Answer garden : a tool for growing organizational memory

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TECHNICAL

REPORT

Answer

Garden

A

Tool

for

Growing

Organizational

Memory

Mark

S.

Ackerman

Thomas W.

Malone

CCSTR#108

SSWP#3144

CENTER

FOR

COORDINATION

SCIENCE

Massachusetts

Institute of

Technology

Sloan School

of

Management

Answer

Garden

A

Tool

for

Growing

Organizational

Memory

Mark

S.

Ackennan

Thomas W.

Malone

M.I.T

"^'^

MAY

1

5

1991

Answer

Garden:

A

Tool

for

Growing

Organizational

Memory

To

be

presented at the

Conference

on

Office

Information

Systems,

April, 1990

Mark

S.

Ackerman^

and Thomas

W.

Malone^

CenterforCoordination Science MassachusettsInstituteofTechnology

Answer

Gardenallows organizationstodevelop databases of

commonly

askedquestionsthat

grow

"organically" as

new

questions arise and are answered. It is designed to help in

situations(such as field service organizations and customer "hot lines") where there isa continuingstream ofquestions,

many

ofwhichoccuroverandover, but

some

ofwhichthe organization has never seenbefore.

The

systemincludesa branching networkof diagnostic questions that helps users find the answers they want. Ifthe answer is not present, the

system automaticallysendsthequestiontotheappropriateexpert,andtheanswerisreturned to the user as well as inserted into the branching network. Experts can also modify this

networkinresponseto users'problems.

Our

initial

Answer Garden

database contains questionsand answersabout

how

tousethe

X

Window

System.

1.

Introduction

Considerthe following

common

problems inorganizations: Customersgetincomplete orinconsistentanswers to theirquestions and complaints.

Employees

get stuck or waste effort

when

theycan't find the specific mformaiion they need. Meanwhile, thepeople

who

couldanswerthesequestionsmay, in

some

cases,beunawareoftheproblemspeopleare having,or, inothercases,they

may

be

overwhelmed

by thesheermassofsimple questions theyhavetoanswer.

The

Answer Garden

system helps an organization solve these problems by providing a database ofanswers to

commonly

asked questions that

grows

"organically" as

new

questionsarise andare answered. Itis designed to help in

situations where there is acontinumg stream of questions,

many

ofwhich occur over and over, but

some

ofwhich the organization hasnever seenbefore.

Such

situations are pervasive in

many

kinds of organizations: field service technicians repairing a company's

products, telephone "hot lines" for customer problems, customer contact personnel (such as airline ticket agents) respondingtocustomercomplaints, teachingassistantshelping studentsinlarge classes,coworkershelping each other with "lore"about

how

touse

complex

computer systems, and even primarycarephysicians treating theirpatients in medical

clinics.

In this paper,

we

willdescribea cooperative

work

txx)l,called the

Answer

Garden, that

we

have designed to help

improve an organization's

"memory"

in situations likethese.

Even

though there is litUeconsensus in the organizational

literature about

how

to define organizational

memory

(e.g., Orr86, Levitt88, Walsh89), the concept of organizational

memory

is an evocative

and

attractive metaphor. Forourpurposes here,

we

will define organizational

memory

as an organization'sability tobenefitfromitspastexperience inresponding

more

effectively(e.g., fasteror

more

accurately) in

the present.

We

will beparticularly concerned with situations where thereisa body of"authoritative"

knowledge

about

how

todo things(such asusingdevices or followingorganizationalprocedures).

ackerman@alhena.mit.edu or ackerman@xv.mit.edu

We

beginbydescribingihekey ideas inthe

Answer

Garden system andihe inceniivespeople

would

have forusing a system like this.

Then

we

present a

more

detailed "tour" ofthe system and descnbe its implementation. Finally,

we

presenta fewobservations from our firstuse ofthesystem(withadatabase of questions and answersabout

how

to usethe

X Window

System),and

we

discussa varietyofissuesthat willarise in large scale use ofsystems like these (such as

how

torepresent conflicting pointsofviewabout aquestion).

2.

Overview

of

the

system

Even

if

someone

in an organization already

knows

the answerto a question, unless that answer can be easily located, otherpeople

may

have torecreate it,overand overagain.

The

Answer Garden

helpsan organization 'improveits

memory"

by captunng answers to questions that

would

otherwise be lostand then providingtools to retrieve theanswers

later. Thereare threekey ideas inthesystem:

(1)

A

branching network ofdiagnostic questions helps users find the answers they want.

The

primary tool to

help users find answers is a branching network of diagnostic questions like those an expert might ask to

diagnose auser's problem (or like thequestionspeople playing the

Twenty

Questions

game

havetoask). For instance, the firstquestion in a database forhardware diagnosis might be

"Does

the

power

light

come

on?

"

withdifferentsubsequent questionsdepending on whethertheanswertothatquestion is"yes" or"no". Atthe

endof each path throughthebranching networkof diagnostic questionsisasetof questionspeoplehaveasked

inthatsituation andtheanswerstothesequestionsprovidedbyexperts.

(2)

New

questions

from

usersareautomatically routedto appropriate experts

and

then inserted(along withtheir

answers)into ihenetwork.

Whenever

users

comes

totheendof a path in thebranchingnetwork anddon't find theanswerto theirquestion(or

when

they have troubleansweringa diagnostic question along theway), they

can enter a

new

question. This question will be sentautomatically toan expert

who

is knowledgeable about questions inthatpartofthenetwork. Then,theexpert'sanswerwillbe returneddirectlytothe user

who

asked

thequestion, and it will also be entered into the network (along with the question) at the point where the questionoriginated. Thus,the

Answer

Garden growsitsinformation databaseovertime.

(3) Expertscan modifythediagnosticbranching networkinresponse to users'problems.

When

expertsconclude from a particular user's question (or from usage statistics for the branching network as a whole) that the

branchingnetwork ismisleading orinefficient forusers, theycanaddto orchange thediagnostic questionsin

the branching network. This

means

that heavily used and well-understood parts of the network will

presumably have well-honed branchingnetworks, while thebranchingnetworks in lightly usedor "frontier" areaswillbe

more

adhoc.

Only

a small

number

ofsimple

components

areneeded technicallyto implementthis system. Yel,sucha system

serves asanexcellent testbcd fora

number

of organizationalandsocialquestions.

3.

Incentives

for

using

the

system

Why

would

peoplewantto use asystem likethis?

As

Grudin (Grudin88) andothershavepointedout, thesuccess ofcooperative

work

systems

may

dependin verysubtle

ways

ontheincentives that differentpeople haveforusing them.

3.1. Incentives for questioners

For

most

questioners, the primary alternatives to using a system like

Answer

Garden would

probably be (a)

finding the answer in

some

otherwnttcn

medium,

or(b)finding a person

who

couldanswerthequestion. In

some

cases, these alternatives

may

be preferable. For in.stance, ifthe questioner

knows

exactly where to find the answer ina printed manual, thatmightbefasterandeasiertolocateandread.

In other cases, questioners

may

prefertoask people they

know,

or people

whose

job it is toanswer questions. Dealing with live people has the advantage thatthe expert can be

more

responsive in helpingto formulate thequestion.

Forinstance, thequestionercan usually justdescribe aproblem inEnglishratherthan havingtoansweraseriesof multiple choicequestions. In

some

cases,dealing with aliveperson

may

simply provide a pleasurablesocial interaction.

Inanimportant

number

ofsituations,however,

we

believetheseadvantages willbe outweighed bytheadvantages of using asystem like

Answer

Garden. With

Answer

Garden, for instance, users can quickly findanswers to previously

asked questionsat any time, even

when

they can't find any

human

experts. Moreover,since the answers in the

Answer

Garden have presumably beenprovidedbyauthoritative experts, userscanusually relyon them

much

more

confidently than

on answers froma

random

colleague

down

thehall.

Even

when

theanswertoa question isnotyetinthedatabase,systemslike

Answer Garden

provide a veryefficient

means

oflocatingappropriate expertssince

new

questions willbe automatically routedtothem.

3.2. Incentives for experts

Forexperts.

Answer

Garden eliminatestheneedtoanswer

many

simplequestions.

The

expertsnolongerhaveto

answerthe

same

questionsoverand over again,and can insteadconcentrateon

more

interestingproblems. For example, oneexpertinourpilotstudy estimatedthat less than

10%

of questionsaskedofhimrequired himtofind

new

information.

3.3. Incentives for organizations

For an organization.

Answer

Garden

provides better, faster, easier to get answers.

Thus

the efficiency, consistency,andqualityoftheanswers givento internalorexternal customersis higher than before. Italso reducesthe

needto havelargeamounts ofexperts' timedevoted torepeatedlyanswering the

same

questions. Finally, as the costsof information technology decline, it

becomes

feasible tocodifyandstore electronically

more

ofthe

knowledge

thatis

now

storedonly informallyinthemindsof people.

4.

A

Tour

of the

Answer Garden

The

userinvokes

Answer Garden

from theprompt lineor a suitable menu. Figure 1

shows

theinitial pane, the control panel. Because the Unix environment in whichthe system operates isa multi-tasking, multi-windowed system, otherprograms(like those

shown

in thebackground of Figure 1)canalsobesimultaneously displayed.

From

thecontrol panel, theusercanchoosebetween the two major

ways

oflocating answers: (1) multiple choice questions,and (2)a U'ee

graph.

4.1.

Helping

users locate

answers

The

primary

way

users locate answers in

Answer Garden

isby answeringa branchingseries of multiple choice questions, startingatthe control panel.

Each

question ispresented inastructuredtextnode(likethose

shown

inFigure2).

When

theuser selectsoneoftheanswers by clickingon theappropriatebutton,thenextstructured textnodeappears, and

theuser continuesanswering multiplechoice branching questionsuntil shefindsthequestion and answerforwhichsheis looking.Therearea

number

of automatic placementoptionsforthenodes.

In

many

cases,

we

expectthis branching networkto beaseries of diagnostic questionslike thosean expert(oran expertsystem)mightask todiagnoseauser'sproblem. It isimportantthatthesequestions be phrasedin a

way

thatusers can understand them. For example, the questions shouldusually referto

symptoms

the usercanobserve(e.g., "Does the

power

light

come

on?"), notlo underlyingcauses orsubtle distinctionsonly an expertcan recognize(e.g., "Doesthe disk

whine soundnormal?").

Some

users,especially experts,

may

already

know

roughly wheretheirquestion is answeredandwill not wantto

"click" their

way down

a long branchingchain to find it. In these cases, userscan selectthe

"View

tree" option in the conu-ol panelandsee atree (like theone

shown

inFigure 3)ofthenodesinthe branching network.

A

usercanthen

jump

immediatelytoany nodein thenetwork.

The

grapherpane

may

includelinkstoothergrapher panes;in thecurrentversion, these are

marked

by usingthe"..." _{conventionloimplyadditional items.}

4.2.

Growing

the

information

database

The scheme

justdescribed workswell

when

the

Answer

Garden knowledgebase containscorrectanswerstoallthe questions people might ask and a well-structured branching network to help people quickly locate the answer to their

question. But what happens

when

the

knowledge

base ofanswers in the system is incomplete or out of date?

What

ifa user doesn'tunderstand aquestion?

What

iftheanswersto

common

questionsare "buried" attheend of a long branching chain?

Answer

Garden

provides two basic tools for dealing with these problems: (1)

new

questions, and (2) usage

feedback.

New

questions are

answered

byexperts.

Whenever

usersare notsatisfied,they can clickon the 'I'm unhappy"

button inany node.

They

mightclick thisbutton, for instance, iftheanswerto their questionisn't presentat a "leaf" node, iftheydon'tunderstandthe branchingquestion theyarebeing asked, orifthey are frustrated withthepath

down

whichthe branchingnetworkistakingthem.

When

usersclick the "I'm unhappy" button, they gettodescribe theirproblemorasktheirquestion directly toa

human

expert

who

is knowledgeable aboutthenodeat

which

the problem occurred. In thecurrent version ofthe system, users

communicate

with the experts via electronic mail; future versions could allow synchronous

communication

with expertsfor

pans

ofthedatabase. Figure4

shows

an

example

ofthe kind ofnode through

which

users can ask their

new

questions.

These

mail messagesare mailed notonly to theappropriate experts but optionally to an additional notification

list.

The

list of experts and notification list can be

changed on

a

node-by-node

basis, allowing organizational customization. Thus,

some

experts

may

be within the boundaries of the group or organization, while others

may

be outsideofit

When

theexpertanswers, theanswerisautomaticallyinsertedintheinformation database.

Expertsuseusage feedbacktorestructure thebranchingnetwork. Therearetwokinds offeedbacktoexpertsabout problems users arehavingwiththe

knowledge

base: (1)

new

questions,and(2)usagestatistics(i.e.,which nodes andpaths are accessed most frequently).

New

questions and their answers are incorporated into the network immediately, thus correctingincomplete orinaccurate things as soon asa userdiscoversthem. Notethat thisensuresthatexperts will spend

their time on questions that are actually useful to people, noton esoteric things that no one ever wants to

know

about.

New

questionscan alsogivefeedback about where the branchingnetworkis ambiguous,confusing, or frustrating.

Usage

statisticsprovide another kind ofindicationabout

how

thesystem isbeingused and where the problemsare. Forinstance,

ifcertain very long branching paths are traveled very often, this is an indication that the branching network should be

revisedtoplacethequestions higherin thetree.

4.3.

Answers

Informationinthe

Answer Garden

canincludesimpletext, structuredtext,pictures,andactiveprocesses.

As

the database grows, mail messages can be included as simple text at first. Later, an expertcan separate

and

structure the information,presenting itinastructuredtextnode.

A

structured textnode caninclude proportionaltext layout,avariety of fonts styles,and active buttons. Active nodes can trigger actions at run-time such asqueryinga remote database, and

thereforebuild

dynamic

information.

Thus

Answer Garden

canserve asthe "front-end" foranentire setofseparate, user-definedprograms.

5.

Implementation

and sample

database

The

currentimplementation for

Answer Garden

is written in

C

for

Unix

(Berkeley

BSD

4.3) platforms. Ituses the

X Window

System extensively. Since

Answer Garden

is tobeavailable as widelyaspossible,all

work

hasbeendone

with the Xt toolkit and the

Athena

widgets, which are publicly available

(McCormack89,

Swick88).

Most

of the functionality isin

new

widgetscompatiblewith theAthenaset.

The Answer

Gardenusesthe standard

BSD

Unixmailandfilesystems.

Answer Garden

nodesarekeptasUnix Oat

nodes

becomes

large,butithas thesharpadvantage ofsimplicity.

Usage

ofthemailsystemis largely invisibleto theend

user;

Answer Garden

invokes the mail system directly. Site-settableand user-settable options(resources) allow

Answer

GardentobetailoredtothevariousUni.x mailhandlers.

We

are testing theinitial

Answer

Garden system usingan information databaseon the

X

Window

System itself.

Since

X

isanewly developed andwidely usedstandard,

many

organizationsdonothavetherange ofexpertiseandsupport necessary forlarge-scaledevelopmentefforts. Based onour discussions with potential users,

we

believethisdatabaseabout

X

willbequite valuabletoa verylarge

number

of peopleat

many

sites.

We

are gathering questions and answers from the most heavily used

X

mailing lists and interviews with staff

members

of the

X

Consortium (the organization that develops and maintains the

X Window

System standards and

software).

We

have askedthe

X

Consortium staff toprovide the most popular questions thatthey answercontinuously,

andtheyhaveagreedtoanswerthe

new

questionsthatareaskedusingthesystem.

As

the

number

of usersgrows andthey ask

new

questions, the

X

databasewillgrow. Thus,

we

are starting witha coreofquestionsandanswers,andexpectingthe userstoexpandour coverage.

We

envisionthesystemashavingthree levelsof information: personal,group, andgeneral.

The

group

may

bea particular site in an inter-organizational system.

Most

of the information will

come

from the

members

of the

X

Consortium, and will be generally true for all

X

users. For example,

X

Consortium staff

may

add nodes about

new

applications thatrunonspecifichardwareplatforms,andallsiteswill getthis information.

Group

orsiteinformation

may

includeinformationtrueonlyata givenlocation,suchas

who

thesiteadministratorsfor

X

are.

6.

Usage

experience

and

issues

Inthefirstphaseofthis study, the

Answer

Garden systemhasbeen usedirregularlyby about8peoplein4 groups

at

MIT

fora period of 4months. In thenextphase ofthestudy

we

will includeseveralgroupsinexternal organizationsas well.

Our

earlyexperience hasakeadyhighlightedseveral issues that

we

expecttobeimportant astheusageandsizeofthe databaseincreases.

Authenticationofinformation.

One

oftheproblemsofbulletin board systemsisthatitisdifficult todetermine

-letalone control- thequalityofthe information.

Answer

Gardenprovides

some

technical

mechanisms

foraccesscontrol, but

much

ofthecontrol will besocial. In thesample

X

database, forexample,only local expertsand

X

Consortium staff

members

can changethe information database.

The

X

Consortium staff

members

are,de facto,theultimateexperts,and

thereforeauthenticationofinformationisnotanissue.

However,

this locking

mechanism

can be bypassed eitherat the

Answer Garden

level or at the

Unix

file level.

Local siteadministrators could,of course,adulterate thedatabase. Moreover,

we

have nocontrolover site-specificnodes; these willbe underthe controloflocalexperts.

We

surmisethataneditingfunction,perhapswithineachsite,

may

become

necessarytocontrolthe qualityoftheinformationandmaintainthedatabase.

A

future

enhancement

almost universally requested is toallow users toannotate the entries.

We

also think it

usefultoallowusers to

fwm

their

own

accesstreesforquickerretrievalof frequentlyusedinformation.

Scaling.

We

expect the

X

information databaseto ultimately

grow

tothousands of nodes.

As

the

number

of

nodes grows,ease of accessforusers will

become more

critical. Currently, only thebranchingquestions andtree graphs

exist; however.

Answer

Garden

has been designed to allow a multiplicity ofretrieval engines. For example,

we

are currently investigatingsemi-structuredretrievalsand

dynamic

trees toprovidegreaterflexibilityacross ranges ofexpertise,

machinecharacteristics,andtechnical interestsofusers.

Inaddition, potentiallythousands ofusers, software engineersandothers, willbe usingthis database. Theseusers are spread across diverse organizationsandgeographicareas,andaccessto a centralizedsiteis notpractical.

Many

ofthe information subtreeswillbeorganizationand sitespecific. For example, the availability andlocation of

X

binary files is

occur continuously,each dayor

more

often.

To

do this willrequire a steady flow of mail traffic to eachsite,bearing the

changestothe informationdatabases.

Representing multiple points ofview. In the scenario

shown

in the figures, an

expen

has arranged the branching questionsin sucha

way

thattheanswersarespecific andsmall. Inothercases,a topic

may

be too recent or general forthe experttodetermine

how

the informauon database should be structured.

Or

there

may

bediffering opmions, even

among

experts, on the correct answer. In thiscase, a "moderator" might help organize thebranching network, but not provide authoritativeanswers.

For example, a user might want to

know

about the advantages ofusing

X

terminalsover workstations. After

answenng

theappropriate questions -_{whether the}problem isa question of

X

usage,of platforms,andofhardware-he can

browsethrough alarge

amount

of mail trafficon the various types of terminals andtheir vendors.

From

time totime, the

moderator might select the

most

interesting messages or modify the branching network to reflect the differences in

icrmmals andvendors.

7.

Related

Work

Answer Garden

has points of

commonality

with a

number

of previous systems. For example, videotextsystems

providea structuredbranchingnetworkto helpusers findinformation.

They

donotusually,however,

aUow

users toeasily ask

new

questionsandhave theanswersautomaticallyaddedintothedatabase via electronic mail.

Electronic mailing lists, computerconferences, and bulletin boards allow ad hoc sharing of information

among

widely distributed groups in response to

new

questions, but they usually provide only the most rudimentary kinds of structure. For instance, it is

common

for

computer

conferences (e.g., HiltzSl) to include a few levels of topics and

subtopics,but

we

arenotawareofany system that treats thisstructure asa diagnosticbranchingnetwork.

At theoppositeextremeofstructure, expertsystems often provide elaborate diagnostic branching networks, but they usually require significant efforttoconstructandthey arenotordinarily thought ofasbeing automatically extensible

inresponseto

new

userquestionsand answersfromexpertsviaelectronic mail.

The

kindsof questionsand answers usedin

Answer Garden

couldcertainly be providedina multi-user hypertext

system (Conklin87,Aksyn87,Trigg88). In fact,one can thinkof

Answer Garden

asan

example

of a multi-user hypertext system.

We

are not aware, however, ofany other hypertext applications that exploit this kindof diagnostic branching networkandareautomatically extensible throughelectronicmail.

Perhaps theclosestprecursors to

Answer Garden

aresystems designed explicitly toaid in providing immediate answers from technical support personnel to questionsabout hardware and software (Coppeto89, Dyson89).

With

the exceptionof

OLC,

thesesystemsappeartobe designedforuse onlybyskilled technical intermediaries, notbytheend users

who

actually have thequestions. Furthermore, thesesystemsdo not appear toincludeadiagnostic branching structure to

helpusers localeanswers.

8.

Conclusion

The Answer Garden

isnot aradically

new

kind of system.

We

believeitshows, however,

how

a relativelysimple

combination of

well-known

concepts can provide a surprisingly powerful platform fora

new

kind of cooperative

work

application.

As

information technology

becomes

more

pervasive,

we

believe that tools like this-for capturing and

exploiting organizational

knowledge

that

was

previously storedonly informally or not at all-will

become

increasingly important.

Acknowedgements

This

work

hasbeen funded inpartbyresearch grantsfrom the

X

Consortium, Digital

Equipment

Corporation,and

the National Science Foundation.

Wc

would

like to thankStuartMadnick,

Bob

Goldberg, Brian Pentland, Ralph Swick,

References

1. Akscyn, Robert;

McCracken,

Donald; and Elise Yoder.

"KMS:

A

Distributed

Hypermedia

System for

Managing

Knowledge

inOrganizations." Proceedingsof Hypertext '87,pp. 1-20.

2 Conklin,Jeff. "Hypenext:

An

IntroductionandSurvey." Cowpurer, September 1987,pp. 17-41.

3. Coppeto,

Thomas

J.; Anderson, Beth L.; Geer, Daniel E., Jr.; and G. Winfield Treese.

"OLC:

An

On-Line

Consulting System for

UNIX."

Proceedings oftheUsenix

Summer

1989 Conference, 1989,pp. 83-94. 4. Dyson,Esther. "Computers,Customers and Hand-Holding." Fc>r/?e5,August 7, 1989,p. 128.

5. Grudin, Jonathan.

"Why

CSCW

Applications Fail: Problems in the Design and Evaluation ofOrganizational Interfaces." _{Proceedings of}theConferenceon Computer-Supported Cooperative Work, 1988,pp.85-93.

6. Hiltz, Starr

Roxanne,

and

Murray

Turoff. "The Evolution of User Behavior in a

Computerized

Conferencing System."

Communications

ofthe

ACM,

November,

1981, pp.739-762.

7. Levitt,Barbara,and

James

G. March. "Organizational Learning."

Annual

Review

ofSociology, 1988,pp.319-40.

8.

McCormack,

Joel; Asente, Paul; and Ralph R. Swick.

X

Toolkit Intrinsics -

C

Language

Interface. Cambridge,

MA:

Massachusetts InstituteofTechnology, 1989.

9. Orr, Julian E. "Narratives at

Work:

Story Telling

As

Cooperative Diagnostic Activity." Proceedings of the

Conference on

Computer

Supported Cooperative Work, 1986,pp.62-72.

10. Swick,RalphR.,and

Mark

S.Ackerman. "The

X

Toolkit:

More

BricksforBuilding UserInterfaces,orWidgetsfor

Hire." Proceedings ofthe Usenix Winter1988Conference, 1988,pp. 221-228.

11. Trigg, Randall H. "Guided Tours and Tabletops: Tools for

Communicating

in a Hypertext Environment." Proceedings oftheConference on Computer-Supported Cooperative Work,1988,pp.216-226.

12. Walsh,

James

P., and Gerardo R. Ungson. "Organizational

Memory:

Structure, Functions, and Applications."

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