ELECTRONIC BULLETIN BOARDS AND     "PUBLIC GOODS" EXPLANATIONS OF COLLABORATIVE MASS MEDIA                         Sheizaf Rafaeli                School of Business Administration                 Hebrew University of Jerusalem                 Mount Scopus, 91905, Jerusalem                             ISRAEL                         Tel. 02-883106                  Online: KBUSR@HUJIVM1.bitnet                               and                        Robert J. LaRose                 Department of Telecommunication                    Michigan State University                  East Lansing, MI  48824-1212                               USA                        Tel. 517-355-4528                           March, 1992Dr. Rafaeli is an Assistant Professor at the School of BusinessAdministration, the Hebrew University of Jerusalem.  Dr. LaRoseis an Associate Professor at the Department of Telecommunication,Michigan State University.  The authors wish to acknowledge theirgratitude for support provided by Michigan State University'sCommunication Technology Laboratory, the Northern TelecomUniversity Interaction Program, and the Rekanati Fund.                   ELECTRONIC BULLETIN BOARDSAND "PUBLIC GOODS" EXPLANATIONS OF COLLABORATIVE MASS MEDIA                            ABSTRACTCollaborative mass media are a new type of mass communicationsmedium in which the audience acts both as the source and thereceiver of the message.  Theories of discretionary data basecontributions and critical mass theory offer parallel, but insome ways distinct, explanations for the success of collaborativemedia. The present research compared the predictions of these twoperspectives in the context of a national survey of publicelectronic bulletin board systems.  The study documented thenature and extent of electronic bulletin board use and comparedseemingly conflicting predictions about the success ofcollaborative media based on the two theoretical perspectives.File contribution levels and system adoption rates were bothfound to be directly related to a measure of symmetry in userparticipation.  Content diversity was directly related tocontribution levels, but not to overall adoption levels.  Theresults provided limited support for discretionary data basetheory.                   ELECTRONIC BULLETIN BOARDS   AND "PUBLIC GOODS" EXPLANATIONS OF COLLABORATIVE MASS MEDIACollaborative mass media systems, in which the audience is alsothe primary source of media content as well as its receiver,represent a new and significant departure from conventional massmedia forms. They expand the very definition of mass media, from"one to many" to "many to many" communication. In the past,audience-generated mass media content has invariably beensubjected to a considerable degree of editorial control and hasgenerally constituted a relatively small percentage of totalmessage system content. Contributions came from a such a smallnumber of audience members that the participants were moreproperly regarded as symbols of the community of interest ratherthan a true embodiment of it. "Letters to the Editor" columns innewspapers and magazines and radio and television call-inprograms are familiar examples.In contrast, new collaborative media mass forms rely almostexclusively upon contributions from a wide cross section ofaudience members, often with minimal editorial control.Electronic bulletin board systems, audiotext "chat lines" andvideotext fora are three examples of emerging interactive masscommunication systems in which the audience is also the source ofthe content. To understand these new media forms, we mustunderstand the factors which prompt audience members to make thecontributions needed to make them viable.Participation in such media is paradoxical, after all.  They areavailable to all members in a community of interest, regardlessof whether the individual consumers contribute themselves, andconsumption of the medium does not diminish what is available toanyone else.  Since no single individual is required tocontribute to the content of the message system in order tobenefit from it, the "rational consumer" might be expected toadopt the strategy of consuming the medium without makingcontributions.  Yet, if no one contributed there would soon be nomedium to consume!  It thus seems that interactivity itselfelicits behavior that transcends the predictions of models of"rational" economic consumption of information (Rafaeli, 1990;Rafaeli and Ritchie, 1991).  More formally, this is the dilemmaof so-called "public goods"  (Barry & Hardin, 1982).How much, why, and when do people contribute to interactive massmedia?  How can we predict, and eventually increase, sharing ofideas, information, intellectual property, and cognitive workamong peers in communities defined by shared communicationenvironments? Two theoretical perspectives have emerged recentlywhich promise to extended our understanding of interactive massmedia forms which rely on the participation of their audiences.Thorn and Connolly (1987, 1990) developed a theory ofdiscretionary data bases from the notion of public goods and usedit to predict rates of contribution to stores of informationshared within an organization.  In a series of laboratoryexperiments, they found that the lower the perceived value of theinformation and the less symmetrical the benefits to users in agroup,  the lower the contribution levels.  Furthermore,individuals contributed less as participation costs and groupsize increased.  However, these results were limited to extremelysmall (four or eight person) groups and took place in alaboratory setting that more closely replicated small workgroupcommunication than a mass media context.Critical Mass theory (Markus, 1987, 1990) takes a parallelapproach, also predicated on the public goods dilemma, whichattempts to explain the growing adoption of interactive media ina community of interest until a state of near totalparticipation, or universal access, comes to exist.  The theorypredicts that the chances of attaining universal access areinversely related to the resource contributions -- in terms ofskill, effort or cost -- required of users.  On the other hand,the greater the heterogeneity of interests and resources foundamong members of a community, the greater the chance of achievinguniversal access. Task interdependence, centralization ofresources, group size and geographic dispersion are hypothesizedto be directly related to heterogeneity and hence to adoption.Critical mass was initially conceptualized with the problem ofadoption of interpersonal communication media -- such as thetelephone and electronic mail -- in mind, but the public goodsargument on which it is based would seem to apply equally well tocollaborative mass media systems.The two theories thus share common underlying assumptions abouthuman behavior in contexts in which collaborative behavior isrequired to create a communications medium.  They both addressthe same general problem of explaining participation ininteractive media that are subject to the dilemma of publicgoods. Both paradigms have matching predictions for one key setof variables relating to the demands placed on the user.  Themore effort, skill, or monetary cost involve, the less theparticipation levels.The two approaches also differ in some important aspects.  Theirindependent and dependent variables, units of analysis and thenature of their predictions are somewhat distinct.Thorn and Connolly's theory of discretionary data bases focuseson individual contribution levels as the dependent variable ofinterest, operationalized in terms of the percentage oftransactions in which subjects choose to contribute information.For Markus, the dependent variable is the collaborative adoptionrate in a community of interest, or the percentage of thecommunity that has adopted the innovation in question.  At apurely operational level, the distinction is simply that criticalmass focuses on the percentage of a community that uses acollaborative medium, while the discretionary data base paradigmexamines the subset of users who also make contributions to thecontent of the medium.  Presumably, there is also a difference inthe time order of the two outcomes.  Initial adoption behavior --including the purchase of necessary hardware and software,obtaining the necessary access codes, logging onto the system forthe first time, etc. -- can be expected to precede contributionbehavior.This distinction may in turn explain the differences inindependent variables.  The value of information and the symmetryof benefits are qualities that can perhaps best be sampled afterinitial access has been obtained through the process of adoption,hence their absence in critical mass theory.   Still, it isreasonable to expect that users form perceptions of thesequalities even before initial adoption, so that they could beexpected to influence the adoption decision as well.Note that the critical mass approach makes the oppositeprediction regarding the role of group size.  If largercommunities are also more heterogeneous, then  critical masstheory predicts that universal access is more likely to beachieved in larger communities.  Indeed, in this viewparticipation is not just directly related to group size, it isexponentially related to the number of participants (cf. Markus,1987).  Thorn and Connolly (1990, p. 227) argue that largesystems reduce the expectation of reciprocity, and consequentlydecrease contribution levels.  Common sense offers a more homelyconstruction:  the more users there are, the more each user cansafely assume that "someone else will do the job."  This couldeven be a positive factor when making an adoption decision.  Whenconsidering whether to adopt a new collaborative medium potentialusers may find larger systems more attractive precisely becausethey seem to require a lesser investment of resources -- in termsof their own contributions -- than smaller systems do.For the purposes of the present research, one possible way toresolve the distinctions between these two public goodsperspectives is to consider them both to be about the factorsthat make collaborative media successful.  The two perspectivesmerely focus on different indicators of success.  One definessuccess in terms of the proportion of a community of interestthat has adopted the innovation, while the other focuses on thecontribution levels of the participants.Other outcome variables come to mind, as well.  Sincecollaborative media also have mass media characteristics, it isnatural to consider conventional mass media outcome measures,such as the amount of usage of the system.  In the case of highlydiverse and volatile media, such as the electronic bulletin boardsystems considered here, system longevity is another appropriateoutcome measure.Electronic Bulletin BoardsElectronic bulletin boards marry the twin interests of mass andinterpersonal communication (Rafaeli, 1986).  The first