequence



The seven stages of action1. Forming the goal

– Something to be achieved– E.g. “make a nice meal”

2. Forming the intention– Specific statements of what has to be done to achieve the

goal

– E.g. “make a chicken casserole using a can of prepared

sauce”




The seven stages of action3. Specifying an action sequence

– The precise sequence of operators that must be performed to effect the intention

– E.g. “defrost frozen chicken, open can”

4. Executing an action– Actually doing something– E.g. “opening the can”




The world

5. Perceiving the state of

the world

1. Goals

7. Evaluation of interpretation

6. Interpreting the perception

Models of interaction - Evaluation



The seven stages of action5. Perceiving the state of the world

– Perceiving what actually happened– E.g. the experience of smell, taste and look of the

prepared meal

6. Interpreting the state of the world– Trying to make sense of the perceptions available– E.g. putting those perceptions together to present the

sensory experience of a chicken casserole




The seven stages of action7. Evaluating the outcome

– Comparing what happened with what was wanted

– E.g. did the chicken casserole match up to the requirement of “a nice meal”?




• What are the 7 stages of Norman’s gulf of evaluation and execution?

Quick Review Question



Interaction Style

• Dialog between the computer and user.

• Identification of interaction styles:– Command Line Interface

– Menu

– Natural Language

– Question/ answer and query dialogue

– form -fills and spreadsheets

– WIMP



Interaction Style – Command Line

• First interactive dialog style to be used

• A mean of expressing instruction to the computer directly

using function keys, single characters, abbreviations or whole

word command

• user responds to a prompt on the screen by entering an

appropriate command




• Benefits of command line:– It offers direct access to system functionality

– Quick to use.

• The command can be applied to many objects at once

– Easily extensible

– Suitable for experience user




• Disadvantages of command line:– Difficult to use

– Difficult to learn

– Difficult for error correction

– Difficult for novice user

– Text only data representation

Hint: using consistent and meaningful commands

and abbreviations



Review question

• Can you suggest some guidelines of using the command line interface based on the above advantages and disadvantages?




Design guidelines:

• Offer maximum flexibility

– Conduct task analysis to determine the necessary

commands

• Facilitate command remembering

– Use meaningful, descriptive names

– Use consistent format of the command line

– Provide on-line help




Design guidelines:• Facilitate error correction

• Give feedback on both successful and unsuccessful commands



Interaction Style – Menus

• A set of options displayed on screen

• Relies on recognition rather than recall




• Benefits of Menus:

– Easy to use, reduces memorisation

– Structure the user’s decisions

– Easy to program




• Disadvantages of Menus:

– Limited choices per menu– Slow to use in large systems– Multi-user systems

• slow response times

– Can take up a lot of space




• Can you suggest some guidelines of using the menu and navigation interface, based on the above advantages and disadvantages?




• Design guidelines:– Group logically related options– Various categories of grouping:

• Alphabetical • Categorical • Conventional • Frequency

– Limit options to 7 per menu approximately, or break into sections

– Avoid excessively deep hierarchies– Options that are not available at a given time should be

faded (grayed).



Interaction Style – Question and answer

• Consists of computer prompt, i.e. question, set of choices, and a response from the user.

• Next question may depend on previous answer given.




• Benefits of Q&A:– Easy to use for naïve and novice users– Conversational systems– Computer initiated and controlled dialogue




• Disadvantages of Q&A:– Slow to use

– Time to read

– there is limited support for going back to correct errors that might have been made in earlier questions.

– Generally they are quite slow to use - every question must be answered in order to get through the sequence




• Can you suggest some improvements of the question and answer interface, based on the above advantages and disadvantages?




• Design guidelines:– Only one question at a time– Re-display previous answer (s) if replies are

linked– Keep sequences compatible with source

document or user task model– Display format of acceptable responses



Interaction Style: Form – Fills

• Designed for clerical workers– Requires little experience with computers– To enable them to carry out repetitive clerical

data collection tasks.– Mimicked paper forms in order to retain the

characteristics of the manual task– Designed for a specific type or task.




• Advantages– Forms offer a neat, structured way of

gathering information.

• Disadvantages– A form has to be designed specifically for

each task. – Users will require a certain level of typing skill




• Can you suggest some improvements of the form - fills interface, based on the above advantages and disadvantages?




• Design guidelines:– Text box :

• Maximum size of text-box can be determined beforehand.

– In many fields it is possible to provide a default value for a data field

– In some forms, certain values might be required, other optional.

• For required items, program might not proceed to other fields until value is entered.




• Design guidelines:– Interdependencies can be incorporated in the

program. • For example, if one element asks if user is

pregnant, then 'female' is automatically entered in the 'sex' field.



Interaction Style: WIMP

• Windows, icons, menus and pointers• The user carries out some physical action

(e.g. clicking, dragging) rather than typing commands with complex syntax

• The results of the action are seen immediately and, usually, actions are reversible




• Advantages– Novices can learn the basic functions quickly,

usually through demonstration and practice rather than from formal instruction or a manual.

– Intermittent users can retain the main operational concepts of the interface because it involves visual recognition.

– Error messages are rarely needed because most actions are reversible.




• Advantages– There is immediate feedback as to whether or

not the user's goals have been achieved.– Users are less anxious, again because they

know actions can be reversed.



Summary of Main Teaching Points

• Interaction is the heart of all modern interfaces and is important at many levels from the ordering of screens to the clicking of a button.



Q & A

Question and Answer Session

Documents

Interaction Techniques Level 2 Prepared by: RHR First Prepared on: Nov 23, 2006 Last Modified on: Quality checked by: MOH Copyright 2004 Asia Pacific Institute