Various activities move online in the era of the digital economy. Platform design and policy can heavily affect online user activities and result in many expected and unexpected consequences. In this dissertation, I conduct empirical studies on three types of online platforms to investigate the influence of their platform policy on their user engagement and associated outcomes. Specifically, in Study 1, I focus on goal-directed platforms and study how the introduction of the mobile channel affects users’ goal pursuit engagement and persistence. In Study 2, I focus on social media and online communities. I study the introduction of machine-powered platform regulation and its impacts on volunteer moderators’ engagement. In Study 3, I focus on online political discourse forums and examine the role of identity declaration in user participation and polarization in the subsequent political discourse. Overall, my results highlight how various platform policies shape user behavior. Implications on multi-channel adoption, human-machine collaborative platform governance, and online political polarization research are discussed.

In the era of big data, the impact of information technologies in improving organizational performance is growing as unstructured data is increasingly important to business intelligence. Daily data gives businesses opportunities to respond to changing markets. As a result, many companies invest lots of money in big data in order to obtain adverse outcomes. In particular, analysis of commercial websites may reveal relations of different parties in digital markets that pose great value to businesses. However, complex e­commercial sites present significant challenges for primary web analysts. While some resources and tutorials of web analysis are available for studying, some learners especially entry­level analysts still struggle with getting satisfying results. Thus, I am interested in developing a computer program in the Python programming language for investigating the relation between sellers’ listings and their seller levels in a darknet market. To investigate the relation, I couple web data retrieval techniques with doc2vec, a machine learning algorithm. This approach does not allow me to analyze the potential relation between sellers’ listings and reputations in the context of darknet markets, but assist other users of business intelligence with similar analysis of online markets. I present several conclusions found through the analysis. Key findings suggest that no relation exists between similarities of different sellers’ listings and their seller levels in rsClub Market. This study can become a great and unique example of web analysis and create potential values for modern enterprises.

Research has found there is a lack of women present in the IS industry. In order to combat this problem, this research examines why women are not choosing IS majors at the university level. At Arizona State University, the Computer Information Systems undergraduate degree program is only 23 percent female. Many different factors can influence the decision to choose a major, so survey methodology was used to ascertain what factors were the most important to different demographic groups when making this decision. The study found no significant gender difference when making this decision, but rather a difference between specific majors. Genuine interest, interesting work and high career earnings were identified as the most influential reasons for choosing a college major. The results were used to create recommendations for the IS Department at ASU to implement in the next year and encourage more female participation in the CIS undergraduate degree program.

Prenatal care is a widely administered preventative care service, and its adequate use has been shown to decrease poor infant and maternal health outcomes. Today however, in the United States, preterm birth rates remain among the highest in the industrialized world, with low socioeconomic women having the highest risk of preterm births. This group of women also face the greatest barriers to access adequate prenatal care in the United States. This paper explores the viability of short message service to help bridge gaps in prenatal care for low socioeconomic women in the United States and provides areas for further research.

Considering the overwhelming prevalence of BPH, how can it best be managed in light of the aging population? The purpose of this investigation is to illustrate that BPH and LUTS are conditions that are highly conducive to health literacy technology interventions. This objective will be met by: a) Providing an overview of the clinically relevant information regarding BPH, including anatomy, physiology, epidemiology, symptoms, and medical treatment for the disease; b) Establishing the necessity for novel health care delivery solutions by identifying past successes and challenges associated with technologic advances in related fields; c) Providing evidence of a lack of a systematic approach to BPH education, especially as it relates to health literacy. The relative successes and failures of previously established clinical decision aids will be discussed, leading to recommendations on how to improve upon these standards. Finally, the procedures and results of a pilot study will be analyzed in an effort to further highlight the necessity of engaging patients in the clinical decision making process.

Cyber-weapons and the rapid progression of utilizing cyberspace in conflict poses several risks to states and their ability to maintain control of their respective technological infrastructures. Susceptibility to these weapons extend to virtually all existing nations, and indicates a critical need for transnational organizations and their members to establish collective strategies for governing cyber-arms. In this paper, the United Nations, as a prime example of an influential transnational organization, is utilized as a case study for a framework that seeks to define and establish guidelines for arms control policy as it relates to cyber-weapons. Presented is a strategy that seeks to define cyber-warfare and cyber-weapons, distinguish it from other existing forms of weapons and warfare, and outline recommended actions for the United Nations and its affiliates, including the United Nations Office for Disarmament Affairs and United Nations Security Council.

Access control has been historically recognized as an effective technique for ensuring that computer systems preserve important security properties. Recently, attribute-based

access control (ABAC) has emerged as a new paradigm to provide access mediation

by leveraging the concept of attributes: observable properties that become relevant under a certain security context and are exhibited by the entities normally involved in the mediation process, namely, end-users and protected resources. Also recently, independently-run organizations from the private and public sectors have recognized the benefits of engaging in multi-disciplinary research collaborations that involve sharing sensitive proprietary resources such as scientific data, networking capabilities and computation time and have recognized ABAC as the paradigm that suits their needs for restricting the way such resources are to be shared with each other. In such a setting, a robust yet flexible access mediation scheme is crucial to guarantee participants are granted access to such resources in a safe and secure manner.

However, no consensus exists either in the literature with respect to a formal model that clearly defines the way the components depicted in ABAC should interact with each other, so that the rigorous study of security properties to be effectively pursued. This dissertation proposes an approach tailored to provide a well-defined and formal definition of ABAC, including a description on how attributes exhibited by different independent organizations are to be leveraged for mediating access to shared resources, by allowing for collaborating parties to engage in federations for the specification, discovery, evaluation and communication of attributes, policies, and access mediation decisions. In addition, a software assurance framework is introduced to support the correct construction of enforcement mechanisms implementing our approach by leveraging validation and verification techniques based on software assertions, namely, design by contract (DBC) and behavioral interface specification languages (BISL). Finally, this dissertation also proposes a distributed trust framework that allows for exchanging recommendations on the perceived reputations of members of our proposed federations, in such a way that the level of trust of previously-unknown participants can be properly assessed for the purposes of access mediation.

The recent changes in the software markets gave users an unprecedented number

of alternatives for any given task. In such a competitive environment, it is imperative

to understand what drives user behavior. To that end, the research presented in

this dissertation, tries to uncover the impact of business strategies often used in the

software markets.

The dissertation is organized into three distinct studies into user choice and post

choice use of software. First using social judgment theory as foundation, zero price

strategies effects on user choice is investigated, with respect to product features,

consumer characteristics, and context effects. Second, role of social features in

moderating network effects on user choice is studied. And finally, the role of social

features on the effectiveness of add-on content strategy on continued user engagement

is investigated.

The findings of this dissertation highlight the alignments between popular business

strategies and broad software context. The dissertation contributes to the litera-

ture by uncovering hitherto overlooked complementarities between business strategy

and product features: (1) zero price strategy enhances utilitarian features but not

non-utilitarian features in software choice, (2) social features only enhance network

externalities but not social influence in user choice, (3) social features enhance the

effect of add-on content strategy in extending software engagement.

Mobile applications (Apps) markets with App stores have introduced a new approach to define and sell software applications with access to a large body of heterogeneous consumer population. Several distinctive features of mobile App store markets including – (a) highly heterogeneous consumer preferences and values, (b) high consumer cognitive burden of searching a large selection of similar Apps, and (c) continuously updateable product features and price – present a unique opportunity for IS researchers to investigate theoretically motivated research questions in this area. The aim of this dissertation research is to investigate the key determinants of mobile Apps success in App store markets. The dissertation is organized into three distinct and related studies. First, using the key tenets of product portfolio management theory and theory of economies of scope, this study empirically investigates how sellers’ App portfolio strategies are associated with sales performance over time. Second, the sale performance impacts of App product cues, generated from App product descriptions and offered from market formats, are examined using the theories of market signaling and cue utilization. Third, the role of App updates in stimulating consumer demands in the presence of strong ranking effects is appraised. The findings of this dissertation work highlight the impacts of sellers’ App assortment, strategic product description formulation, and long-term App management with price/feature updates on success in App market. The dissertation studies make key contributions to the IS literature by highlighting three key managerially and theoretically important findings related to mobile Apps: (1) diversification across selling categories is a key driver of high survival probability in the top charts, (2) product cues strategically presented in the descriptions have complementary relationships with market cues in influencing App sales, and (3) continuous quality improvements have long-term effects on App success in the presence of strong ranking effects.