User Support

Material from

Authors of Human Computer Interaction

Alan Dix, et al

Overview

Users require different types of support at different times.

Basic requirements available but unobtrusive accurate and robust consistent and flexible

Design of user support must take account of: presentation issues implementation issues

Types of Support

Quick reference Task specific help Full explanation Tutorial

Types of support

Quick reference reminder of details; assumes familiarity eg command syntax, options, etc.

Usage: telnet [-8] [-#] [L] [-a] [-d] [-e char]

[-l user] [-n tracefile] [-r] [host-name [port]]

Task specific help addresses problems with

particular tasks focused on what is currently

being done

Types of Support

Full explanation for more experienced and inquisitive users likely to include information not needed now Unix man command

Tutorial aimed at new users

Types of support

Four types are complementary Together they support range of points in user’s

experience with system

Each type may be on-line and off-line (documentation) should be consistent in content presentation medium may have impact on design general principles for both

Requirements

Availability Accuracy and Completeness Consistency Robustness Flexibility Unobtrusiveness

Requirements

Availability accessible any time during application interaction

Accuracy and completeness consider incremental update/feature-adding of

releases

Consistency different parts of help system and documentation

consistent in content, terminology and presentation

Requirements

Robustness system itself should be robust even more important with support, because users

are in trouble when using it Flexibility

meets needs of user allows user to get information in an appropriate form

context sensitive or adaptive help systems Unobtrusiveness

shouldn’t block work in application

Approaches to User Support

Command Assistance Command Prompts Context-Sensitive help On-line tutorials On-line documentation Wizards Assistants

Approaches to user support

Command assistance good for reference on command, eg man or help user must know what to look for

Command prompts provide information when error occurs good for syntactic errors won’t tell you if you need a different command

Context sensitive help depends on what user is doing eg. completing a dialog, tool tip

Approaches to User Support

On-line tutorials introduces user to components of system structure progress, maybe at user’s own speed includes examples, test environment to

simulate interface useful, but inflexible

On-line documentation printed material in electronic form eg readme files continually available but can be difficult to

browse Hypertext can support browsing

Approaches to User Support

Wizards task specific tool that leads user through task step-

by-step user answers ‘questions’ along the way constraining - may not offer options should have progress indicator and allow back up

Approaches to User Support

Assistants monitor user behavior and

offer suggestions unobtrusive and under user

control ‘Clippy’ not unobtrusive,

suggestions inappropriate

MS XP smart tags appear near object of interest

Intelligent Help: Adaptive Help Systems Use knowledge of the user, task, domain and

instruction to provide help adapted to user’s needs.

Problems: Knowledge requirements considerable

must collect data on by monitoring interaction Issue of control - how active? What should be adapted? What is scope of adaptation? :

Knowledge representation: User modeling User modeling

single, generic user (non-intelligent) user-configured model (adaptable) system-configured model (adaptive)

Static help systems can’t address all user differences.

Adaptive help systems model users, refining the model by monitoring a user’s activities, and present help tailored to the particular user.

Approaches to User modeling

Quantification user moves between levels of expertise based

on quantitative measure of what he knows

Move from level 1 to level 2 if

system has been used more than twice

commands x and y used effectively

help has not been accessed in this session

system has been used in last 5 days

Approaches to User modeling

Stereotypes user is classified into a particular category

Overlay an idealized model of expert use is constructed actual use compared to it can determine how far user is from optimal use can suggest optimal use strategies

Knowledge representation: Domain and Task Modeling Usually involves analysis of command

sequences Assistants and agents

Covers common errors and tasks command sequences for current task

Problems interleaved tasks user intention

Techniques for Knowledge representation

Rule-based Frame-based Network-based Example-based

Techniques for Knowledge Representation Rule-based

knowledge represented as rules facts interpreted using inference (logic) used in large domains

IF command is EDIT file 1 AND last command is COMPILE file 1THEN task is DEBUG action is describe automatic debugger

Techniques for Knowledge Representation Frame-based

knowledge stored in structure that contains labeled slots

slot has default value useful in small domains

UserExpertise level: noviceCommand: EDIT file 1Last command: COMPILE file 1Errors this session: 6Action: describe automatic debugger

Techniques for Knowledge Representation Network-based

knowledge represented as relationships between facts

can link frame-based representations

CC is and instance of COMPILECOMPILE is a commandCOMPILE is related to DEBUGCOMPILE is related to EDITAutomatic debugger facilitates DEBUG

Techniques for Knowledge Representation Example-based

knowledge represented within decision structure of classification system

trained to classify rather than programmed with rules (AI techniques

detects recurrent features

EDIT file 1COMPILE file 1

trains for task debug

Problems with knowledge representation and modeling Knowledge difficult to elicit

especially if domain expert not available variability of users difficult to ensure completeness and

correctness

Interpretation of information during interaction all we have are logs do not have user’s intent or goal

Other issues

Initiative Does user retain control or can system direct

the interaction? Can system interrupt user to offer help?

Effect Model only what is needed to satisfy

requirements of help system Scope

Is modeling at application level only or at system level?

Designing User Support

User support is not an ‘add on’ - it should be designed integrally with system.

Should concentrate on content and context of help rather than technological issues

There are presentation issues and implementation issues

Designing User Support : Presentation issues How is help requested?

Command button function (on/off) separate application

How is help displayed? New window whole screen or split screen pop-up box hint icons

Designing User Support : Presentation issues

Effective presentation requires clear, familiar, consistent language instructional rather than descriptive language avoid of blocks of text summary and example

Designing User Support Systems : Implementation Issues Is help

OS command meta command application

What resources are available screen space memory capacity speed

Designing User Support Systems: Implementation Issues Structure of help data

single file file hierarchy database

Consider flexibility and extensibility hard copy browsing

Summary

Users require different support at different times

User support should be: available but unobtrusive accurate and robust consistent and flexible

User support comes in a number of styles: command-based, context sensitive help tutorial, online doc, wizards and assistants adaptive help

Design of user support must take account of: presentation and implementation issues