Symmetry was the percentage of board users characterized by theboard operator as being either "givers" ("who share knowledge andresources") or "exchangers" ("participating in a fair exchange"),as opposed to "Takers" ("who are looking for 'something fornothing'")Additional questions about the characteristics of boards, theiractivity levels and management practices were also included inthe survey.  Open ended-questions about purpose ("How do youdefine the purpose of your board?"), scope ("How do you describeyour target community?") and success factors ("What do YOU thinkmakes a bulletin board system successful?") were included tofurther discern the nature of bulletin board activity.                             RESULTSUsable responses were received from 126 boards located in forty-five different states.  Some of the boards were quite long-lived,including one that was eleven years old at the time of thesurvey, and twenty-five percent of those surveyed were over fiveyears old. Thirteen percent had been in existence for only a yearor less. The average longevity was about three and a half years(41.6 months).  On average, thirty-eight percent of the weeklyfile transactions involved the contribution of files from users.An average of eighteen percent of the boards' user universe(defined as the number of different callers) are active users,placing calls on a weekly basis.  Slightly over fifty calls perweek are made to the typical board in the survey, but the rangeis quite wide.  One of the boards reported 2000 weekly calls.The average user community served included nearly 900 (886.9)different users.  The boards surveyed were very diverse in termsof the nature and scope of their target audiences.  The boardsincluded in the sample ranged from general purpose systems available to allcomputer users (39%) to highly specializedsystems dedicated to specific groups.  Twenty percent of thesystem operators said that their boards were either national orinternational in scope.  The specific audiences cited includedcomputer professionals, handicappers, children, lawyers, hamradio operators, AIDS professionals and victims, physicsresearchers. Sixteen percent of the boards identified upper class(i.e., high income or highly educated) individuals as theirtarget audience.Bulletin board systems are defined as much by the nature of theircontent as by the characteristics of their audiences.  Some ofthe more highly specialized systems in the sample included publicboards operated by large corporations and service organizationsand product support bulletin boards for software companies.  Ofcourse, all board users share an interest in computing, since apersonal computer or terminal is required for access.  Onaverage, about two-thirds of board content is devoted tocomputer-related matters, but only nine percent of the boardswere exclusively computer related.  In contrast, twenty-twopercent of the boards said that half or more of board content wasunrelated to computer topics.Abuse is an important issue for board operators.  Common abusesinclude evasion of rules against excessive downloading andlengthy sessions that tie up incoming lines, the uploading of"junk" files and the placement of obscene or abusive messages onthe boards. Over two-thirds of the boards in the sample reportedinstances of abusers.  The most common policy for dealing withsuch abuse was the termination of access rights.  Fewer operatorsreduced access rights, and only about half limited downloading.The least popular strategy was notification of the police,reported by one in seven operators.A wide variety of board management policies are in effect toforestall such problems.  Twenty-three percent of the boards saidthey charged either recurring or per transaction fees to users.Forty-one percent enforce some form of download ratio in anattempt to curb "selfish" users who merely take files withoutoffering up files of their own.  Time limits were in effect forall but six percent of the boards.  The average maximum length ofcall allowed was about an hour (55.6 minutes).  The longest timelimit was two hours.  In fact, 44 percent of all boards surveyedhad a time limit set at exactly 60 minutes.  Furthermore, mostboard operators award access time by user status.  Less than halfcredit additional time based on upload history, and about a thirdallow users to purchase access time.  Other access policiesincluded preferential treatment for visiting operators from othersystems, time of day differentials, and the award of more timeupon request.Another mark of successful board management is the ability todevelop active participation.  When asked to classify their usersas "Givers", "Exchangers", or "Takers", system operatorsclassified more of their users as "Takers", than either of theother two categories.  The median percentage assigned to "Takers"was 50 percent, while the median for each of the other, 'lessselfish' categories was 20 percent.The "art" of running a bulletin board is still being defined.When asked to describe factors in the success of bulletin boardsystems, the most frequently cited factor was the responsivenessof the system operator to user needs, which was mentioned bytwenty-three percent of the respondents.  The quantity of filesavailable and the quantity of user contributions were each citedby nineteen percent of the respondents.Table 1 displays means, standard deviations and correlationcoefficients for the dependent and independent variables used totest the hypotheses for the present study.  The dependentmeasures of system success were generally not very highlycorrelated. The only significant correlation among the measuresof system success was a negative correlation between contributionlevels and system longevity (Pearson r=-.21, p < .05).Accordingly, the patterns of relationships with the independentvariables were considered separately for each of the indicatorsof system success.Contribution levels were not significantly related to thepresence of upload-download ratio restrictions, timerestrictions, or the imposition of user fees.  The relationshipsto transaction ratios, time restrictions and fee policies were inthe directions hypothesized, even though they were notsignificant.  Content diversity was directly related tocontribution levels, as hypothesized (r=.27, p < .01), as wassymmetry in contribution levels (r=.22, p < .05).  Group size wasnot significantly related to contribution levels, although againthe relationship was at least in the direction expected.Adoption levels, defined in terms of the proportion of regularusers among the total community of users, were negatively relatedto group size (r=-.33, p < .01), the opposite direction of whatwas predicted from critical mass theory.  Symmetry incontribution activity was positively related to adoption levels(r=.30, p < .01), as expected.  The other hypotheses were notsupported and the directionalities of the relationships observedwere generally opposite those predicted.  The exception was thatleniency in access time restrictions was positively related toadoption levels, which was the direction hypothesized.The longevity of the boards surveyed was positively related togroup size, as predicted (r=.40, p < .01), but the otherhypothesized relationships were not supported.  Only theprediction about content diversity was in the anticipateddirection.Finally, weekly usage levels were directly related to group sizeas hypothesized (r=.27, p < .01), but were positively correlatedto the existence of a fee policy (r=.19, p < .01), contrary toexpectation.  The other relationships were not only notsignificant, but tended to be in the opposite of their predicteddirections.                           DISCUSSIONThe exchange of files and messages occurring on electronicbulletin board systems has a mass communication flavor to it.  Ithas been occurring on a fairly large scale for well over adecade.  Unlike traditional mass media vehicles which involveone-to-many dissemination of content, bulletin boards arecollaborative efforts defined by a many-to-many relationship.The members of the community of interest participate in thecreation of the message. Such participation is of both practicaland theoretical import.It appears that structural characteristics of collaborative massmedia systems seem to be more critical to their success thanspecific management policies applied by system operators.  Thediversity of content and the symmetry of exchange between participants werethe most important of the factors derived frompublic goods theories which predict bulletin board systemsuccess. The day-to-day operating restrictions placed on users --including upload ratios, access time restrictions and user fees-- generally had little relationship to measures of boardsuccess.The above statement must be heavily qualified according to whichmeasure of success is in question.  The predictions of publicgoods theory best explained contribution levels, but did not seemto be a "good fit" for the other outcome measures of adoption,longevity and usage.  The results were not very robust even forcontribution levels.  Perhaps there are distinct processes whichuniquely explain these different aspects of collaborative massmedia systems, apart from public goods explanations.It seems that the predictions of public goods theories needfurther refinement when applied to collaborative mass media.  Insomewhat of a challenge to Public Goods theory, and mild supportof Critical Mass theory, symmetry in user contribution behaviorwas related positively to both contribution and adoption rates.It may be that the open-ended nature of public collaborativemedia makes them a different case from collaborative media thatexist in closed group settings, such as in organizations.  When apublic board is the beneficiary of exceptional contributions fromusers, there is a ready supply of new users who will be attractedand offset any problems with the "over-supply" of information.The present results perhaps indicate a need to re-assess theimportance of symmetry in contributions from user groups in openmedia systems.The picture emerging from these data is of a more complex worldthan predicted by either theory.  There were small-scale,rationally managed, tightly economical (or exchange-governed)boards, where the public goods of information were traded.  Atthe same time, many other boards exist and survive, where theemphasis is on diversity, numerous callers, and generalizedreciprocity expectations rather than tightly managed quantitativeexchange rates.In future research it would be worthwhile to re-conceptualize andtest some other system management issues in public goods terms.In the present sample of system operators, their ownresponsiveness, the quantity of files available and the quantityof user contributions were deemed the most important factors insuccess.The operator, as "the master user," has the ability to controlthe symmetry of the exchange through her own contributions to theboard.  This might be especially true of smaller boards, in whichan active system operator could affect the gross exchange rate inmeaningful ways.  In such cases, the expertise of the operatorand the centralization of resources represented by that personcould create the "heterogeneity of resources" which critical masstheory holds is an important driver of universal access.The quantity of files available also has meaning in public goodstheories.  The larger the file library, the more likely that"heterogeneity of interests" may be obtained, in critical massterms, driving user adoption.  Thorn and Connolly's theory ofdiscretionary data base contributions would seem to make theopposite prediction with respect to contribution levels:  Facedwith a wide array of valuable files, individual users might bediscouraged from making contributions of their own.  The chancesof inducing others to contribute by offering files that only makea marginal addition to an already expansive data base would seem to be slight,so contribution behavior should be inhibited by thesheer volume of files available.While on the topic of system content, this seems to be anotherarea worthy of further consideration by public goods theorists.In the current research, the diversity of content was related tocontribution levels, although not to adoption rates.  There isroom for much refinement of the content diversity variable, suchas defining it in relation to the number of different topicscarried and the number of files devoted to each.  The quality ofthe content should also be an important factor, although it isdifficult to imagine a satisfactory measure of quality that couldbe assessed at the system level.The final "success factor" identified by the system operators --