Abstract

Several years ago at Bellcore, researchers thought it would be great to access newsgroup contributions by people they admired. They wrote a program to archive and search newsgroups. They tested it by entering the names of a few colleagues. "We soon found," one recounted, "that we were discovering things about our friends that we didn't want to know." The Internet has created a new focus of computation: computer-mediated communication and interaction. Most of what is communicated is received indirectly. On the Web, above all else we see what people produce and make available; also, we read what people say and how others respond, receive indications of what people have done or are doing, and so on. The Internet's greatness resides in this extremely efficient spread of information. It is efficient, but it is not discrete, not tactful. Even when communicating directly on the Internet, we often neglect tact for brusqueness or flaming. Indirect communication and awareness, the focus of this essay, is unsoftened by the technology. A word to the wise Human communication is marked by tact. Knowing when and how to be tactful requires knowledge of the communication context, which is often lost or altered in computer-mediated interaction. Newsgroup messages are written in a context that appears to participants to be "chatting in a room," an ephemeral conversation among a group of like-minded people. But of course what is said can later be read outside that context, by anyone, anytime, anywhere. It can even end up being read in court. Is anything wrong with openness? Is tact necessary? Well, yes, it is. The candor of children, who don't fully understand a conversation's social context, can be refreshing in small doses, but we all learn that tact is essential in most communication. We constantly observe social conventions, avoid social taboos, minimize needless embarrassment, and allow people to preserve the gentle myths that make life more pleasant. Eugene O'Neill's play The Ice Man Cometh outlines a series of calamities that occur when his characters are briefly forced to abandon these myths. Consider another example, in which technology removed an illusion of fairness. A programming class instructor proposed that students submit homework solutions and receive the graded corrections via email. The students produced a counterproposal: After grading an exercise, the instructor posts all of the graded solutions for everyone to see! In this way, the students can discover what had been tried, what worked and what didn't, and which solution is more elegant. They can learn from each other. It sounds great. But, those who have graded papers probably recall that after working through the entire set, you might regrade the first few, because it took a while to work out how many points to subtract for this or that kind of error. Grading is not perfectly consistent. In this class, the grading is visible to everyone. The instructor works harder than usual to be consistent, but stu- IEEE INTELLIGENT SYSTEMS The changing relationship between information technology and society Society and information technology are rapidly co-evolving, and often in surprising ways. In this installment of "Trends and Controversies," we hear three different views on how society and networked information technology are changing one another. Becoming socialized means learning what kinds of behavior are appropriate in a given social situation. The increasing trend of digitizing and storing our social and intellectual interactions opens the door to new ways of gathering and synthesizing information that was previously disconnected. In the first essay, Jonathan Grudin-a leading thinker in the field of computer-supported cooperative work-points out that, like a naive child, information technology often ignores important contextual cues, and tactlessly places people into potentially embarrassing situations. He suggests that as we continue to allow computation into the more personal and sensitive aspects of our lives, we must consider how to make information technology more sophisticated about social expectations. In the second essay, I discuss a related issue-how newly internetworked information technology allows people acting in their own self-interest to indirectly affect the experiences of other people. It is to be expected that people will try to trick or deceive systems that support intrinsically social activities, such as running auctions. What is surprising here is that technologies that do not obviously have a social aspect, such as informationretrieval ranking algorithms, are nevertheless being manipulated in unexpected ways once they "go social." In our third essay, Barry Wellman-a sociologist and an expert in social network theory-explains how the structure of social networks affects the ways we live and work. He introduces the notion of glocalization: the move away from a hierarchical society into a society in which boundaries are more permeable and people are simultaneously members of many loosely knit groups . Wellman describes how computer-mediated communication is contributing to this transition in social habits and infrastructure. As networked information technology continues to provide us with new views of ourselves, we hope that these essay will help designers of information technology better understand the broader impact of the work they do. By Marti A. Hearst University of California, Berkeley hearst@sims.berkeley.edu T R E N D S & C O N T R O V E R S I E S T R E N D S & C O N T R O V E R S I E S JANUARY/FEBRUARY 1999 9 dents still detect inconsistencies, complain, and might conclude that a previously admired instructor is careless or unfair. The instructor works harder than usual to be consistent, but ends up disappointing the students. The students' illusion, their belief in the consistency of grading, is undermined by the technology. It is tempting to welcome a dose of reality, but in these examples, no one is happy about the outcome. Another example: Compliment a conference organizer on the smoothness of the event and you might be told, "If you could see the chaos and near-catastrophe behind the scenes...." Now, technology can reveal what had been "behind the scenes." In the Web's early days, I participated in two conferences in which much of the activity was made visible to all program committee members. For example, once reviews of submissions were written, we could read them online and begin resolving differences of opinion by e-mail, prior to the program committee meeting. Very efficient, but problems arose. Administrative errors in handling the database were immediately seen by everyone and led to confusion or embarrassment. Reviewers could scan the reviews and observe patterns: for example, you were invariably easy, I was invariably harsh; she was a careful reviewer, he was pretty casual about it. In addition, some reviewers felt uneasy about their reviews of a paper being read "out of context" by people who had not read the paper. Assumptions of smooth management and comparable reviewing performance were demolished. The planning of these conferences seemed chaotic to me, but one of the organizers remarked that in his experience, it was in fact unusually smooth, because the organizers knew that all slipups would be visible and thus "we felt we were on stage at all times; we had to be careful." Our difference in perception arose because the technology made visible more of the underlying reality. The underlying reality What is the underlying reality? Ethnographers or anthropologists have studied workplaces and repeatedly shown that behavior is far less routine than people believe. Exception-handling, corner-cutting, and problem-solving are rampant, but are smoothed over in our reports and even in our memories, whether out of tact or simply to get on with the job. People normally maintain an illusion of relative orderliness. Technology is changing that. The more accurately and widely it disperses information about the activities of others, the more efficiently we can work, but at a price: irregularity, inconsistency, and rule breaking that were always present are now exposed and more difficult to ignore. In a well-known example, technology could detect all automobile speeding violations. If we don't use it, how do we decide when and against whom to selectively enforce the law? A police officer might use context to guide enforcement-weather and traffic conditions, perhaps. We might tactfully overlook a colleague's occasional tardiness. But technology is poor at assessing context; it does not tactfully alter a time stamp. We once could imagine a colleague as an imposing person, who pays attention to detail, but e-mail reveals his careless spelling, his outdated Web site instantly reveals a relative lack of organization or concern for his image, and a video portal catches him picking his nose. None of this negates the huge benefits of these technologies, but it creates a challenge. Many challenges, in fact: in our computer-mediated interactions during the days and years to come, we will have to address this issue over and over, as individuals, as members of teams and organizations, and as members of society. What to do? How can we address technology's lack of tact, its inability to leave harmless illusions untouched? Can we build more tact into our systems? Spelling correctors help. Perhaps the video portal, detecting a colleague changing clothes for a tennis match and having forgotten about the camera, could recognize what is happening and discretely blur the focus. Perhaps a virtual Miss Manners could proofread my e-mail, or a virtual lawyer could scan an automatically archived meeting and flag sensitive words. But realistically, these are exceedingly subtle, complex, human matters involving knowledge of an interaction's context, tacit awareness of social conventions and taboos, and appreciation of which illusions and corner cutting are harmless or even beneficial and which are problematic. It is a worthy goal, but intelligent systems will only slowly start to carry some of the weight. Another possibility is to retreat. In some cases, we will decide the increased efficiency isn't worth it. In the examples I've cited, the newsgroup scanner was abandoned, the conferences stopped making as much information visible in subsequent years, and posting graded exercises has not become a custom. But these were intentionally extreme examples. Examples abound in the daily use of the Internet and Web, from which there will be no retreat. Our actions are becoming much more visible; the global village is arriving. And, in general, I believe there are tremendous benefits in efficiency, in the fairness that visibility promotes, and in the ability to detect significant problems and inconsistencies. We might be too worried, too cautious in embracing these new technologies. A third approach seems inevitable: We will find new ways to work, to organize ourselves, and to understand ourselves. The solutions might not be obvious. I have frequently described the case of the programming class instructor, who works harder but has a more dissatisfied class, as an apparently insoluble dilemma. I recently presented it to Douglas Engelbart. He thought for several seconds, then said, "The class could develop a collective approach to grading assignments." Coming Next Issue Intelligent Rooms When information technology "goes social" Marti Hearst, UC Berkeley In everyday life we often observe the unintended consequences of the actions of individuals on society as a whole. If I intend to go to San Francisco from Marin County, I might well get in my car and drive to the Golden Gate Bridge. Although I certainly do not have the goal of slowing down someone else's trip to the city, my action might indeed contribute to this result. I can even unintentionally add hours to the travel time of thousands of fellow motorists if my car stalls on the bridge. Most people do not ever consider deliberately blocking traffic, but there are exceptions. Protestors can exploit the vulnerability of the freeway system to tie up the rush-hour commute, and youths can deliberately disrupt local traffic patterns by "cruising" suburban streets. The rise of the Web and other networked information technologies has brought about new, sometimes surprising, ways for the actions of individuals and small groups to have impact on other people with whom they otherwise have no relationship. Many of these new opportunities are exciting and promise great benefits. For example, after I purchase a book from Amazon.com, I am shown suggestions of books bought by other people who also bought my new book. If I want to find out how to fix an electrical problem with my car, it may be the case that someone I never met has written up a solution and placed it on the Web. However, the interconnectivity and global accessibility of the Web has also given rise to some unexpected ways in which people can take advantage of the technology at the expense of other people. Applications that heretofore would not have been assumed to have social ramifications are in fact allowing unexpected interactions among their users. This essay presents the case that information scientists need to begin thinking about design in a new way-one that incorporates the potential consequences if the output of their systems are likely to "go social." Information technology "goes social" when the exposure of its output makes a transition from individuals or small groups to large numbers of interconnected users. Gaming Web search engines Let's look at a few examples. The first is a field I know well-information retrieval. The standard problem in IR is that of helping users find documents that (partially) fulfill an information need. If there were only a few documents to choose from, finding the relevant ones would be a simple process of elimination. However, there are millions of valuable documents as well as myriad documents of questionable general worth (for those who think the Web contains mainly junk, the Library of Congress alone catalogs over 17 million books, and a trend toward moving materials online will ensure large amounts of high-quality online material). Given many equally valid pieces of information coexisting simultaneously, the problem becomes that of pushing aside those that are not relevant, or pulling out the few that are relevant to the current need. Thus it is not so much a problem of finding a needle in a haystack, as finding a needle in a "needlestack." IR is different than retrieval from a standard database-management system. In DBMSs, all information is entered in a precisely controlled format, and for a given query there is one and only one correct answer. By contrast, IR systems must make do with only an approximation to an accurate query, ranking documents according to an estimate of relevance. This fuzzy behavior is an unfortunate consequence of the fact that automated understanding of natural language is still a distant dream. Instead of understanding the text, an IR algorithm takes as input a representation of the user's information need, usually expressed as words, and matches this representation against the words in the document collection. In practice, if the query contains a relatively large number of words (say, a paragraph's worth), then documents that also contain a large proportion of the query words will tend to be relevant to the query. This works because there tends to be overlap in the words used to express similar concepts. For example, the sentence "The Mars probe Pathfinder is NASA's main planetary explorer" will tend to share words with a newspaper account of the same topic. However, this strategy is not infallible; if an inappropriate subset of query words overlaps, nonrelevant documents may be retrieved. For example, an article containing the sentence "A vandal easily mars the paint job of the Pathfinder, the Explorer, and the Probe" shares four terms with the previous sentence, although their meanings are quite different. Additionally, the short length (1-2 words) of queries submitted to search engines could cause IR systems to retrieve documents unrelated to the user's information need. For example, a user searching for articles on Theodore Roosevelt might find information about a football team located at a school named after this US president. Thus IR systems circumvent the need for automated text understanding by capitalizing on the fact that the representation of a document's contents can be matched against the representation of the query's contents, yielding inexact but somewhat usable results. For over 30 years, IR research has focused on refining algorithms of this type. However, in the course of those 30 years, no one had the faintest glimmer of what would happen when IR technology went social. What had never been imagined was that authors would deliberately doctor the content of their documents to deceive the ranking algorithms. Yet this is just what happened once the Web became widespread enough to be attractive to competing businesses, and once search engines began reporting that thousands of documents could be found in response to queries. Web-page authors began gaming the search-engine algorithms using a variety of methods. One technique is to embed the contents of the wordlist of an entire dictionary in the Web page of interest. (The words are hidden using the HTML comment tagcomments are invisible to humans reading the page, but are indexed by some Web search engines. A similar effect can be achieved by formatting the text in the same color as the page background.) For the reasons I've described, the inclusion of additional words, whether or not they have anything to do with the content of the page, increases the likelihood of a match between There are also cases of authors placing words that are known to be of interest to many information seekers ("sex" or "bugfree code," for example) into a Web page's meta tag field, because some search engines assign high weight to meta tag content. A variation on this theme is to use a word that really is relevant to the content of the Web page, but repeat the word hundreds of times, exploiting the fact that some search engines increase a document's ranking if a query term occurs frequently within that document. Listing the names of one's competitors in the Web page's comments section can also mislead a search engine; if a user searches on a competitor's name, the search engine will retrieve one's own Web page but no information about the competitor will be visible. These techniques could be seen as modern-day equivalents of naming businesses in such a manner as to get them listed first in the phone book-AAA Dry Cleaners, for example. This doctoring of the content of documents might also be considered an entirely new way of using words as weapons; a new way to make words mean other than what they say; something we might call subliminal authoring. Search-engine administrators quickly catch on to these techniques. Ranking algorithms can be adjusted to ignore long lists of repeated words, and some search engines do not index comments or meta tags because of the potential for abuse. This can quickly devolve into a series of moves and counter-moves. For example, users can submit Web-page URLs to search engines to get the pages reindexed and thus have the index reflect changes more rapidly. Some Web-page doctorers (incorrrectly) assumed that multiple submissions of a page would cause its ranking to increase, and so tried submitting their pages thousands of times over. Search-engine administrators noticed this behavior and started taking punitive action against repeat resubmitters. In response, some people have considered repetitively resubmitting the Web pages of their competitors in the hopes of getting these pages eliminated from the search engine indexes. 1 Of course, search-engine providers aren't all innocent in this. It is claimed that some will rank Web pages higher than others for a fee. This kind of behavior is also something that simply would not have been thought of in the earlier, pre-social days of information retrieval. System design for social interactions The lower levels of networking software allow computers to send and receive data from one another. The difficulties with such software reside in the design of systems that work accurately, reliably, and efficiently. However, it has become apparent that the difficulties in the design of systems that support interaction among groups of people or on behalf of people lie not so much in the creation of efficient, reliable algorithms. Instead, these systems must be designed to take into account fuzzier concerns relating to the social practices, assumptions, and behaviors of people. Computer-supported cooperative work (CSCW) researchers have shown that groupware applications such as shared calendars and meeting tools must be sensitive to the various conflicting goals of the group participants. For example, administrative assistants, engineers, and managers disagree on what the important features of a calendar/scheduling system are. 2 Information systems that take actions on behalf of human users must take into account how users might try to manipulate the system. Designers of auction or voting systems must consider how users might try to deceive the system by voting multiple times or preventing others from voting. Designers of agents that negotiate prices for goods must consider the potential for bait-andswitch pricing tactics, pricing collusion between competitors, and general fraudulent business practices. Because these systems perform actions traditionally done by people interacting with one another, it is perhaps unsurprising (in retrospect) that social considerations must be taken into account to make these systems succeed. The new phenomenon we observe here is that even systems whose underlying goal is not that of supporting social interactions are nevertheless being used in this manner. We might need to accede that when information technology goes social, information-system developers must learn to adopt defensive strategies, just as neophyte drivers have to learn about defensive driving. Defensive driving is not necessary if there are no other drivers on the road; similarly we do not need this type of defensive strategy with information technologies unless they are networked together. What's in a domain name? Let's now consider another example. A Web-page server's "real" network address is a represented as a string of digits separated by periods. These serve as identifiers to allow computers on the network to distinguish one from another. However, Web servers also support URLs that contain domain names, which act as mnemonic pseudonyms for the numeric IDs. Usually, a domain name reflects the name of the institution to which it belongs. For example, www.berkeley.edu refers to the UC Berkeley home page, and www.whitehouse.gov refers to the US White House's home page. An entirely unexpected and opportunistic exploitation of these naming conventions has arisen, relying on the fact that people tend to make spelling errors. Web sites have been created whose domain names have no resemblance to the content they contain, or whose domain names are common misspellings of the names of popular sites. For example, www.whitehouse.com contains pornographic material; conversely, www. playby.com consists solely of advertisements for technical products. Names are not particularly important when a computer is communicating with another computer. Within computer systems, ID strings serve simply to distinguish one entity from another and do not have intrinsic meaning. However, once exposed to and used by people, the symbols take on meaning. People will interpret and interact with the identifiers in ways impossible to imagine a computer doing. Most likely the creation of mendacious domain names would not have been thought of, much less considered important, until large numbers of people became interconnected, using not only the same technology but also viewing the same information. This situation stems in part from the rather egalitarian manner in which domain names were originally assigned. In fact, domain names were allocated in a manner similar to how the Department of Motor Vehicles assigns vanity license plate names. Pretty much anyone can have pretty much any license plate as long as it isn't already taken by someone else and fits within the prescribed length limitations and uses the standard alphanumeric characters. Licenseplane names are also subject to certain restrictions about what constitutes good taste, and it has long been a game of the public versus the DMV to try to fool the censors into accepting license plates with questionable interpretations. The difference between URLs and license plates, of course, is that only a few people can see a license plate at any one time, and they are not particularly useful for business on a large scale. Also, a car cannot be instantly retrieved just by invoking the name on it's license plate. Hypertext I am a member of an interdisciplinary program whose faculty include computer scientists, law professors, economists, and other social scientists, and whose mission is to integrate the social and the technical in the study of the organization, management, and use of information. One day in lecture last semester, I mentioned to our interdisciplinary masters students that HTML and the Web ignored much of what had been learned about hypertext in the preceding decade, including such things as link types and bidirectional links. One student asked what would happen if the Web allowed bidirectional links. I did what all smart professors do when posed with a difficult question in class: instead of answering, I made it into a homework assignment question. I asked the students to perform a gedanken experiment, and discuss what would happen if the Web supported bidirectional links. They were to consider a scenario in which, if a link was made from A to B on any page, a reverse link could be forced to appear from B to A. In my computer scientist naivete, I assumed this would be a good thing, allowing me to easily show citations at the end my text and have the citations point back to the place in the text from which they were referenced, make it easier to make tables of contents, and generally make it easier to find related information. However, the socially savvy students' answers surprised me. Out of 19 students, only one thought bidirectional links would be an inherently good thing. Instead, they foresaw all manner of disastrous outcomes, including • Link spamming: for example, people could damage a company by flooding its home page with spurious backlinks, or people could force someone's personal home page to link back to an offensive page about themselves (such as "babes of the Web"). • False endorsements: people could make it look as if some entity endorsed their Web page by linking to that entity; pages could be forced to link to advertisers' pages. • Loss of control of information: If bidirectional links were the only type of link available, their use could prevent the ability to hide internal information, as in the case in which a link internal to a firewall pointed to a page in the external world. Of course, no one has suggested implementing forced bidirectional links in this way (the standard technical solution is to store all links in a separate link database, rather than place them within the page itself). On the Web, standard read/write restrictions on file systems prevent this kind of activity. However, when discussing why bidirectional links were not used in the design of HTML and HTTP, these kinds of concerns are not named. In the design notes for the WWW, Tim Berners-Lee writes: Should the links be monodirectional or bidirectional? If they are bidirectional, a link always exists in the reverse direction. A disadvantage of this being enforced is that it might constrain the author of a hypertext-he might want to constrain the reader. However, an advantage is that often, when a link is made between two nodes, it is made in one direction in the mind of its author, but another reader may be more interested in the reverse link. Put another way, bidirectional linking allows the system to deduce the inverse relationship, that if A includes B, for example, that B is part of A. This effectively adds information for free. ... 3 Here, Berners-Lee expresses concern about a lack of control by the author over the reader's experience, but none of the potentially negative social impacts considered by my students comes into account. Before going social via the Web, most hypertext linking happened within a single document, project, or small user group. In IEEE INTELLIGENT SYSTEMS What had never been imagined was that authors would deliberately doctor the contents of their documents to deceive search-ranking algorithms. JANUARY/FEBRUARY 1999 13 the late 80's, before the rise of the Web, there were many competing technologies, none compatible with the others Since going social, hypertext has become useful for linking information in far-flung places, assembled by people who don't know each other or have access to one another's data. Links outside of given projects can be more useful than internal ones, because they lead to resources less likely to be known to the internal group members. However, this kind of interaction was not on the radar screen in hypertext thought and research. For example, in the ACM Hypertext 89 proceedings, 4 the authors were generally concerned with semantics of link types, navigation paths, how not to get lost (still a big problem!), and how to author hypermedia documents. Only two papers discuss the possibility of cross-project links. The first, a systems paper by Amy Pearl describing how documents on different systems might be interlinked, simply assumed bidirectional links as the only link type. The other paper, called "Design Issues for Multi-Document Hypertexts" by Bob Glushko, shows clearly that at the time the notion of inter-document linking in real systems was a radical one. In his closing plenary address at Hypertext 91, 5 Frank Halasz revisited the issues he had raised in his landmark 1987 paper "Reflection on NoteCards: Seven Issues for the Next Generation of Hypermedia Systems." These issues related to searching, link structure, and various computational concerns. Halasz also discussed supporting social interactions over a hypermedia network, but focused on Randy Trigg and Lucy Suchman's notion of mutual intelligibility 6 (making sure participants can understand what each person is doing) and how to write readable hypertext (which in retrospect he realized did not belong in the social category). Halasz also introduced four new issues, one of which was the need for open systems to allow cross-system linking, and another which he called the problem of very large hypertexts. The problems he foresaw in this category had to do with scaling large systems and disorientation in large information spaces. He did not mention potential social concerns. A Ted Nelson, who coined the term "hypertext" in 1965 and who since then has been an evangelist for its execution in his vision of the Xanadu system, did worry about certain social issues, namely copyright and how to handle payments for access (this system was the subject of a critical legal analysis by Pamela Samuelson and Robert Glushko, which brought up additional social issues 8 ). In the Xanadu system, authors were to pay to put their writings in the system, and readers were to pay to read these works. Readers could also add hyperlinks to improve the findability of information within the system, and would receive payment when other readers used these links. Link creators would only be compensated if their links were traversed by others, thus motivating authors to create high-quality links. However, pernicious links like those anticipated by the SIMS students were not considered, perhaps because Xanadu was to be a closed system over which its administrators could exert control. 8 A true exception can be found in Jakob Nielsen 's 1990 book Hypertext & Hypermedia. 9 On page 197 of this book of 201 pages, under the heading "Long Term Future: Ten to Twenty Years," he cautiously predicts large shared information spaces at universities and some companies. In this context, he points out some potential social consequences of shared information spaces. If thousands, or even millions of people add information to a hypertext, then it is likely that some of the links will be "perverted" and not be useful for other readers. As a simple example, think of somebody who has inserted a link from every occurrence of the term "Federal Reserve Bank" to a picture of Uncle Scrooge's money bin. ... These perverted links might have been inserted simply as jokes or by actual vandals. In any case, the "structure" of the resulting hypertext would end up being what Jef Raskin has compared to the New York City subway cars painted over by graffiti in multiple uncoordinated layers. 10 Interestingly, three paragraphs later, he also proposes the use of popularity of following hyperlinks as a measure of the usefulness of the link, but does not consider the possible gaming effects using this technology, as I discuss next. Collaborative ratings Information technology going social can open up new opportunities. Many researchers and developers have noted that information technology allows for the tracking and logging of the information seeking behavior of masses of users. One oft-stated suggestion is to gather information about preferences by users' implicit choices, by keeping track of which hyperlinks are followed, which documents are read, and how long users spend reading documents. It is hypothesized that this information can be use to assess the popularity, importance, and quality of the information being accesses, and used to improve Web-site structure and search-engine ranking algorithms. Again, unanticipated behavior might undermine the integrity of these systems. If the results of these algorithms lead to commercially important consequences, such as changing a site's ranking within search results, then people will be likely to write programs to simulate users' visiting the Web pages of interest, and countermeasures will be required. Researchers are also making use of explicit rating information, most notably in what is known as collaborative-filtering systems or recommender systems. 11 Collaborative-filtering systems are based on the commonsense notion that people value the recommendations of people whose recommendations they have agreed with in the past. When new users register with a collaborative-filtering system, they are asked to assign ratings to a set of items (such as movies, recipes, or jokes). Their opinions are then matched against those of others using the system, and similar users are identified. After this, the system can recommend additional items to the new users, based on those that have already been rated by similar uses. Collaborative filtering is a social phenomenon. Researchers have discussed some of the social dilemmas that can work to the detriment of such systems, especially issues having to do with motivating people to be initial reviewers rather than waiting for others to create the ratings. 11 However, as we've seen, there are less obvious kinds of interactions that can degrade the system's behavior, which arise only because large masses of people use the same system. In a recent manuscript, Brent Chun points out the motivations people might have for deceiving the system and some ways in which they might carry out this deceit. 12 He proposes that companies whose services are being rated might attempt to affect the ratings they receive or downgrade the ratings of their competitors, specific interest groups might try to further their causes by giving negative ratings to companies or products that conflict with their beliefs, and collaborativefiltering companies themselves might try to sabotage the ratings of their competitors. Chun suggests ways people might attack the ratings databases, including conventional security threats such as breaking into the system to steal or modify the database. He goes on to discuss more ingenious means for defrauding these systems, such as rating the same item multiple times using large numbers of pseudonym identities, borrowing other users' identities, and collusion within groups of authentic users to downgrade an item's rating.