Chrysanthos Dellarocas

Boston University | BU · Department of Information Systems

We propose an approach for uncovering characteristic response paths of a population from an individual-level multivariate time series data set. The approach is based on a model that accommodates a set of arbitrary distributions for endogenous variables and interstep intervals and variables. The model enables reliable estimation of individual-level...

Social media have great potential to support diverse information sharing, but there is widespread concern that platforms like Twitter do not result in communication between those who hold contradictory viewpoints. Because users can choose whom to follow, prior research suggests that social media users exist in 'echo chambers' or become polarized. W...

Although many researchers in information systems and marketing have studied the effect of product reviews on sales, few have looked at their effect on product returns. We hypothesize that, by reducing product uncertainty, product reviews affect the probability of product returns. We elaborate this hypothesis starting with an analytical model that e...

In this paper, we study the question and answer (Q&A) feature of electronic commerce platforms, an increasingly common form of user-generated content (UGC) that allows consumers to publicly ask product-specific questions and receive responses, either from the platform or from other customers. Using data from a major online retailer, we show that Q&...

News aggregators have emerged as an important component of digital content ecosystems, attracting traffic by hosting curated collections of links to third-party content, but also inciting conflict with content producers. Aggregators provide titles and short summaries (snippets) of articles they link to. Content producers claim that their presence d...

Social media have great potential to support diverse information sharing, but there is widespread concern that platforms like Twitter do not result in communication between those who hold contradictory viewpoints. Because users can choose whom to follow, prior research suggests that social media users exist in "echo chambers" or become polarized. W...

A digital consumer’s purchase journey, referred to as the path to purchase, is non-linear and heterogeneous. Despite a strong interest in this concept, there are few published approaches to empirically extract consumers’ path to purchase (in terms of a sequence of different types of activities leading to purchase), especially in settings where cons...

Motivated by the growing practice of using social network data in credit scoring, this study analyzes the impact of using network based measures on customer score accuracy and on tie formation among customers. We develop a series of models to compare the accuracy of customer scores obtained with and without network data. We also investigate how the...

This paper delineates the main characteristics of the evolution of the organization as a social business in response to the socially networked marketplace. We advance the notion that the modern day firm is increasingly organized as a community according to the principle of collaboration. The main message is that the prominence of organizational str...

Considering new business models for massive open online courses.

Social media are fundamentally changing the way we communicate, collaborate, consume, and create. They represent one of the most transformative impacts of information technology on business, both within and outside firm boundaries. This special issue was designed to stimulate innovative investigations of the relationship between social media and bu...

News aggregators have emerged as an important component of digital content ecosystems, attracting traffic by hosting curated collections of links to third-party content, but also inciting conflict with content producers. Aggregators provide titles and short summaries (snippets) of articles they link to. Content producers claim that their presence d...

An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-per-impression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are becoming the predominant method of selling advertising on the Internet. Well-kn...

Online reputation mechanisms harness the bi-directional communication capabilities of the Internet in order to engineer large-scale word-of-mouth networks. They are emerging as a promising alternative to more established assurance mechanisms, such as branding and formal contracting, in a variety of settings ranging from online marketplaces to Inter...

User-generated content has been hailed by some as a democratizing force that enables consumers to discuss niche products that were previously ignored by mainstream media. Nevertheless, the extent to which consumers truly prefer to use these new outlets to discuss lesser-known products as opposed to spending most of their energies on discussing wide...

A defining property of the World Wide Web is a content site's ability to place virtually costless hyperlinks to third-party content as a substitute or complement to its own content. Costless hyperlinking has enabled new types of players, usually referred to as content aggregators, to successfully enter content ecosystems, attracting traffic and rev...

We study settings where a number of sellers simultaneously offer vertically differentiated Vickrey auctions for imperfect substitute goods to unit-demand buyers. Vertical differentiation can arise from differences in item quality, item value certainty, seller reliability, or a combination of these factors. We characterize the form of the bidding eq...

Online Reputation Systems are a key, but under-appreciated, component of virtually every social web application. They play an important role in inducing user participation, good behavior and quality contributions. Despite their importance, however, their practical design and implementation has, so far, typically been the result of trial and error....

An important current trend in advertising is the replacement of traditional pay-per-exposure (pay-per-impression) pricing models with performance-based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action (PPA) mechanisms are be-coming the predominant method of selling advertising on the Internet. Well-k...

Google. Wikipedia. Threadless. All are platinum exemplars of collective intelligence in action. Two of them are famous. The third is getting there. Each of the three helps demonstrate how large, loosely organized groups of people can work together electronically in surprisingly effective ways sometimes even without knowing that they are working tog...

User-generated content platforms, open source software, crowdsourcing and knowledge markets - these are all possible only because of the "social web," the interlinked virtual universe that to so many executives seems to offer the irresistible promise of providing something - ideas, work, decisions - for (almost) nothing, if only they could manage i...

An important current trend in advertising is the replacement of traditional pay-per-exposure (aka pay-per-impression) pricing models with performance based mechanisms in which advertisers pay only for measurable actions by consumers. Such pay-per-action mechanisms are becoming the predominant method of selling advertising on the Internet. Well-know...

Over the past decade, the rise of the Internet has enabled the emergence of surprising new forms of collective intelligence. Examples include Google, Wikipedia, Threadless, and many others. To take advantage of the possibilities these new systems represent, it is necessary to go beyond just seeing them as a fuzzy collection of “cool” ideas. What is...

This paper studies settings where a number of sellers of different reputations for honesty simultaneously offer sealed-bid, second-price, single-unit auctions for imperfect substitute goods to unit-demand buyers. Among other applications, these settings can serve as an abstraction of large scale decentralized Internet auction marketplaces, such as...

Most online feedback mechanisms rely on voluntary reporting of privately observed outcomes. This introduces the potential for reporting bias, a situation where traders exhibit different propensities to report different outcome types to the system. Unless properly accounted for, reporting bias may severely distort the distribution of public feedback...

While there is a growing stream of research examining online sponsored search advertising, an important area that has not yet received enough attention is the interplay between pay-per-performance advertising and the quality of the firms who choose to invest in it. Our objective in this work is to explore how the shift from pay-for-exposure to pay-...

An important current trend in online advertising is the shift from traditional, "pay-per-exposure" mechanisms to, allegedly more efficient, "pay-per-action" methods, such as pay-per-click, pay-per-call and, in some cases, even pay-per-sale. While there is a growing stream of research examining sponsored search and other types of online advertising,...

By providing a platform where consumers can discuss obscure products not covered by mainstream media, user-centered media, such as online product review forums, are expected by many to reduce the informational inequality between hit and niche products and thus help shift demand towards the long tail of less popular products. Some researchers have c...

The growing popularity of online product review forums invites the development of models and metrics that allow firms to harness these new sources of information for decision support. Our work contributes in this direction by proposing a novel family of diffusion models that capture some of the unique aspects of the entertainment industry and testi...

The emergence of online communities has enabled firms to monitor consumer-generated online word-of-mouth (WOM) in real-time by mining publicly available information from the Internet. A prerequisite for harnessing this new ability is the development of appropriate WOM metrics and the identification of relationships between such metrics and consumer...

There is growing evidence that consumers are influenced by Internet-based opinion forums before making a variety of purchase decisions. Firms whose products are being discussed in such forums are, therefore, tempted to manipulate consumer perceptions by posting costly anonymous messages that praise their products. This paper oers a theoretical anal...

Reputation mechanisms have become an important component of electronic markets, helping to build trust and elicit cooperation among loosely connected and geographically dispersed economic agents. Understanding the impact of different reputation mechanism design parameters on the resulting market efficiency has, thus, emerged as a question of theore...

Online "feedback mechanisms" - also known as "reputation systems" - have been implemented in the most important private e-markets, such as eBay, Yahoo!, Amazon to foster trust and cooperation among trading partners. In this paper we discuss the main issues relevant for the optimal design of such mechanisms, providing practical indications for publi...

In this paper we describe PRELUDE, a programming language and accompanying system support for writing portable MIMD parallel programs. PRELUDE supports a methodology for designing and orga. nizing parallel programs that makes them easier to tune for particular architectures and to port to new architectures. It builds on earlier work on Emerald, Amb...

Reputation mechanisms harness the bi-directional communication capabilities of the Internet in order to engineer large-scale word-of-mouth networks. Best known so far as a technology for building trust and fostering cooperation in online marketplaces, such as eBay, these mechanisms are poised to have a much wider impact on organizations. This paper...

This paper offers a systematic exploration of reputation mechanism design in trading environments with opportunistic sellers of commonly known cost and ability parameters, imperfect monitoring of a seller's actions, and two possible seller effort levels, one of which has no value to buyers. The objective of reputation mechanisms in such pure moral...

Consumer choice is influenced in a direct and meaningful way by the actions taken by others. These “actions” range from face-to-face recommendations from a friend to the passive observation of what a stranger is wearing. We refer to the set of such contexts as “social interactions” (SI). We believe that at least some of the SI effects are partially...

Despite the widespread popularity of online opinion forums among consumers, the business value that such systems bring to organizations has, so far, remained an unanswered question. This paper addresses this question by studying the value of online movie ratings in forecasting motion picture revenues. First, we conduct a survey where a nationally r...

Despite the widespread popularity of online opinion forums among consumers, the business value that such systems bring to organizations has, so far, remained an unanswered question. This paper addresses this question by studying the value of online movie ratings in forecasting motion picture revenues. First, we conduct a survey where a nationally r...

This paper offers a systematic exploration of reputation mechanism design in trading environments with opportunistic sellers, imperfect monitoring of a seller's actions and two possible seller effort levels, one of which has no value to buyers. The objective of reputation mechanisms in such settings is to induce sellers to exert high effort as ofte...

There is growing evidence that consumers are influenced by Internet-based opinion forums before making a variety of purchase decisions. Firms whose products are being discussed in such forums are therefore tempted to try to manipulate consumer perceptions by injecting anonymous messages that praise their products or by offering incentives to consum...

Reputation systems are emerging as an increasingly important component of online communities, helping elicit good behavior and cooperation among loosely connected and geographically dispersed economic agents. A deeper understanding of the factors that drive voluntary online feedback contribution is crucial to the long-term viability of such systems...

Abstract ¶ Despite the widespread popularity of online opinion forums among consumers, the business value that such systems bring to organizations has, so far, remained an unanswered question. This paper addresses this question by studying the value of online movie ratings in forecasting

Several properties of online interaction are challenging the accumulated wisdom of trading communities on how to produce and manage trust. Online reputation systems have emerged as a promising trust management mechanism in such settings. The objective of this chapter is to contribute to the construction of online reputation systems that are robust...

Several properties of online interaction are challenging the accumulated wisdom of trading communities on how to produce and manage trust. Online reputation systems have emerged as a promising trust management mechanism in such settings. The objective of this chapter is to contribute to the construction of online reputation systems that are robust...

Software agent marketplaces require the development of new architectures, which are capable of coping with unreliable computational and network infrastructures, limited trust among independently developed agents and the possibility of systemic failures. In analogy with human societies, agent marketplaces will benefit from the introduction of approp...

Most online feedback mechanisms publish unbiased statistics (usually averages) of past ratings. Such mechanisms fail in environments where the same seller sells products of many different qualities, such as marketplaces of used cars and collectibles. This paper presents a novel feedback management mechanism that succeeds in facilitating efficient t...

This paper describes a novel knowledge-based methodology and toolset for helping business process designers and participants better manage exceptions (unexpected deviations from an ideal sequence of events caused by design errors, resource failures, requirement changes, etc.) that can occur during the enactment of a process. This approach is based...

This chapter describes a novel knowledge-based methodology and computer toolset for helping business process designers and participants better manage exceptions (unexpected deviations from a normal sequence of events caused by design errors, resource failures, requirement changes etc.) that can occur during the enactment of a process. This approach...

in online auction settings with noisy monitoring of quality and adverse selection. The mechanism combines the ability of electronic markets to solicit feedback from buyers with the more traditional ability to levy listing fees from sellers. Each period the mechanism charges a listing fee contingent on a seller's announced expected quality. It subse...

Online feedback mechanisms harness the bi-directional communication capabilities of the Internet in order to engineer large-scale word-of-mouth networks. Best known so far as a technology for building trust and fostering cooperation in online marketplaces, such as eBay, these mechanisms are poised to have a much wider impact on organizations. Their...

This paper offers a systematic exploration of online feedback mechanism design issues in trading environments with opportunistic sellers, imperfect monitoring of a seller's effort level, and two possible transaction outcomes (corresponding to "high" and "low" quality respectively), one of which has no value to buyers. The objective of feedback mech...

Commerce depends on buyers and sellers fulfilling their contractual obligations; mechanisms inducing such performance are essential to well-functioning markets. Internet-enabled reputation mechanisms that collect and disseminate consumer feedback have emerged as prominent means for inducing seller performance in online and offline markets. This pap...

Information systems for supporting the fluid organizations of the 21 st century must be correspondingly open and agile, able to automatically configure themselves out of heterogeneous system components, accommodate the dynamic exit and entry of hitherto unknown participants and maintain system stability in the face of limited trust. This paper intr...

This paper introduces a model for analyzing marketplaces, such as eBay, which rely on binary reputation mechanisms for quality signaling and quality control. In our model sellers keep their actual quality private and choose what quality to advertise. The reputation mechanism is primarily used to determine whether sellers advertise truthfully. Buyer...

makes experimental evaluation of parallel programs an important complement to theoretical analysis. Traditional techniques used to monitor the direct execution of programs are intrusive and may lead to inaccurate results when applied to parallel programs. Simulation allows flexible, nonintrusive and repeatable evaluation of parallel programs but us...

This paper describes a methodology that multi-agent system designers can use to identify, and find suitable responses for, potential failure modes (henceforth called 'exceptions') in multi-agent systems.

Several properties of online interaction are challenging the accumulated wisdom of trading communities on how to produce and manage trust. Online reputation reporting systems have emerged as a promising trust management mechanism in such settings. The objective of this paper is to contribute to the construction of online reputation reporting system...

ented scope to the deployment of relatively untried market mechanisms whose vulnerabilities have not been fully understood. Large-scale remote bidding has been enabled by ubiquitous telecommunications, for example, and combinatoric auctions have only recently made practical by the identification of tractable winning bid identification algorithms [5...

This paper addresses a critical question involved in the development of multi-agent systems: how can we create robust systems out of the often unreliable agents and infrastructures we can expect to find in open systems contexts? We propose an approach to this problem based on distinct exception handling (EH) services that enact coordination protoco...

In this paper we describe PRELUDE, a programming language and accompanying system support for writing portable MIMD parallel programs. PRELUDE supports a methodology for designing and orga. nizing parallel programs that makes them easier to tune for particular architectures and to port to new architectures. It builds on earlier work on Emerald, Amb...

MIMD architecture; the algorithm is particularly well suited for implementation on a small number of processors. We introduce a (2 B-2, 2 B) search tree that uses a linear array of O(log n) processors to store n entries. Update operations use a bottom-up node-splitting scheme, which performs better than top-down search tree algorithms. Additionally...

: This paper argues that component-based software development introduces additional sources of risk because (i) independently developed components cannot be fully trusted to conform to their published specifications and (ii) very often, software failures are caused by systemic patterns of interaction that cannot be localized to any individual compo...

Reputation reporting systems have emerged as an important risk management mechanism in online trading communities. However, the predictive value of these systems can be compromised in situations where conspiring buyers intentionally give unfair ratings to sellers or where sellers discriminate on the quality of service they provide to different buye...

This paper proposes an architecture for "closing the feedback loop" over the entire software evolution process and enabling the construction of self-evolving software systems. Self-evolving software systems are capable of automatically detecting when changing external circumstances or internal conditions can be better handled by alternate software...

This paper describes a novel knowledge-based approach for helping business process designers and participants better manage exceptions (deviations from an ideal sequence of events caused by design errors, resource failures, requirement changes etc.) that can occur during the enactment of a process. This approach is based on exploiting a generic and...

Reputation reporting systems have emerged as an important risk management mechanism in online trading communities. However, the predictive value of these systems can be compromised in situations where conspiring buyers intentionally give unfair ratings to sellers or, where sellers discriminate on the quality of service they provide to different buy...

Online reputation mechanisms are emerging as a promising alternative to more traditional trust building mechanisms, such as branding and formal contracting, in settings where the latter may be ineffective or prohibitively expensive; a lot of electronic trading communities fall under these categories. Although a number of commercial websites already...

Information systems for supporting the fluid organizations of the 21st century must be correspondingly open and agile, able to automatically configure themselves out of heterogeneous system components, accommodate the dynamic exit and entry of hitherto unknown participants and maintain system stability in the face of limited trust. This paper intro...

Social Order in Multiagent Systems provides an overview of current approaches, problems, and considerations related to the study of norms and institutions in the context of multiagent systems. The contributions in this volume share the assumption that norms and other social institutions are of vital importance for the development of multiagent syst...

: The objective of this paper is to contribute to the development of a rigorous discipline for designing trust management mechanisms in online communities. The importance of such a discipline for management science is without question: trust is a precondition for the continued existence of any market and organization in general. Furthermore, severa...

This paper describes a novel knowledge-based approachfor helping workflow process designers andparticipants better manage the exceptions (deviationsfrom an ideal collaborative work process caused byerrors, failures, resource or requirements changesetc.) that can occur during the enactment of aworkflow. This approach is based on exploiting ageneric...

. A critical challenge to creating effective open multi-agent systems is allowing them to operate effectively in the face of potential failures. In this paper we present an experimental evaluation of a set of domain-independent services designed to handle the failure modes ("exceptions") that can occur in such environments, applied to the wellknown...

. A critical challenge to creating effective multi-agent systems is allowing them to operate effectively in environments where failures (`exceptions') can occur. This paper describes the motivation, progress and plans for work being pursued in this area by the MIT Adaptive Systems and Evolutionary Software research group (http://ccs.mit.edu/ases/)....

Information systems for supporting the fluid organizations of the 21 st century must be correspondingly open and agile, able to automatically configure themselves out of heterogeneous system components, accommodate the dynamic exit and entry of hitherto unknown participants and maintain system stability in the face of limited trust. This paper intr...

A critical challenge to creating effective agent-based systems is allowing them to operate effectively when the operating environment is complex, dynamic, and error-prone. In this paper we will review the limitations of current "agent-local" approaches to exception handling in agent systems, and propose an alternative approach based on a shared exc...

. In the emerging model of 21st century electronic commerce, a variety of open agent marketplaces will be competing with one another for participants. The most successful marketplaces will be those that provide the best "quality of service" guarantees (in terms of security, fairness, efficiency, etc.), while meeting such challenges as agent heterog...

Software agent marketplaces require the development of new architectures, which are capable of coping with unreliable computational and network infrastructures, limited trust among independently developed agents and the possibility of systemic failures. In analogy with human societies, agent marketplaces will benefit from the introduction of approp...

A critical challenge to creating effective business processes is allowing them to operate effectively in environments where failures ('exceptions') can occur. An important barrier to achieving this has been the lack of systematized dissemination of exception handling techniques. This paper describes the MIT Exception Repository, a semi-formal Web-a...

In large software systems the identification and proper management of interdependencies among the pieces of a system becomes a central concern. Nevertheless, most traditional programming languages and tools focus on representing components, leaving the description and management of interdependencies among components implicit, or distributed among t...

. This chapter describes a novel knowledge-based methodology and computer toolset for helping business process designers and participants better manage exceptions (unexpected deviations from an ideal sequence of events caused by design errors, resource failures, requirement changes etc.) that can occur during the enactment of a process. This approa...

The creation of openagent-mediated electronic marketplaces requires new architectures, capable of copingwith unreliable computational and network infrastructures, limited trust among independentlydeveloped agents, and the possibility of systemic failures. In analogy with civil human societies, open marketplaces will benefit from the introduction of...

The workshop Towards Adaptive Workflow System was organized by the authors of this report as part of the 1998 Conference on Computer Supported Collaborative Work (CSCW-98), and was held at the Westin Seattle on Saturday, November 14, 1998. The workshop had about 30 attendees and included invited presentations, paPer presentations/discussions and a...

This paper provides a progress report on the development of softwaretools in the Process Handbook project currently underway at the MIT Center for Coordination Science. We begin with a brief overview of the project as a whole. Then we focus on softwaretools emphasizing aspects that relate to work#ow control. Finally, we conclude with a brief descri...

This paper describes a novel theoretical and empirical approach to tasks such as business process redesign and knowledge management. The project involves collecting examples of how different organizations perform similar processes, and organizing these examples in an on-line “process handbook.” The handbook is intended to help people: (1) redesign...

As the size and complexity of software systems grows, the identification and proper management of interconnections among the pieces of the system becomes a central concern. Nevertheless, many programming languages and tools today still place an emphasis on representing components, leaving the description and management of component interdependencie...