WebQual:

An

Instrument

for

Consumer

Evaluation

of

Web

Sites

ABSTRACT:

Despite

the

critical

need

to

know

how

consumers'

perceptions

of

Web

sites

influence

their

behavior,

and

especially

their

intention

to

revisit

or

purchase,

there

is

no

extant

general

measure

for

evaluating

Web

sites

and

no

consensus

on

what

such

an

instrument

should

measure.

The

authors

used

the

Theory

of

Reasoned

Action

and

the

Technology

Acceptance

Model

to

develop

the

WebQual

instrument

for

consumer

evaluation

of

Web

sites.

They

refined

it

through

a

literature

review

and

interviews

with

Web

designers

and

users,

and

tested

it

using

four

samples

of

Web

consumers.

WebQual

includes

dimensions

(informational

fit-to-task,

tailored

information,

trust,

response

time,

ease

of

understanding,

intuitive

operations,

visual

appeal,

innovativeness,

emotional

appeal,

consistent

image,

on-line

completeness,

relative

advantage)

and

shows

strong

measurement

validity.

It

is

a

highly

validated

instrument

that

can

provide

both

wide-and

fine-grained

measurements

of

organizational

Web

sites.KEY

WORDS

AND

PHRASES:

Consumer

evaluation,

instrument

development,

TAM,

Technology

Acceptance

Model,

Theory

of

Reasoned

Action,

TRA,

Web

site

evaluation.Web

sites

are

a

critical

component

of

the

rapidly

growing

phenomenon

of

ecommerce.

Worldwide,

business-to-consumer

retail

sales

netted

billion

in

Internet

retail

sales

are

expected

to

grow

to

billion

by

Web

sites

play

a

significant

role

in

the

overall

marketing

communication

mix

-they

complement

direct

selling

activities,

provide

supplemental

material

and

basic

company

information

to

customers,

and

project

a

corporate

image.

Businesses

are

eager

to

develop

means

for

measuring

and

analyzing

consumer

perceptions

of

Web

site

designs.Many

academic

researchers

studying

e-commerce

have

been

forced

to

develop

their

own

Web

evaluation

instruments

Given

the

amount

of

practitioner

interest

and

research

in

this

area,

a

well-validated,

generally

available

instrument

would

be

very

valuable.

It

is

time

for

the

IS

field

to

develop

such

an

instrument,

following

a

rigorous

and

comprehensive

development

method.

The

evolving

history

and

science

of

instrument

development

and

testing

in

behavioral

research

and

especially

in

IS

research

suggest

that

the

development

of

an

instrument

to

capture

consumers'

evaluations

of

a

Web

site

should

at

a

minimum

have

the

following

A

careful

review

of

the

literature

and

relevant

practice

to

identify

the

specific

constructs

that

should

be

part

of

the

measure.

Too

rapid

a

convergence

on

a

particular

set

or

framework

of

constructs

runs

the

risk

of

excluding

important

characteristics

of

the

phenomena.Out

of

this

comes

a

set

of

clearly

defined

and

distinct

constructs.

Multiple

questions

for

each

construct,

with

each

construct

being

unidimensional.

Since

error

is

common

to

all

measures,

multiple

LOIACONO,

WATSON,

AND

GOODHUE

questions

make

it

possible

to

assess

measurement

quality

and

to

address

measurement

problems

where

they

exist.

Adequate

discriminant

validity

tests

as

well

as

reliability

tests.

Reliability

without

discriminant

validity

can

mislead

developers

into

thinking

that

the

constructs

are

distinct

when,

in

fact,

they

are

not.

Samples

of

a

size

appropriate

to

the

statistical

techniques

used

for

assessing

measurement

validity.

A

test

of

nomological

or

predictive

validity.

It

is

necessary

to

know

that

the

measures

of

the

constructs

interact

in

reasonable

ways

with

other

constructs.If

consumer

evaluation

of

Web

sites

is

the

target

of

the

measurement

effort,

two

additional

requirements

must

be

The

focus

must

be

on

the

consumer's

reactions

to

many

specific

Web

sites,

and

not

on

e-commerce

or

Web

sites

in

general.

An

instrument

intended

for

this

purpose

must

be

tested

in

this

context.

The

scope

of

data

collection

must

include

reactions

to

many

different

Web

sites

(even

if

only

one

per

respondent).

Given

the

method

of

testing

for

discriminant

validity,

restricting

the

focus

to

a

single

Web

site

(even

if

evaluated

by

many

consumers)

will

surface

individual

differences

of

opinion

about

a

single

object,

rather

than

the

ability

of

the

instrument

to

accurately

track

the

dimensions

along

which

consumers

perceive

Web

sites

as

differing.An

instrument

whose

development

lacks

any

of

the

seven

characteristics

outlined

above

should

not

be

seen

as

a

validated

general-use

instrument

for

consumer

evaluation

of

Web

sites.

While

for

any

specific

development

effort

there

is

room

for

different

judgments

about

whether

the

first

characteristic

has

been

appropriately

met,

determining

compliance

for

the

other

conditions

is

fairly

straightforward.

Some

research

on

consumer

evaluations

of

Web

sites

has

been

published

(e.g.,

but

an

extensive

literature

review

found

no

study

that

met

all

the

conditions

described

above.More

specifically,

Schubert

and

Selz

developed

their

WA-Web

Assessment

tool

(www.businessmedia.org/businessmedia/businessmedia.nsf/pages/

based

on

the

three

phases

of

a

transaction

(information,

agreement,

and

settlement)

augmented

by

a

community

phase

Subsequent

research

extended

the

model

to

create

an

Extended

Web

Assessment

Model

(EWAM)

by

including

elements

of

TAM,

social

influence,

and

a

review

of

four

practitioner

reports

on

Web

evaluation

The

models

were

tested

with

samples

of

and

respondents,

respectively,

not

enough

for

a

careful

assessment

of

measurement

validity.In

another

customer-centric

endeavor,

Barnes

and

Vidgen

refined

a

measure

of

Web

site

quality

over

four

versions

Their

WQ

is

based

on

quality

function

deployment

Six

graduate

students

generated

the

initial

items,

too

narrow

a

base

for

establishing

content

validity.

The

samples

for

the

first

three

versions

were

small

and

respondents),

and

the

factor

struc-ture

varied

significantly

across

the

four

versions,

raising

questions

about

the

underlying

stability

of

the

initial

conceptualization.As

a

third

example,

Yoo

and

Donthu

developed

SITEQUAL

by

asking

students

in

two

marketing

classes

to

generate

appropriate

questions.

Fiftyfour

unique

items

were

generated,

and

they

were

the

basis

for

an

instrument

completed

by

students

for

three

self-selected

sites.

Although

the

sample

was

small,

exploratory

factor

analysis

(EFA)

was

used

to

reduce

the

instrument

to

items

and

nine

factors

of

two

broad

sets:

vendor-related

and

site

quality.

The

first

set

of

factors

was

removed

because

the

researchers

wanted

to

focus

on

site

quality.

An

instrument

measured

the

remaining

four

factors

(ease

of

use,

design,

processing

speed,

and

security).

Confirmatory

factor

analysis

(CFA),

apparently

using

the

same

data,

indicated

a

poor

fit

and

the

model

was

respecified.

After

several

iterations,

the

instrument

was

reduced

to

nine

items

to

measure

the

four

factors

(only

two

items

for

most

factors).

A

validation

study

with

subjects,

each

of

whom

evaluated

four

sites

(n

resulted

in

reliabilities

in

the

range

to

and

good

fit

indices.

In

the

authors'

view,

SITEQUAL's

original

set

of

items

was

too

narrowly

based,

and

most

of

its

final

factors

were

measured

by

only

two

items.It

is

also

instructive

to

look

at

the

articles

in

the

Information

Systems

Research

(ISE)

Special

Issue

on

Measuring

e-Commerce

Net-Enabled

Organizations

(June

and

September

Six

of

the

articles

in

this

double

issue

include

consumer

evaluations

of

Web

sites.

of

the

six

articles

meets

all

seven

conditions

outlined

Relative

to

condition

(coverage

of

appropriate

constructs),

a

comparison

of

the

constructs

targeted

in

the

six

measures

demonstrates

that

there

was

no

convergence

on

what

dimensions

should

be

measured,

as

shown

in

Appendix

Moreover,

as

also

shown

in

Appendix

of

the

measures

in

the

special

issue

of

ISR

has

the

breadth

and

coverage

of

the

measure

described

in

this

paper.In

fairness,

the

authors

of

the

ISR

articles

had

other

research

agendas,

and

of

them

took

as

a

primary

purpose

the

development

of

a

general

instrument

for

consumer

evaluation

of

Web

sites.

The

researchers

who

authored

the

articles

all

needed

a

measure

for

evaluating

Web

sites,

but

they

developed

different

measures.

Although

valuable

in

their

own

ways,

of

these

measures

has

the

focus

and

rigor

that

would

be

required

to

win

wide

acceptance

for

a

measure

of

a

construct

so

critical

in

research

and

practice.

If

a

carefully

developed

and

validated

general

measure

had

been

available,

these

researchers

(and

others)

would

have

been

able

to

focus

more

of

their

research

time

and

energy

on

their

research

agendas

rather

than

on

measurement

development.The

present

article

addresses

the

need

for

a

general

measure

of

consumer

evaluations

of

business-to-consumer

Web

sites.

The

instrument

it

describes,

WebQual,

has

been

reported

in

various

conference

papers,

but

there

has

been

no

published

description

of

its

careful

development

through

multiple

iterations

of

data

collection,

measurement

validity

analysis,

and

instrument

refinement.

Nevertheless,

as

evidence

of

the

demand

for

such

an

instrument,

there

have

been

more

than

requests

for

information

about

WebQual

from

researchers

and

companies,

and

it

has

already

been

cited

more

than

times

in

conferences,

workshops,

and

journals.One

cannot

evaluate

an

object

without

some

context.

Of

particular

concern

to

designers

of

Web

sites

is

the

question

of

whether

consumers'

reactions

to

a

Web

site

are

likely

to

induce

subsequent

visits

or

purchases

from

the

site

in

the

future

Thus

the

conceptual

context

used

in

developing

WebQual

was:

What

perceived

characteristics

of

a

Web

site

will

affect

a

consumer's

decision

to

reuse

the

site?The

IS

and

marketing

literature

were

drawn

upon

to

identify

the

specific

beliefs

important

to

predicting

consumer

reuse

of

a

Web

site.

In

addition,

exploratory

research

was

conducted

using

expert

judges.

An

initial

instrument

was

refined

through

three

different

versions.

At

each

step,

the

instrument's

measurement

validity

was

carefully

analyzed,

using

large

samples

and

students)

to

refine

the

conceptualization

and

the

questions.

The

final

version

contains

questions

on

characteristics

of

a

Web

site.

It

demonstrates

strong

measurement

validity,

and

it

predicts

intention

to

buy

from

or

revisit

a

Web

site.Research

FrameworkUsing

a

Web

site

can

be

both

an

IS

interaction

and

a

marketing

interaction

To

use

a

Web

site,

one

must

employ

computer

hardware

and

software

focused

on

information

storage,

display,

processing,

or

transfer.

In

addition,

many

aspects

relate

to

marketing

interactions.

Brand

and

company

images

affect

perceptions,

information

is

passed,

consumer

questions

are

answered,

and

purchases

are

made.

Therefore

both

IS

and

marketing

literature

were

employed

in

conceptualizing

the

way

consumers

evaluate

a

Web

site.The

Theory

of

Reasoned

Action

(TRA),

which

is

used

extensively

in

marketing

and

IS

research,

argues

that

individuals

evaluate

the

consequences

of

a

particular

behavior

and

create

intentions

to

act

that

are

consistent

with

their

evaluations

(see

top

of

Figure

Davis

applied

TRA

to

a

class

of

behaviors

that

can

be

loosely

defined

as

"using

computer

technologies,"

and

produced

the

Technology

Acceptance

Model

(TAM),

one

of

the

most

widely

cited

pieces

of

IS

research

Davis

argues

that

two

beliefs

are

predominant

in

predicting

the

behavior

of

using

computer

technologies:

perceived

ease

of

use

and

perceived

usefulness.

Through

an

extensive

stream

of

research,

Davis

and

others

have

developed

strong

measures

of

these

two

beliefs

and

demonstrated

their

predictive

power

in

a

number

of

contexts,

including

use

of

word

processors,

e-mail,

drawing

tools,

and

hospital

information

systems

.Davis

found

that

attitudes

did

not

completely

mediate

the

relationship

between

beliefs

and

intentions

(as

Fishbein

had

suggested),

and

argued

that

it

made

more

sense

to

focus

on

measuring

these

beliefs

as

direct

predictors

of

intentions

rather

than

trying

to

measure

attitudes

as

well.

Davis

also

initially

argued

that

in

the

context

of

using

computer

technologies

(at

least

in

the

domains

he

studied),

subjective

norms

did

not

seem

to

be

a

significant

predictor

of

intentions.There

is

some

disagreement

about

ignoring

social

norms

in

predicting

IS

use

(e.g.,

but

several

studies

have

successfully

excluded

social

norms,

focusing

only

on

ease

of

use,

usefulness,

trust,

and

so

forth,

as

predictors

of

e-commerce

use

Since

the

interest

here

is

in

whether

an

individual

will

use

a

specific

Web

site,

there

is

no

reason

why

subjective

norms

should

have

a

large

impact

on

behavior,

as

opposed

to

other

behaviors

where

norms

might

have

more

of

an

impact

(e.g.,

smoking

or

dieting).

For

the

most

part,

use

of

a

particular

site

is

a

private

affair,

not

visible

to

one's

peers.

Peer

pressure

might

encourage

an

individual

to

use

the

Web

in

general,

but

not

to

revisit

a

particular

Web

site.

Given

this

argument,

Davis's

findings,

and

the

need

to

contain

the

scope

of

the

research

to

a

reasonable

size,

social

norms

have

also

been

excluded

from

this

study.TAM

only

identifies

two

very

general

beliefs:

ease

of

use

and

usefulness

(see

middle

of

Figure

The

effort

to

develop

an

instrument

for

evaluating

Web

sites

begins

by

looking

both

beyond

and

within

ease

of

use

and

usefulness.

There

are

two

reasons

why

the

focus

is

not

narrowed

to

only

ease

of

use

and

usefulness.

First,

evidence

suggests

that

Web

use

is

driven

by

some

additional

factors

beyond

these

two.

In

particular,

Web

use

may

have

entertainment

value

that

is

not

easily

captured

by

ease

of

use

or

usefulness

For

this

reason

it

is

important

to

consider

the

possibility

of

adding

to

Davis's

two

general

constructs.Second,

following

Goodhue

and

Thompson,

an

instrument

for

evaluating

a

Web

site

will

be

most

useful

to

businesses

if

it

can

identify

in

more

detail

the

specific

aspects

that

make

the

Web

site

easy

to

use

or

useful

to

consumers

The

greater

clarity

of

detail

is

important

conceptually

because

some

aspects

may

be

found

empirically

to

be

more

important

than

others

in

determining

consumer

behavior.

This

is

significant

from

a

practical

business

standpoint

because

without

a

finer-grained

measure

than

ease

of

use

or

usefulness,

a

business

might

not

know

what

changes

to

make

in

a

Web

site

rated

low

in

usefulness.

It

is

necessary,

therefore,

to

consider

the

possibility

of

multiple

distinct

dimensions

of

ease

of

use

and

of

usefulness,

as

well

as

other

categories

of

beliefs,

such

as

entertainment,

which

together

predict

intention

to

reuse

a

Web

site

(see

bottom

of

Figure

).There

are

many

frameworks

for

thinking

about

measurement

validity.

The

frameworks

proffered

by

Bagozzi

and

by

Bagozzi

and

Phillips

are

used

in

this

paper

because

of

their

comprehensive

coverage

of

the

six

key

components

of

validity

shown

in

Table

which

are

explained

along

with

the

instrument

development

process

.The

overall

process

of

instrument

development

took

place

in

four

stages

that

together

address

all

of

Bagozzi's

validity

concerns.

The

process

also

meets

the

seven

requirements

stated

at

the

beginning

of

this

paper

for

a

general-purpose

measure

of

consumer

evaluations

of

Web

sites.

Table

(Requirements

and

four-pronged

effort

was

employed

more

or

less

simultaneously

to

determine

the

pertinent

dimensions

of

Web

site

evaluation

and

establish

content

validity.

First,

a

review

of

the

IS

and

marketing

literature

revealed

existing

constructs

related

to

Web

design

and

customer

satisfaction.

Popular

press

publications

were

also

examined

to

ensure

that

no

factor

was

overlooked

because

of

the

"newness"

of

the

Web.

In

parallel

with

this

effort,

three

exploratory

research

projects

ensured

the

comprehensiveness

of

the

constructs

relative

to

the

domain

of

the

Web:

soliciting

criteria

from

Web

surfers,

interviewing

professional

Web

designers,

and

studying

a

large

organization's

standards

for

Web

site

design.

Two

theoretical

perspectives

guided

the

effort

to

identify

all

the

relevant

distinct

constructs

that

might

affect

a

consumer's

intent

to

reuse

a

Web

site.

The

first

was

the

Technology

Acceptance

Model

As

explained

earlier,

an

effort

was

made

to

look

both

within

and

beyond

ease

of

use

and

usefulness.The

usefulness

realm

was

explored

more

deeply

by

utilizing

the

insight

from

task-technology

fit

that

a

technology

is

useful

when

it

fits

the

task

This

made

it

necessary

to

identify

the

tasks

a

Web

site

consumer

might

engage

Visitors

may

be

interested

in

several

of

these

categories

at

the

same

time

(e.g.,

entertainment

and

gathering

information),

but

conceptually

they

can

be

focused

on

separately

in

seeking

to

understand

the

way

a

Web

site

affects

a

consumer

engaged

in

that

task.Therefore

the

search

for

distinct

dimensions

for

evaluating

Web

sites

begins

with

a

framework

of

four

categories:

ease

of

use,

usefulness

in

gathering

information,

usefulness

in

carrying

out

transactions,

and

entertainment

value.•

Dimensions

Relating

to

Ease

of

Use.

The

literature

covers

not

only

the

traditional

idea

of

information

being

easy

to

read

and

understand

but

also

the

importance

of

ease

of

operation

(intuitive

operations)

and

navigation

(ease

of

understanding)

for

a

Web

site

Dimensions

Relating

to

Usefulness

in

Gathering

Information.

Regardless

of

the

information

search

activity,

certain

characteristics

of

the

process

emerge

as

important.

These

include

information

quality

and

the

ability

of

the

site

to

provide

the

consumer

with

tailored

information

through

such

things

as

search

fields

Dimensions

Relating

to

Usefulness

in

Carrying

Out

Transactions.

A

Web

site

must

support

the

consumer's

desire

to

carry

out

a

transaction

on-line.

The

site

must

meet

the

consumer's

functional

task

needs

(functional

fit-to-task)

and

expected

response

times

(response

time)

and

gain

the

consumer's

trust

The

customer

service

provided

by

a

firm

enhances

or

detracts

from

the

consumer's

ability

to

complete

the

task

Other

important

factors

are

the

ability

to

complete

necessary

transactions

on-line

(on-line

completeness)

the

relative

advantage

to

consumers

of

completing

transactions

over

the

Web,

as

compared

to

alternative

means

and

the

projection

of

a

consistent

company

image

across

all

points

of

contact

with

the

customer

Dimensions

Related

to

Entertainment

Value.

Finally,

some

consumers

seek

a

"full

experience"-they

want

to

be

entertained

by

the

process

of

searching.

Whether

they

make

a

purchase

or

not,

they

simply

enjoy

"strolling

down

the

aisles"

and

want

to

be

entertained

along

the

way.

For

these

consumers,

the

Web

site

must

create

a

pleasant

"experience."

It

must

be

visually

appealing

have

an

innovative

flare

separating

it

from

just

any

old

site

and

be

emotionally

appealing

so

as

to

encourage

continued

browsing

See

for

details

on

all

these

dimensions.The

literature

search

identified

constructs.

Related

to

ease

of

use

were

ease

of

understanding

and

intuitive

operations.

Related

to

gathering

information

were

information

quality

and

tailored

information.

Related

to

carrying

out

transactions

were

functional

fit-to-task,

trust,

response

time,

consistent

image,

on-line

completeness,

relative

advantage,

and

customer

service.

Related

to

entertainment,

visual

appeal,

and

innovativeness

was

emotional

appeal.

For

comparison

and

contrast,

Appendix

shows

the

constructs

measured

by

WebQual

and

by

five

articles

measuring

e-commerce

WebQual

surpasses

the

other

measures

in

terms

of

coverage

and

completeness.In

parallel

with

the

literature

review,

three

exploratory

research

projects

were

conducted

to

ensure

that

the

model

generated

was

comprehensive

and

that

items

were

drawn

both

from

the

literature

and

consumers.

This

approach

ensured

that

the

study

did

not

miss

any

key

aspect

that

had

not

yet

made

it

into

the

established

literature.First,

four

groups

of

about

students

each

(approximately

students

total)

were

asked

to

divulge

their

individual

ranking

criteria

for

high-versus

low-quality

Web

sites.

Each

group

ranked

Web

sites

within

one

of

four

product/service

categories:

CDs,

books,

hotel

reservations,

and

airline

reservations

Web

sites

in

all).

Of

particular

interest

for

this

project,

the

subjects

also

recorded

the

factors

that

in

their

view

differentiated

the

sites.

Two

judges

categorized

the

comments

into

higher-level

categories.Second,

mirroring

the

development

of

SERVQUAL,

practitioner

knowledge

was

also

tapped

to

ensure

that

no

key

factors

were

overlooked

Companies

are

concerned

with

what

their

customers

want

in

a

Web

site

and

have

developed

criteria

based

on

these

desires.

Using

telephone

interviews,

Web

designers

were

asked

to

explain

the

criteria

they

used

in

creating

Web

sites.Third,

along

the

same

lines,

the

Web

design

criteria

used

by

a

Fortune

company

were

studied.All

this

exploratory

research

lent

support

to

nine

of

the

WebQual

dimensions

uncovered

in

the

IS

and

marketing

literature:

tailored

information,

response

time,

ease

of

understanding,

intuitive

operations,

visual

appeal,

emotional

appeal,

consistent

image,

on-line

completeness,

and

relative

advantage.

Overlap

on

dimensions

arising

out

of

the

literature

and

the

exploratory

research

was

a

welcome

sign

that

the

research

effort

was,

in

fact,

comprehensive,

and

had

not

missed

any

critical

aspects

of

Web

site

evaluation.Finally,

a

review

of

research

performed

at

the

same

time

or

subsequent

to

the

initial

work

on

WebQual

reveals

that

other

researchers

concur

with

the

importance

of

particular

dimensions

identified

above

for

WebQual,

but

of

these

researchers

has

provided

as

complete

a

picture

as

WebQual.

This

further

confirms

the

relevance

of

the

total

set

of

dimensions

for

Web

site

evaluation:

information

quality

and

customer

service

.LOIACONO,

WATSON,

AND

GOODHUEEach

of

the

dimensions

is

assumed

to

be

a

distinct

construct

capable

of

varying

independently

from

the

others.

For

example,

a

Web

site

might

have

high

ease

of

understanding

on

each

page,

but

not

have

intuitive

operations,

thus

making

navigation

more

difficult.

This

is

a

total

disaggregation

model

Further,

the

overall

structure

of

a

Web

evaluation

is

conceptualized

as

bottom

up,

meaning

that

the

constructs

are

not

treated

as

"reflections"

of

some

single

underlying

overall

construct,

but

instead

the

overall

evaluation

is

seen

as

"produced

by"

the

combination

of

the

underlying

constructs

This

conceptualization

of

the

structure

requires

a

demonstration

that

the

measures

of

each

construct

are

distinct

(discriminant

validity)

even

if

they

are

correlated.Companies

conceivably

could

attempt

to

address

inadequacies

in

any

one

of

the

constructs

independently

of

the

others.

However,

the

link

between

aspects

of

Web

site

design

and

consumer

perceptions

might

be

more

straightforward

on

some

dimensions

(say,

response

time)

than

on

others

(say,

visual

appeal

or

emotional

appeal).All

but

one

of

the

identified

dimensions

for

evaluating

a

Web

site

can

be

assessed

after

a

single

visit

to

a

Web

site.

Only

customer

service

suggests

the

need

for

multiple

interactions

before

an

assessment

can

be

made.

In

fact,

customer

service

includes

both

one-time

interactions

with

a

company

via

the

Web

site

(e.g.,

obtaining

company

information)

and

multiple

interactions

(e.g.,

receiving

an

e-mail

response

following

an

inquiry).

In

order

to

restrict

the

scope

of

the

current

research

to

a

manageable

size,

customer

service

measures

requiring

multiple

interactions

were

not

included

in

the

initial

instrument.

Subsequent

research

could

then

focus

on

refining

the

dimensions

and

developing

measures

of

those

aspects

of

customer

service

not

assessable

after

a

single

visit.The

second

of

Bagozzi's

validity

concerns,

observational

meaningfulness

(see

Table

refers

to

the

extent

to

which

the

questions

(i.e.,

the

operationalizations)

actually

cover

all

relevant

aspects

of

the

concept

(content

validity)

and

whether

there

is

a

persuasive

reason

to

believe

there

is

a

link

between

the

questions

and

the

underlying

constructs

they

are

intended

to

measure.

Scale

development

can

be

either

deductive

or

inductive

Both

approaches

were

incorporated

through

an

extensive

literature

review

(inductive)

and

an

exploratory

research

phase

(deductive),

as

previously

described.An

initial

set

of

candidate

items

for

the

dimensions

was

developed

based

on

the

literature,

the

exploratory

research

with

Web

shoppers,

and

the

discussions

with

Web

developers.

This

was

done

by

carefully

reviewing

the

construct

definitions,

any

items

for

similar

constructs

from

published

research,and

the

comments

made

and

language

used

by

subjects

in

the

first

round

of

exploratory

research.

With

these

sources

in

mind,

appropriate

items

were

developed

to

match

the

construct's

definition,

with

the

goal

of

making

items

clear,

straightforward,

and

in

the

everyday

language

of

consumers.This

set

of

items

was

then

reduced,

using

an

approach

similar

to

the

one

used

by

Davis

in

his

pretest

of

measures

for

the

TAM

Twenty

Web

consumers

from

a

large

southeastern

university

graduate

students

and

undergraduates)

rated

the

items

on

how

well

they

corresponded

to

descriptions

of

the

four

higher-level

dimensions

of

a

Web

site

(ease

of

use,

usefulness,

entertainment,

and

complementary

(The

rankings

were

done

at

an

individual

level

with

no

collaboration

between

consumers.)

Items

that

ranked

lowest

were

discarded,

keeping

at

least

three

items

for

each

of

the

original

constructs.

This

resulted

in

an

initial

instrument

of

items

covering

constructs.The

students

who

participated

in

the

study

received

extra

course

credit.

Those

who

preferred

not

to

participate

could

receive

the

same

amount

of

extra

credit

by

writing

a

short

report

on

the

Web.

Many

students

opted

to

do

neither,

indicating

that

they

did

not

feel

coerced

to

participate.

The

participation

process,

and

all

the

other

elements

of

the

study,

was

approved

by

the

university's

human

subjects

committee.In

every

round,

the

subjects

were

given

a

context.

For

example,

they

might

be

told

"Imagine

it

is

your

friend's

birthday,

and

you

are

searching

for

a

good

gift-a

book."

They

would

then

be

told

to

explore

a

designated

Web

site

for

at

least

minutes

as

if

they

were

considering

which

book

to

buy

for

their

friend,

and

after

this

to

complete

the

questionnaire.

In

rounds

and

they

completed

the

survey

individually

in

a

lab

environment.

The

administrator

of

the

survey

reviewed

the

directions

with

each

group-explaining

that

they

were

to

indicate

their

level

of

agreement

for

each

statement

by

circling

the

appropriate

number

between

and

(strongly

disagree

to

strongly

agree)

and

reminding

them

that

this

was

to

be

done

individually.

In

rounds

and

subjects

were

given

written

instructions

and

allowed

to

complete

the

survey

individually

on

their

own

time.Twelve

different

Web

sites

were

used,

three

each

of

four

different

types:

books,

CDs,

hotels,

and

airlines

(see

Table

Both

service

and

product

sites

were

chosen

to

ensure

that

there

was

no

bias

to

either

type

of

site.

CD

and

book

sites

are

obvious

categories

for

students.

For

this

student

population

(a

fairly

affluent

group),

airline

and

hotel

sites

were

also

appropriate.

Many

of

the

students

travel

via

airplane

to

their

homes,

and

others

indicated

that

they

used

the

Web

to

plan

spring

break

trips.

Any

students

who

had

not

actually

used

the

Web

to

make

hotel

or

airline

reservations

certainly

knew

others

who

had

and

could

easily

identify

with

the

task.

Since

the

object

of

interest

included

not

only

consumers

who

had

made

a

Web

purchase,

but

those

who

were

potential

Web

purchasers,

it

was

appropriate

to

include

all

four

types

of

Web

sites.

The

specific

sites

were

chosen

for

their

variability,

based

on

LOIACONO,

WATSON,

AND

GOODHUE

rankings

of

specific

Web

sites

generated

by

subjects

in

the

earlier

exploratory

research

phase.Stage

Refining

the

InstrumentItem-order

bias

was

prevented

by

creating

two

random-order

versions

of

the

initial

instrument.

To

prevent

inflating

reliabilities

from

artificially

high

correlations

where

subjects

answered

adjacent

questions

using

anchoring

and

adjustment,

multiple

items

pertaining

to

a

single

construct

were

separated

from

each

other.

Items

were

measured

on

a

seven-point

Likert

scale.

Reversescored

items

were

included

to

keep

respondents

alert

while

completing

the

survey

and

to

eliminate

response

bias

.Since

there

were

questions

in

the

initial

questionnaire,

and

the

rule

of

thumb

for

factor

analysis

calls

for

at

least

five

times

as

many

observations

as

there

are

variables

to

be

analyzed,

at

least

subjects

were

required

In

round

data

were

collected

from

undergraduates

enrolled

in

an

introductory

IS

course.

The

specific

characteristics

of

each

round

of

data

collection

are

listed

in

Table

The

ages

and

genders

of

the

subjects

matched

closely

with

those

of

the

largest

group

of

Internet

to

years

old,

approximately

percent

female

and

percent

male

.The

data

analysis

and

purification

phase

of

the

study

was

guided

by

the

recommended

procedure

for

instrumental

development

The

first

pass

of

data

analysis

and

purification

was

intended

to

improve

measurement

validity

by

identifying

and

removing

the

worst-performing

items.

First,

items

that

reduced

the

reliability

(Cronbach's

alpha)

of

any

of

the

constructs

were

deleted

and

the

process

continued

until

no

item's

removal

improved

a

construct's

overall

alpha.

The

end-result

was

the

removal

of

items.

Second,

items

found

to

possess

low

correlations

with

similar

traits

(i.e.,

less

than

were

removed

from

the

instrument.

This

followed

the

modified

multitraitmultimethod

process

of

item

deletion

as

described

by

Goodhue

A

total

of

items

were

deleted

during

this

phase.

The

final

step

consisted

of

removing

items

that

appeared

to

have

serious

discriminant

validity

problems.

Items

were

removed

if

they

correlated

much

more

highly

with

items

measur-

ing

different

constructs

than

with

items

in

their

intended

construct

Under

these

criteria,

eight

items

were

deleted.

Following

Straub,

no

effort

was

made

to

remove

all

violations

of

Campbell's

discriminant

validity

rule,

since

spurious

correlations

can

occur

by

chance

in

such

a

large

correlation

matrix

Further,

as

planned,

more

precise

means

of

detecting

discriminant

validity

problems

would

be

employed

in

future

rounds.

In

particular,

an

effort

was

made

to

note

possible

discriminant

validity

problems

between

information

quality

and

functional

fit-to-task.

Given

the

strong

conceptual

arguments

for

the

distinctness

of

these

constructs,

they

were

not

collapsed

at

this

time,

and

the

second

round

would

show

whether

the

problems

continued.After

items

were

deleted,

each

construct

was

reviewed

to

ensure

that

at

least

five

items

per

construct

remained.

(If

measurement

validity

problems

were

discovered

in

future

founds,

this

would

make

it

possible

to

drop

up

to

two

items

for

each

construct

and

still

have

at

least

three

items

per

construct.)

For

constructs

that

were

underrepresented,

additional

items

closely

related

to

the

remaining

items

were

generated

by

the

researchers,

keeping

in

mind

the

conceptual

definitions

of

the

constructs

and

the

language

used

by

consumers

in

the

exploratory

studies.

Twenty-seven

items

were

added,

resulting

in

an

instrument.In

round

data

were

collected

from

undergraduate

students

(see

Table

A

two-step

process

was

employed

to

select

the

questions

to

be

included

in

the

next

version

and

make

an

initial

test

of

their

validity.Selection

of

Best

Questions

for

Each

Dimension.

Since

a

construct

should

have

at

least

three

items,

and

lengthy

questionnaires

typically

have

a

lower

response

rate,

it

was

decided

to

include

only

the

top-three

items

loading

on

each

construct

in

the

final

questionnaire

Notes:

df

degrees

of

freedom,

RMSEA

root

mean

square

error

of

approximation,

SRMR

standardized

root

mean

square

residual,

RNI

relative

noncentrality

index

(equivalent

to

CFI),

NNFI

non-normed

fit

index

(equivalent

to

TLI).

Only

constructs

were

included

in

Round

Emotions

were

not

included.conducted

as

a

rapid

way

to

identify

the

questions

with

the

greatest

central

tendencies

for

their

constructs.

For

each

of

the

constructs,

the

three

questions

loading

highest

on

their

factors

were

chosen.

Although

eight

of

the

constructs

loaded

on

separate

factors,

as

had

been

hoped,

five

constructs

(information

quality,

functional

fit-to-task,

tailored

information,

innovativeness,

and

relative

advantage)

did

not,

at

least

in

the

EFA.

This

might

have

been

indicative

of

discriminant

validity

problems,

but

that

was

not

an

important

concern

at

this

point

for

two

reasons.

In

the

first

place,

EFA

is

unstable,

especially

when

it

contains

many

marginal

questions.

As

Bagozzi

and

Phillips

have

shown,

EFA

has

serious

deficits

in

assessing

discriminant

validity

Not

only

is

there

no

explicit

statistical

test

that

can

be

used,

but

the

factor

loadings

are

unpredictable

and

can

be

quite

misleading.

Bagozzi

and

Phillips

give

an

example

where

an

EFA

collapsed

factors

that

were

shown

to

be

distinct

in

a

Confirmatory

Factor

Analysis

(CFA),

similar

to

the

present

results

pp.

Second,

as

previously

planned,

a

CFA

analysis

(a

much

more

powerful

test

of

discriminant

validity

than

EFA)

would

soon

be

used

on

the

remaining

questions.Discriminant

Validity:

Round

The

overall

fit

of

the

model

was

tested

by

confirmatory

factor

analysis

(using

AMOS).

For

an

overall

test

of

discriminant

validity,

following

Anderson

and

Gerbing

and

also

Bagozzi

and

Phillips,

the

discriminant

validity

of

each

of

the

possible

pairs

of

the

constructs

was

tested

individually

For

each

pair,

the

fit

of

the

full

model

was

compared

with

the

fit

of

a

model

that

was

exactly

the

same

except

for

collapsing

the

pair

of

constructs

into

one

construct.

More

specifically,

for

the

collapsed

model,

the

two

target

constructs

were

constrained

to

have

a

correlation

of

and

equal

correlations

with

the

other

constructs.

The

general

idea

is

illustrated

in

Figure

Since

the

full

model

and

the

collapsed

model

are

"hierarchically

nested,"

a

chi-square

difference

test

makes

it

possible

to

see

whether

relaxing

the

restriction

results

in

a

statistically

significant

improvement

in

the

fit

.With

so

many

comparisons

possible

pairs)

and

a

significance

level

of

it

would

be

possible

for

random

variations

to

influence

the

results

at

least

in

some

cases.

Therefore,

in

interpreting

the

results,

consistent

with

Anderson

and

Gerbing,

it

was

resolved

that

"respecification

decisions

should

not

be

based

solely

on

statistical

considerations

alone,

but

rather

in

conjunction

with

theory

and

content

considerations.

[This]

reduces

the

possibility

of

taking

advantage

of

sampling

error

to

attain

goodness

of

fit"

p.

In

addition,

the

data

sets

from

rounds

and

could

be

used

to

confirm

assessments

of

discriminant

validity.Every

possible

pair

of

constructs

was

found

to

be

distinct

at

the

level

of

significance,

with

one

exception:

response

time

versus

intuitive

operations.

This

pair

missed

the

significance

cutoff

(χ

df

p

Because

these

two

constructs

were

so

different

conceptually,

it

seemed

unwise

to

conclude

that

they

were

a

single

concept,

and

both

were

retained

for

further

testing.

As

will

be

seen,

the

analysis

of

the

data

from

rounds

and

vindicated

this

faith

in

the

discriminant

validity

of

these

two

constructs.Statistical

significance

in

discriminant

validity

tests

does

not

necessarily

imply

that

the

distinction

between

constructs

is

practically

significant

Vandenberg

and

Lance

address

this

concern

by

proposing

that

in

addition

to

looking

at

chi-square

differences

between

the

nested

models

as

the

definitive

test,

researchers

might

also

look

at

changes

in

the

comparative

fit

index

(CFI)

They

suggest

that

an

improvement

of

or

more

in

the

CFI

is

a

definite

indication

of

the

practical

significance

of

discriminant

validity.This

approach

was

not

used

because

of

a

feeling

that

Vandenberg

and

Lance's

approach

was

biased

toward

smaller

models,

where

a

local

improvement

was

more

likely

to

have

a

noticeable

affect

on

overall

fit.

Therefore,

for

the

tests

of

practical

significance,

the

four

pairs

of

constructs

with

the

highest

correlations

were

looked

at,

and

each

pair

was

tested

in

isolation

(i.e.,

two

constructs

and

six

questions).

The

testing

followed

Vandenberg

and

Lance's

suggestion

that

CFI

should

increase

by

at

least

for

the

discriminant

valid-Figure

Fixed

vs.

Relaxed

Model

Comparison

for

Assessing

Discriminant

Validityity

to

be

"practically

significant"

In

these

tests,

three

of

the

four

pairs

achieved

an

improvement

in

CFI

of

or

greater

(information

quality

and

tailored

communication,

on-line

completeness

and

relative

advantage,

visual

appeal

and

innovativeness),

and

one

pair

(information

quality

and

functional

fit-to-task)

did

not

(change

in

CFI

of

Recall

that

there

were

similar

concerns

about

the

discriminant

validity

of

these

two

constructs

based

on

the

analysis

of

the

round

data.

Reexamining

the

questions

and

the

definitions

of

these

two

constructs

led

to

the

conclusion

that

in

fact

there

was

quite

a

bit

of

overlap

and

little

practical

significance

in

maintaining

them

as

separate

constructs.

Therefore,

they

were

collapsed

into

a

single

construct.All

together,

the

round

analyses

reduced

WebQual

from

to

constructs,

and

from

to

questions.

See

Appendix

for

the

final

items

by

construct.A

complete,

confirmatory

assessment

of

the

measurement

validity

of

the

final

version

of

the

questionnaire

was

performed

with

two

new

samples,

round

containing

students

collected

in

the

summer/fall

time

frame

and

round

containing

students

collected

in

the

time

With

these

two

new

samples,

all

the

empirically

testable

concerns

suggested

by

Bagozzi

in

Table

were

addressed

(the

last

four

rows).

Table

displays

the

overall

fit

of

the

CFA

measurement

model

(using

AMOS),

for

round

round

and

round

The

four

recommended

fit

indices

for

all

the

rounds

indicate

quite

acceptable

fit

for

the

final

version

The

standardized

item

loadings

on

their

constructs

ranged

from

to

However,

all

but

two

in

round

and

all

but

one

in

round

were

or

above.

These

results

indicate

strong

support

for

the

overall

fit

of

the

model.

Correlations

for

the

constructs

in

rounds

and

are

found

in

Appendix

reliability

of

the

final

questionnaire

constructs

with

three

questions

each)

was

calculated

using

Cronbach's

alpha

As

Table

shows,

for

round

the

alphas

of

the

constructs

ranged

from

to

with

of

the

constructs

having

an

alpha

greater

than

Of

the

two

remaining

constructs,

one

had

an

alpha

of

and

one

had

an

alpha

of

The

results

were

almost

identical

for

round

Since

the

suggested

hurdle

value

for

frequently

used

instruments

ranges

from

alpha

levels

of

to

all

were

above

the

more

generous

hurdle

of

and

only

two

constructs

(on-line

completeness

and

tailored

communications)

were

slightly

below

the

more

restrictive

hurdle.Discriminant

validity

was

checked

separately

for

round

and

round

All

possible

pairs

of

the

remaining

constructs

possible

pairs

from

constructsin

round

and

possible

pairs

from

constructs

in

round

were

tested

to

see

if

fit

was

improved

when

any

pair

was

collapsed

into

a

single

construct,

using

the

same

approach

as

described

for

round

Again

it

was

recognized

that

with

so

many

tests

in

the

two

rounds)

some

would

fail

to

achieve

significance

through

random

chance.Recall

that

the

pair

comprising

response

time

and

intuitive

operations

had

not

quite

achieved

discriminant

validity

in

round

In

the

round

data,

these

two

constructs

were

shown

to

be

distinct

at

the

level

of

significance.All

other

pairs

of

constructs

in

round

were

distinct

at

least

at

the

level

of

significance,

with

two

exceptions:

innovativeness

versus

emotional

appeal,

and

information

fit-to-task

versus

tailored

information.

In

tests

of

the

round

data,

all

pairs

of

constructs

were

distinct

at

the

level

of

significance,

with

one

exception-visual

appeal

and

innovativeness-which

missed

significance

To

summarize

the

round

round

and

round

discriminant

validity

results,

out

of

pair

tests

across

three

rounds

of

data,

showed

statistically

significant

discriminant

validity,

and

four

missed

achieving

significance.

Even

for

those

four

pairs

of

constructs,

each

pair

showed

statistically

significant

discriminant

validity

in

at

least

two

of

the

three

rounds

of

tests.Finally,

the

data

from

rounds

and

were

put

together,

repeating

the

chi

square

difference

tests

for

discriminant

validity.

All

pairs

of

constructs

were

distinct

(p

All

in

all,

it

can

be

confidently

stated

that

the

constructs

are

separate

characteristics

of

a

Web

site

in

the

minds

of

consumers.Strictly

speaking,

convergent

validity

(à

la

Bagozzi)

refers

to

the

correlation

between

the

new

measure

and

a

second

"maximally

different"

measure

of

the

same

construct

For

example,

a

measure

of

performance

using

managerial

perceptions

might

be

compared

to

an

objective

measure

of

performance

or

to

some

other

already

accepted

measure

of

performance

as

a

way

to

validate

the

new

measure.

Since

there

were

constructs,

it

would

be

necessary

to

find

alternative

measures

for

all

constructs.

This

has

not

been

done,

to

date.

More

general

measures

of

convergent

validity

are

possible.

Following

the

example

of

the

development

of

SERVQUAL

subjects

were

asked

one

additional

question

evaluating

the

overall

Web

site-"Overall,

how

would

you

rate

the

quality

of

this

Web

site?"

scale

anchored

on

"poor"

and

"excellent").

The

word

"quality"

is

associated

with

such

words

as

"goodness,"

"excellence,"

"value,"

and

"worth"

in

Roget's

Thesaurus

and

thus

this

single

question

captures

the

central

essence

of

a

consumer's

overall

evaluation

of

a

Web

site.The

total

WebQual

score

items)

was

computed

and

then

compared

to

the

overall

Web

site

question.

The

two

were

correlated

at

(p

giving

an

overall

and

very

general

indication

of

convergent

validity.Nomological

validity

is

the

ability

of

a

new

measure

to

perform

as

expected

in

a

network

of

known

causal

relations

and

well-established

measures

One

cannot

have

confidence

in

a

measure

if

it

does

not

behave

in

a

reasonable

fashion

in

relation

to

other

accepted

constructs.

In

the

case

of

WebQual,

a

relevant

demonstration

of

nomological

validity

would

be

the

extent

to

which

constructs

that

have

been

conceptually

linked

to

Web

site

use

(in

this

and

other

research

papers)

do

actually

predict

a

Web

visitor's

behavioral

intention

in

ways

that

are

consistent

with

current

knowledge

and

expectations.One

way

to

test

WebQual's

ability

to

predict

consumer

intentions

would

be

to

regress

the

constructs

on

intent

to

reuse/purchase.

However,

since

some

of

the

constructs

are

highly

correlated,

multicollinearity

would

be

a

problem

with

a

regression

analysis

of

this

kind.The

multicollinearity

problem

can

be

side-stepped

by

a

second-order

factor

analysis

in

advance

of

looking

at

the

structural

links

between

the

second-order

factors

and

intent

to

reuse.

Because

this

is

a

significant

piece

of

research

in

its

own

right,

it

is

beyond

the

scope

of

the

current

study.

However,

one

can

take

advantage

of

such

an

analysis

to

give

the

groupings

and

loadings

from

the

underlying

constructs

to

five

second-order

constructs

The

underlying

and

five

second-order

constructs

are

shown

at

the

left-hand

side

and

middle

of

Figure

with

the

loadings

being

the

single

numbers

next

to

arrows.

As

can

be

seen,

the

first-order

factors

resolve

into

five

second-order

factors:

usefulness,

trust,

response

time,

ease

of

use,

and

These

groupings

and

loadings

were

used

to

analyze

the

links

to

intention

for

three

separate

datasets:

round

(spring

N

round

(summer/fall

N

and

round

N

All

fit

indices

were

found

to

be

acceptable

(see

Table

).Intention

to

reuse/purchase

was

measured

using

the

questions

shown

in

Appendix

Note

the

expansion

from

the

use

of

two

indicators

in

rounds

and

(Cronbach's

alpha

of

and

respectively)

to

five

indicators

in

round

(Cronbach's

alpha

of

The

two-indicator

measure

and

the

fiveindicator

measure

are

both

quite

adequate.

The

different

measures

were

notcombined

into

a

single

analysis,

but

were

considered

to

be

roughly

equivalent

for

the

nomological

validity

analysis.

Figure

and

Table

show

the

results

of

the

estimated

causal

links,

by

displaying

three

numbers

for

each

causal

path,

corresponding

to

the

spring

The

importance

of

usefulness

is

consistent

with

findings

by

Davis

and

others.

The

importance

of

entertainment

is

also

consistent

with

previous

research

The

appearance

of

trust

and

response

time

as

dimensions

reveals,

as

was

suggested

at

the

beginning

of

this

paper,

that

Web

use

has

predictors

beyond

the

usefulness

and

ease

of

use

suggested

by

TAM.

The

results

suggest

the

intriguing

possibility

that

the

relative

importance

of

entertainment

may

be

increasing

over

time.

If

these

shifts

are

confirmed

by

future

research,

one

explanation

might

be

that

the

response

time

in

the

earlier

data

was

a

factor

of

less

mature

technologies

and

over

several

years

became

much

less

of

a

factor.Although

trust

has

a

significant

link

to

reuse

in

round

the

lack

of

that

link

in

rounds

and

is

somewhat

surprising.

One

possible

explanation

is

that

with

more

experience

and

a

higher

rate

of

Web

purchases

in

the

later

time

period,

these

consumers

were

more

likely

to

have

encountered

Web

sites

where

trust

is

an

issue,

and

thus

were

more

sensitized

to

it.

Perhaps

consumers

are

more

aware

today

than

they

were

several

years

ago

of

the

danger

of

purchasing

at

untrustworthy

Web

sites,

but

since

this

was

not

hypothesized,

it

is

merely

speculation

at

this

point.The

lack

of

a

positive

linkage

between

ease

of

use

and

intent

to

reuse

is

not

totally

unexpected.

It

is

consistent

with

the

findings

of

Davis

and

other

that

for

experienced

users,

ease

of

use

is

not

a

direct

predictor

of

intent

to

reuse

significance

at

significance

at

significance

at

significance

at

is

a

predictor

of

usefulness

As

shown

at

the

bottom

of

Table

the

subjects

were

quite

experienced-they

had

many

years

of

experience

on

the

Web.

Although

the

significant

negative

link

between

ease

of

use

and

reuse

in

round

is

surprising,

it

is

consistent

with

a

multicollinearity

relationship

between

ease

of

use

and

usefulness-these

two

constructs

are

highly

correlated

with

each

other

and

both

are

quite

correlated

with

reuse.

In

this

case,

the

negative

link

in

round

should

not

be

viewed

as

a

causal

link.

Because

ease

of

use

is

still

an

important

construct,

and

consistent

with

the

findings

of

Davis

and

his

colleagues,

the

link

between

ease

of

use

and

usefulness

has

been

included

in

the

present

analysis

and

is

shown

in

Figure

and

the

middle

portion

of

Table

Overall,

these

results

are

strong

positive

confirmation

of

nomological

validity.DiscussionThe

primary

research

contribution

is

the

development

of

a

validated

instrument

for

evaluating

Web

sites

by

following

a

more

rigorous

process

than

predecessors

and

revealing

a

wider

range

of

dimensions.

Measurement

instruments

are

in

a

very

real

sense

a

research

"infrastructure."

The

development

of

the

measure

in

itself

may

do

little

to

prove

or

disprove

a

specific

hypothesized

relationship,

and

so

may

not

move

theory

forward

very

much.

However,

when

an

important

domain

figures

prominently

in

a

variety

of

research

programs,

the

development

of

a

more

effective

measurement

instrument

moves

many

research

programs

forward.

As

noted

earlier

in

this

paper,

five

articles

in

a

recent

special

issue

of

ISR

developed

instruments

to

measure

user

reactions

to

Web

sites,

and

of

these

measures

met

the

suggested

requirements

for

a

general

purpose

instrument

to

capture

consumer

evaluations

of

a

Web

site.

When

there

is

no

carefully

developed

and

tested

general-purpose

instrument

available,

each

researcher

is

forced

to

spend

research

time

and

effort

on

developing

a

measure,

with

the

result

that

measures

are

weaker,

and

researcher

time

is

drawn

away

from

the

theoretical

interest

of

the

research.The

importance

of

instrument

development

in

research

is

easily

seen

by

looking

at

the

citation

counts

of

three

papers

introducing

two

prominent

measurement

instruments:

User

Information

Satisfaction

and

SERVQUAL

These

three

papers

focused

almost

exclusively

on

the

development

and

testing

of

the

two

instruments,

not

on

theory

testing.

According

to

the

Web

of

Science,

the

paper

by

Bailey

and

Pearson

has

been

cited

times,

the

one

by

Ives,

Olson,

and

Baroudi

has

been

cited

times,

and

the

one

by

Parasuraman,

Zeithaml,

and

Berry

has

been

cited

times.

These

instruments

have

had

a

huge

impact

on

the

research

community.A

second

contribution

is

that,

by

starting

with

TAM

and

looking

both

within

and

beyond

the

original

constructs

of

usefulness

and

ease

of

use,

this

paper

demonstrates

how

to

apply

that

theory

base

to

additional

technology

contexts.

This

approach

may

be

valuable

as

new

information

technologies

appear

on

the

scene

(Web-enabled

handheld

devices,

navigation

systems,

etc.)

As

this

LOIACONO,

WATSON,

AND

GOODHUE

evolution

occurs,

so

will

the

need

for

IS

and

marketing

research

to

meld

in

order

to

measure

the

effectiveness

of

the

new

devices.

WebQual

stands

as

a

significant

contribution

to

the

current

marketing

and

IS

literature.A

third

research

contribution

is

WebQual's

comprehensive

scope,

which

takes

in

the

many

different

factors

that

contribute

to

the

reuse

of

Web

sites.

This

facilitates

at

least

a

first

attempt

at

discerning

their

relative

importance.A

poor

Web

site

can

cause

bad

press,

customer

dissatisfaction,

and

even

customer

loss

WebQual

offers

practitioners

a

validated

reliable

instrument

for

evaluating

Web

sites.

The

items

provide

a

valuable

and

accurate

measure

of

constructs

that

affect

consumer

intention

to

purchase

and

revisit,

a

critical

pragmatic

indicator

of

a

site's

value.

Companies

can

use

WebQual

to

"consumer

test"

sites

under

development

and

detect

which

elements

need

improvement

prior

to

public

release.

Given

the

investment

many

companies

make

in

their

Web

sites,

a

cost-effective

instrument

for

comparing

design

alternatives

should

have

substantial

practical

value.Both

purely

Web-based

and

click-and-mortar

companies

can

gain

from

conducting

a

WebQual

analysis.

For

example,

a

click-and-mortar

firm

such

as

Barnes

and

Noble

can

benefit

from

understanding

how

effective

each

aspect

of

its

Web

site

is,

and

so

too

does

Amazon,

a

purely

Web-based

competitor.

The

two

companies

have

different

Web

strategies,

but

both

gain

from

knowing

how

well

they

rate

on

the

basic

Web

site

evaluation

constructs,

such

as

intuitive

operations

and

informational

fit

to

task.

In

addition,

WebQual

also

serves

as

a

means

of

benchmarking

against

competitors.

Barnes

and

Noble

may

determine,

given

its

business

strategy,

that

it

is

willing

to

score

lower

on

certain

components

of

WebQual,

such

as

relative

advantage,

but

not

on

on-line

completeness

or

consistent

image.One

of

the

values

of

WebQual

is

that

it

provides

a

fine-grained

analysis

of

a

site's

shortcomings.

While

an

instrument

based

on

TAM

might

be

able

to

diagnose

a

shortfall

on

ease

of

use,

WebQual

will

indicate

whether

the

ease

of

use

problem

arises

from

problems

with

ease

of

understanding

or

with

intuitive

operations.

Knowing

that

a

Web

site

is

lacking

on

a

particular

dimension

would

give

the

company

a

clearer

focus

for

corrective

action.WebQual's

development

was

based

on

the

responses

of

undergraduate

business

students

to

a

selected

group

of

Web

sites.

These

subjects

were

typical

of

a

substantial

body

of

Web

consumers

but

were

not

necessarily

representative

of

all

consumers.

Furthermore,

many

of

the

subjects

were

not

ongoing

customers

of

the

sites

selected

for

assessment.

However,

firms

are

interested

both

in

servicing

existing

customers

and

in

attracting

new

customers,

so

they

need

an

instrument

that

is

valid

for

both

groups.

These

important

limitations

INTERNATIONAL

JOURNAL

OF

ELECTRONIC

COMMERCE

are

typical

of

those

facing

most

instrument

developers

because

such

work

often

needs

to

start

in

an

environment

where

many

subjects

are

readily

and

repeatedly

available.

Future

research

can

explore

the

implications

for

Web

site

quality

with

after-sales

service

quality

added.

Further

confirmatory

research

needs

to

be

done

with

broad

samples

of

consumers

for

a

range

of

Web

sites.

Also,

while

WebQual

indicates

where

a

site

may

have

deficiencies,

follow-up

research

is

needed

that

focuses

on

the

link

between

the

specific

changes

that

can

be

made

to

a

Web

site

and

the

resulting

changes

in

customer

perceptions.

Given

that

WebQual

has

completed

initial

development

and

refinement,

it

is

now

appropriate

to

investigate

some

other

important

issues,

such

as

business-to-business

and

noncommercial-to-consumer

sites

In

addition,

new

technologies

are

ever

expanding

and

broadening

the

capabilities

of

Web

sites.

Subsequent

WebQual

research

will

need

to

fold

in

additional

elements,

such

as

audio,

video,

and

mobile

Web

applications

Other

tasks

beyond

information

gathering,

as

used

in

this

study,

may

reveal

a

different

breakdown

of

the

constructs.

For

example,

information

quality

and

functional

fit-to-task

may

not

combine

as

they

did

in

this

research.Finally,

the

study

looks

at

traditional

uses

of

the

Web

to

convey

information

and

facilitate

transactions.

However,

other

ways

to

utilize

the

Web

are

evolving,

such

as

networking

and

blogging.

These

types

of

activities

are

not

the

focus

of

the

current

WebQual

research

but

may

be

included

in

future

research.This

study

shows

how

the

TRA

and

TAM

can

be

applied

to

a

new

domain,

thereby

enabling

us

to

see

the

relative

importance

of

many

different

characteristics

in

predicting

reuse

of

a

Web

site.

Its

major

contribution,

however,

is

in

providing

useful

"research

infrastructure"

for

the

domain

of

the

electronic

market

space.

In

the

age

of

the

Internet

and

electronic

commerce,

IS

and

marketing

researchers

and

practitioners

need

a

means

of

assessing

Web

sites.

The

research

effort

described

in

this

paper

has

produced

a

valid

and

reliable

instrument

for

consumer

evaluations

of

Web

sites.

WebQual

can

be

freely

used

by

academics

without

permission.

It

should

be

able

to

support

a

wide

range

of

important

IS

and

marketing

studies

as

researchers

attempt

to

understand

a

variety

of

issues

related

to

the

electronic

market

space.

Although

individual

researchers

may

focus

on

somewhat

different

issues,

and

may

need

to

develop

one

or

more

supplemental

measures

for

their

own

specialized

constructs,

the

existence

of

a

validated

baseline

measure

should

be

a

major

advantage.

It

provides

a

starting

point

that

will

speed

and

enhance

the

quality

of

measurement

for

many

studies.

In

addition,

to

the

extent

that

researchers

converge

on

standard

measures,

it

will

be

much

easier

to

compare

and

consolidate

findings

across

studies.Of

course,

WebQual

is

not

the

final

word

in

measurement

instruments

for

Web

sites.

Like

any

measurement

instrument

for

an

important

research

domain,

it

will

certainly

be

modified,

added

to,

and

refined

in

various

ways.

A

selection

of

MIS

graduate

and

undergraduate

students,

each

of

whom

had

at

least

some

experience

on

the

All

the

items

in

all

the

questionnaires

in

all

the

research

domains

were

originally

generated

by

the

researchers.

For

this

study,

items

generated

after

round

were

tested

and

validated

by

three

additional

data-collection

One

company

raised

concerns

about

the

questions

for

emotional

appeal

("I

feel

happy

"I

feel

cheerful

etc.),

so

a

different

approach

was

adopted

in

round

The

new

questions

did

not

perform

well,

so

the

old

questions

were

restored.

However,

the

emotional

measures

are

missing

from

the

analyses

for

round

The

emotional

appeal

questions

were

excluded

from

the

analysis

for

round

because

their

wording

had

changed

for

that

round.

However,

this

construct

was

found

to

be

significantly

different

from

the

other

constructs

in

rounds

and

Note

that

this

is

distinct

from

reliability,

which

assesses

whether

all

items

of

a

particular

construct

correlate

strongly

with

other

"maximally

similar"

items,

and

by

assumption,

with

the

underlying

AMOS

was

used

to

assess

the

structural

model,

and

all

first-order

constructs

were

allowed

to

be

According

to

a

personal

conversation

between

one

author

and

John

Neter,

multicollinearity

is

strongly

indicated

when

one

variable

is

a

strong

regression

predictor

of

another,

but

adding

an

additional

independent

variable

to

the

regression

causes

the

sign

of

the

relationship

to

change.

This

was

exactly

the

case

with

ease

of

use.

A

regression

without

usefulness

shows

a

strong

link

significant

at

between

ease

of

use

and

reuse.

Adding

usefulness

to

the

regression

causes

the

link

between

ease

of

use

and

reuse

to

completely

reverse

its

direction

significant

at

This

is

strong

evidence

that

the

apparent

negative

link

is

due

to

multicollinearity

and

is

not

a

true

causal

Aaker,

D.A.,

and

Stayman,

D.M.

Measuring

audience

perceptions

of

commercials

and

relating

them

to

ad

impact.

Journal

of

Advertising

Research,

Agarwal,

R.,

and

Karahanna,

E.

Time

flies

when

you're

having

fun:

Cognitive

absorption

and

beliefs

about

information

technology

usage.

Management

of

Information

Systems

Quarterly,

Agarwal,

R.,

and

Venkatesh,

V.

Measuring

factors

that

influence

the

success

of

Internet

commerce.

Information

Systems

Research,

Ajzen,

I.,

and

Fishbein,

M.

Understanding

Attitudes

and

Predicting

Social

Behavior.

Englewood

Cliffs,

NJ:

Prentice

Hall,

Anderson,

J.C.,

and

Gerbing,

D.W.

Structural

equation

modeling

in

practice:

A

review

and

recommended

two-step

approach.

Psychological

Bulletin,

Babbie,

E.

Commerce,

Pennington,

R.;

Dixon

Wilcox,

H.;

and

Grover,

V.

The

role

of

system

trust

in

business-to-consumer

transactions.

Journal

of

Management

Information

Systems,

(winter

Pine,

B.J.,

III,

and

Gilmore,

J.H.

Welcome

to

the

experience

economy.

Harvard

Business

Review,

Psychometrika,

Steinfield,

C.;

Bouwman,

H.;

and

Adelaar,

T.

The

dynamics

of

click-andmortar

electronic

commerce:

Opportunities

and

management

strategies.

This

study

shows

how

the

TRA

and

TAM

can

be

applied

to

a

new

domain,

thereby

enabling

us

to

see

the

relative

importance

of

many

different

characteristics

in

predicting

reuse

of

a

Web

site.

Its

major

contribution,

however,

is

in

providing

useful

"research

infrastructure"

for

the

domain

of

the

electronic

market

space.

In

the

age

of

the

Internet

and

electronic

commerce,

IS

and

marketing

researchers

and

practitioners

need

a

means

of

assessing

Web

sites.

The

research

effort

described

in

this

paper

has

produced

a

valid

and

reliable

instrument

for

consumer

evaluations

of

Web

sites.

WebQual

can

be

freely

used

by

academics

without

permission.

It

should

be

able

to

support

a

wide

range

of

important

IS

and

marketing

studies

as

researchers

attempt

to

understand

a

variety

of

issues

related

to

the

electronic

market

space.

Although

individual

researchers

may

focus

on

somewhat

different

issues,

and

may

need

to

develop

one

or

more

supplemental

measures

for

their

own

specialized

constructs,

the

existence

of

a

validated

baseline

measure

should

be

a

major

advantage.

It

provides

a

starting

point

that

will

speed

and

enhance

the

quality

of

measurement

for

many

studies.

In

addition,

to

the

extent

that

researchers

converge

on

standard

measures,

it

will

be

much

easier

to

compare

and

consolidate

findings

across

studies..

Of

course,

WebQual

is

not

the

final

word

in

measurement

instruments

for

Web

sites.

Like

any

measurement

instrument

for

an

important

research

domain,

it

will

certainly

be

modified,

added

to,

and

refined

in

various

ways.

There

are

many

frameworks

for

thinking

about

measurement

validity.

The

frameworks

proffered

by

Bagozzi

and

by

Bagozzi

and

Phillips

are

used

in

this

paper

because

of

their

comprehensive

coverage

of

the

six

key

components

of

validity

shown

in

Table

which

are

explained

along

with

the

instrument

development

process

O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O B I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I B I B B I I B I I I B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O 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Preassociative aggregation functions Abstract. The classical property of associativity is very often considered in aggregation function theory and fuzzy logic. In this paper we provide axiomatizations of various classes of preassociative functions, where preassociativity is a generalization of associativity recently introduced by the authors. These axiomatizations are based on existing characterizations of some noteworthy classes of associative operations, such as the class of Aczélian semigroups and the class of t-norms. Let X be an arbitrary nonempty set (e.g., a nontrivial real interval) and let X * = ⋃ n⩾0 X n be the set of all tuples on X, with the convention that X 0 = {ε} (i.e., ε denotes the unique 0-tuple on X). The length x of a tuple x ∈ X * is a nonnegative integer defined in the usual way: we have x = n if and only if x ∈ X n . In particular, we have ε = 0.. In this paper we are interested in n-ary functions F ∶ X n → Y , where n ⩾ 1 is an integer, as well as in variadic functions F ∶ X * → Y , where Y is a nonempty set. A variadic function F ∶ X * → Y is said to be standard [16] if the equality F (x) = F (ε) holds only if x = ε. Finally, a variadic function F ∶ X * → X ∪ {ε} is called a variadic operation on X (or an operation for short), and we say that such an operation is ε-preserving standard (or ε-standard for short) if it is standard and satisfies F (ε) = ε.. For any variadic function F ∶ X * → Y and any integer n ⩾ 0, we denote by F n the n-ary part of F , i.e., the restriction F X n of F to the set X n . The restriction F X * ∖{ε} of F to the tuples of positive lengths is denoted F ♭ and called the nonnullary part of F . Finally, the value F (ε) is called the default value of F .. The classical concept of associativity for binary operations can be easily generalized to variadic operations in the following way. A variadic operation F ∶ X * → X ∪ {ε} is said to be associative [16, 21] (see also [18, p. 24] ) if (1) F (x, y, z) = F (x, F (y), z) , x, y, z ∈ X * .. Here and throughout, for tuples x = (x 1 , . . . , x n ) and y = (y 1 , . . . , y m ) in X * , the notation F (x, y) stands for the function F (x 1 , . . . , x n , y 1 , . . . , y m ), and similarly for more than two tuples. We also assume that F (ε, x) = F (x, ε) = F (x) for every x ∈ X * .. Any associative operation F ∶ X * → X ∪ {ε} clearly satisfies the condition F (ε) = F (F (ε)). From this observation it follows immediately that any associative standard operation F ∶ X * → X ∪ {ε} is necessarily ε-standard. Associative binary operations and associative variadic operations are widely investigated in aggregation function theory, mainly due to the many applications in fuzzy logic (for general background, see [13] ).. Associative ε-standard operations F ∶ X * → X ∪ {ε} are closely related to associative binary operations G∶ X 2 → X, which are defined as the solutions of the functional equation G(G(x, y), z) = G(x, G(y, z)),. x, y, z ∈ X.. In fact, it can be easily seen [21, 22] that a binary operation G∶ X 2 → X is associative if and only if there exists an associative ε-standard operation F ∶ X * → X ∪ {ε} such that G = F 2 . Moreover, as observed in [18, p. 25 ] (see also [5, p. 15] and [13, p. 33] ), any associative ε-standard operation F ∶ X * → X ∪ {ε} is completely determined by its unary and binary parts. Indeed, by associativity we have (2) F n (x 1 , . . . ,. or equivalently,. In this paper we are interested in the following generalization of associativity recently introduced by the authors in [21, 22] (see also [16] ).

O B O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O


QoS Routing in Diffserv MPLS Networks With the emergence of new network applications and quality of service (QoS) Today, the Internet apart from providing web browsing also supports services such as multimedia applications, critical e-business applications, teleconferencing and video conferencing real time services, and Voice over Internet Protocol (VoIP). These applications or services require high-capacity links, and are sensitive to end-to-end delay, jitter and packet loss. As such, the key design of modern Internet should support quality of service (QoS). Effective methods for supporting network QoS are needed. An effort in this direction is QoSbased routing which takes into account the policies and QoS constraints in route computation. The objectives of QoS-based routing (Crawley et al. 1998 ) are as follows:.  Dynamic determination of feasible paths.  Optimization of resource utilization.  Graceful performance degradation during congestion.. Current QoS routing algorithms suffer from some or all of the following disadvantages:.  Higher computational complexity.  Difficulty in to fine tuning the tradeoff between metrics.. In this paper, a polynomial time, dynamic routing algorithm, namely TE-QOSPF-Mix, is proposed. TE-QOSPF-Mix uses enhanced Dijkstra's algorithm (Dijkstra, 1959) in its path computation and provides better trade-off between hop-count and bandwidth optimization.. The paper is organized as follows. Section 2 presents literature survey and related works. Section 3 discusses the proposed mechanism, while Section 4 presents the simulation results and the performance analysis. Finally, Section 5 concludes the paper with future work.

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