September 2009 - Vol. 52 No. 9

September 2009 issue cover image

Features

Opinion Editor's letter

The Financial Meltdown and Computing

For many of us, the past year has been one of the most unsettling in our lifetime. In the late 1980s and early 1990s, we watched communism collapse of its own dead weight. In late 2008, we saw capitalism nearly crumble. Lehman Brothers, a major U.S. investment bank, declared bankruptcy last September, sending the world's financial system into a tailspin. Only a massive intervention by central banks saved the system from collapse.
Opinion Letters to the editor

Computer Science Does Matter

It was disappointing that two competent computer scientists — Matthias Felleisen and Shiram Krishnamurthi — took such a narrow view in their Viewpoint "Why Computer Science Doesn't Matter" (July 2009).
News In the Virtual Extension

In the Virtual Extension

Communications' Virtual Extension brings more quality articles to ACM members. These articles are now available in the ACM Digital Library.
News

Medical Nanobots

Researchers working in medical nanorobotics are creating technologies that could lead to novel health-care applications, such as new ways of accessing areas of the human body that would otherwise be unreachable without invasive surgery.
Research and Advances Research highlights

Optimistic Parallelism Requires Abstractions

Writing software for multicore processors is greatly simplified if we could automatically parallelize sequential programs. Although auto-parallelization has been studied for many decades, it has succeeded only in a few application areas such as dense matrix computations. 
Research and Advances Research highlights

Spamalytics: An Empirical Analysis of Spam Marketing Conversion

We all receive spam advertisements, but few of us have encountered a person who admits to following through on an offer and making a purchase. And yet, the relentlessness by which such spam continually clogs Internet inboxes provides undeniable testament that spammers find their campaigns profitable.
Research and Advances Virtual extension

Examining User Involvement in Continuous Software Development

Ms. Perez was giving a PowerPoint presentation to her potential clients in the hope of landing a big contract. She was presenting a new advertising campaign for a mutual fund company and had spent three months with her team on perfecting the proposal. Everything seemed to be going well when suddenly a small window screen popped up informing her that an error had occurred and asked if she would wish to send an error report. She clicked the send button and the application on her laptop shut down, disrupting the flow of her presentation and making her look unprofessional. This story entails an example of a user's experience and response to a new method for collecting information on software application errors. To maintain a certain level of quality and ensure customer satisfaction, software firms spend approximately 50% to 75% of the total software development cost on debugging, testing, and verification activities. Despite such efforts, it is not uncommon for a software application to contain errors after the final version is released. To better manage the software development process in the long run firms are involving the users in software improvement initiatives by soliciting error information, while they are using the software application. The information collected through an error reporting system (ERS) plays an important role in uncovering bugs and prioritizing future development work. Considering that about 20% of bugs cause 80% of the errors, gathering information on application errors can substantially improve software firms' productivity and improve the quality of their products. High quality software applications can benefit the software users individually and also help improve the image of the software community as a whole. Thus, understanding the emerging error reporting systems (ERS) and why users adopt them are important issues that require examination. Such an analysis can help the software companies in learning how to design better ERS and educate the users about ERS and its utilities.
Research and Advances Virtual extension

Constructive Function-Based Modeling in Multilevel Education

It is a digital age, especially for children and students who can be called the world's first truly digital generation. Accordingly a new generation education technology with a particular emphasis on visual thinking and specific computer-based notions and means is emerging. This is a new challenge for computer graphics which is a wide discipline dealing with creating visual images and devising their underlying models. There have been two major paradigms in computer graphics, and shape modeling as its part, for a certain period of time: namely, approximation and discretization. Their purpose is to simplify ideal complex shapes to make it possible to deal with them using limited capabilities of hardware and software. The approximation paradigm includes 2D vector graphics, 3D polygonal meshes, and later approximations by free-form curves and surfaces. The discretization paradigm originated raster graphics, then volume graphics based on 3D grid samples, and recently point-based graphics employing clouds of scanned or otherwise generated surface points. The problems of the both paradigms are obvious: loss of precise shape and visual property definitions, growing memory consumption, limited complexity, and others. Surface and volumetric meshes, lying in the foundation of modern industrial computer graphics systems, are so cumbersome that it is difficult to create, handle, and even understand them. The need in compact precise models with unlimited complexity has lead to the newly emerging paradigm of procedural modeling and rendering. One of the possibilities to represent an object procedurally is to evaluate a real function representing the shape and other real functions representing object properties at the given point. Our research group proposed in a constructive approach to creation of such function evaluation procedures for geometric shapes and in extended the approach to the case of point attribute functions representing object properties. The main idea of this approach is the creation of complex models from simple ones using operations similar to a model assembly from elementary pieces in LEGO. In terms of educational technology, such an approach is very much in the spirit of a constructionism theory by Seimur Papert. The main principle of this theory is active learning when learners gain knowledge actively constructing artifacts external to themselves. Applications of this theory coupled with modern computer technologies are emerging although a relationship with educational practice is not always easy. It is known that constructive thinking lying in the heart of LEGO games enable children to learn notions that were previously considered as too complex for them. There was research at the MIT Media Laboratory that led to the LEGO MindStorms robotics kits allowing children build their own robots using "programmable bricks" with electronics embedded inside. We have been developing not physical but virtual modeling and graphics tools that make it possible to use an extensible suite of "bricks" (see illustration in Figure 1) with a possibility to deform and modify them on the fly. Such an approach assumes mastering the basic mathematical concepts, initial programming in a simple language with subsequent creating an underlying model, generating its images and finally fabricating a real object of that model. We believe it is of interest as an educational technology for not only children and students but also for researchers, artists, and designers. It is important that learners interacting with a created virtual world acquire knowledge not just about mathematics and programming but also about structures and processes of the real world. We found soon after the introduction of our approach to modeling in the mid-90s that none of existing modeling systems or languages support this paradigm. Another necessity was to start preparation of qualified students to be involved in the R&
Research and Advances Virtual extension

One Size Does Not Fit All: Legal Protection For Non-Copyrightable Data

The web has become the largest data repository on the planet. An important factor contributing to its success is its openness and ease of use: anyone can contribute data to, and consume data from, the Web. As Tim Berners-Lee, inventor of the Web, said, "the exciting thing is serendipitous reuse of data: one person puts data up there for one thing, and another person uses it another way." Such serendipitous data reuse is extremely valuable. Through reuse, new knowledge can be created, innovation and value-added services become possible. However, there have been efforts to regulate and legally challenge data reuse activities. The European Union (EU) has adopted the Database Directive to restrict unauthorized data extraction and reuse. In the U.S., Congress has considered six bills, all of which failed to pass into law. These legislative activities are summarized in Figure 1; more details are furnished later. The significant uncertainty and the international differences in database legislation have created serious challenges to the "serendipitous reuse of data." The dual purposes of this article, both related to the theme "one size does not fit all," are to: summarize the range of legislation in current use and proposed; and present an economic model for interpreting or recommending policy choices that depend on factors such as cost of database creation and level of database differentiation. As computing professionals continue to develop technologies (such as data extraction, Web mashups, Web services, and various Semantic Web technologies) to make data reuse much easier, it is important for us to understand the legal implications when applying these technologies for data reuse purposes.
Research and Advances Virtual extension

The State of Corporate Website Accessibility

Web accessibility continues to have important social, legal and economic implications for ecommerce. Over 50 million Americans have disabilities and so do around 600 million world-wide (www.census.gov/prod/2003pubs/c2kbr-17.pdf; www.usdoj.gov/crt/ada/busstat.htm). Disabilities include a vast range of issues: cognition, vision, motor skills, and hearing. The disabled comprise 19.3% of the U.S. population, more than any other minority group, including the next largest group---Hispanics (14.9%). This growing population commands significant discretionary funds. The U.S. Department of Labor estimates those with disabilities control $175 billion (www.dol.gov/odep/pubs/ek98/provide.htm) exceeding twice that of teens and 17 times that of tweens (8--12 year-olds), currently the most sought after demographic groups (www.census.gov/prod/2003pubs/c2kbr-17.pdf). This untapped, growing market exceeds most company's estimations. In this study, we extend a previous CACM paper that surveyed accessibility at a snapshot in time with historical and additional perspectives on accessibility of Fortune 100 (F100) Web sites. The initial study revealed that over 80% of the F100's websites were potentially inaccessible to people with visual disabilities. Companies have become more aware of accessibility in recent years, which leads one to wonder whether the predominance of inaccessible websites continues or if companies have actually begun to seriously address website accessibility. Researchers have called for accessibility reviews over time. Following these suggestions, in addition to the initial study sample this study adds three additional data sets for a total of four: 2000, 2002, 2004, and 2005. The F100 Web sites were chosen for the usual reasons this population is studied, but also because we expect the largest and most profitable companies to be the most likely to have the resources and personnel to ensure website accessibility. The unit of analysis was the top-level home page for each Web site. This is an optimistic approach as companies may put their best foot forward here and then fail to consider accessibility for lower level pages. Deeper level analyses are possible but beyond the scope of this study. All samples were analyzed with the Watchfire® Bobby™ 5.0 Web accessibility validation tool. The Web Accessibility Initiative (WAI) guidelines were used to review all error types: Priority 1 (developers must satisfy), Priority 2 (developers should satisfy), and Priority 3 (developers may satisfy) (Table 1). WAI guidelines are a good starting point from which to evaluate Web accessibility and they are quickly becoming the global standard. WAI guidelines focus predominantly on problems encountered by blind users and therefore following only these guidelines will not always ensure accessibility for all disabled people. Given the breadth of existing disabilities it is difficult to evaluate all possible limitations to website accessibility. For this reason and to remain consistent with the previous study, this research concentrates on the WAI guidelines and thus issues that primarily impact visually impaired users. Automatically identified errors are important, yet many Web site accessibility problems must be checked manually by users or developers. For example, as the first criteria under Priority 1 suggests in Table 1, an accessible website should "provide alternative text for all images." Automated checkers cannot determine if the alternative text provided is meaningful to the user. Similarly, blind users often encounter problems with unlabeled "forms" that would allow them to enter information that could be searched, such as an author or title to a book. Further, 'user checks' may be more important than automatically validated errors because they can hide more subtle, yet potentially more problematic issues. We ran an automated user check analysis to determine the
Research and Advances Virtual extension

Reducing Employee Computer Crime Through Situational Crime Prevention

Information security has become increasingly important for organizations, given their dependence on ICT. Not surprisingly, therefore, the external threats posed by hackers and viruses have received extensive coverage in the mass media. Yet numerous security surveys also point to the 'insider' threat of employee computer crime. In 2006, for example, the Global Security Survey by Deloitte reports that 28% of respondent organizations encountered considerable internal computer fraud. This figure may not appear high, but the impact of crime perpetrated by insiders can be profound. Donn Parker argues that 'cyber-criminals' should be considered in terms of their criminal attributes, which include skills, knowledge, resources, access and motives (SKRAM). It is as a consequence of such attributes, acquired within the organization, that employers can pose a major threat. Hence, employees use skills gained through their legitimate work duties for illegitimate gain. A knowledge of security vulnerabilities can be exploited, utilising resources and access are provided by companies. It may even be the case that the motive is created by the organization in the form of employee disgruntlement. These criminal attributes aid offenders in the pursuit of their criminal acts, which in the extreme can bring down an organization. In the main, companies have addressed the insider threat through a workforce, which is made aware of its information security responsibilities and acts accordingly. Thus, security policies and complementary education and awareness programmes are now commonplace for organizations. That said, little progress has been made in understanding the insider threat from an offender's perspective. As organizations attempt to grapple with the behavior of dishonest employees, criminology potentially offers a body of knowledge for addressing this problem. It is suggested that Situational Crime Prevention (SCP), a relative newcomer to criminology, can help enhance initiatives aimed at addressing the insider threat. In this article, we discuss how recent criminological developments that focus on the criminal act, represent a departure from traditional criminology, which examines the causes of criminality. As part of these recent developments we discuss SCP. After defining this approach, we illustrate how it can inform and enhance information security practices. In recent years, a number of criminologists have criticised their discipline for assuming that the task of explaining the causes of criminality is the same as explaining the criminal act. Simply to explain how people develop a criminal disposition is only half the equation. What is also required is an explanation of how crimes are perpetrated. Criminological approaches, which focus on the criminal act, would appear to offer more to information security practitioners than their dispositional counterparts. Accordingly, the SCP approach can offer additional tools for practitioners in their fight against insider computer crime.
Research and Advances Virtual extension

Ballot Box Communication in Online Communities

The participation of individual users in online communities is one of the most noted features in the recent explosive growth of popular online communities ranging from picture and video sharing (Flickr.com and YouTube.com) and collective music recommendation (Last.fm) to news voting (Digg. com) and social bookmarking (del.icio.us). Unlike traditional online communities, these sites feature little message exchange among users. Nevertheless, users' involvement and their contribution through non-message-based interactions have become a major force behind successful online communities. Recognition of this new type of user participation is crucial to understanding the dynamics of online social communities and community monetization. The new communication features in online communities can be best summarized as Ballot Box Communication (BBC), which is an aggregation mechanism that reflects the common experience and opinions among individuals. By offering a limited number of choices such as voting, rating and tagging, BBC creates a new medium to effectively reveal the interests of mass population (see Table 1). Compared with traditional Computer Mediated Communication (CMC) such as email, Web publishing, and online forums, BBC influences user preferences by simplifying the mass sharing of individual preferences. These technologies offer new ways for information consumers to be involved in community activities. In traditional online communities, users only have two levels of participation: "watching from the sidelines" or "playing in the game," for example, they are either passive readers or active participants in conversations. However, BBC presents a new choice -- "shouting from the stands" -- in which each user can express his opinion through BBC and their collective preferences can be heard as a dominant voice. For instance, Digg readers can vote on news and promote it to the front page for millions of visitors to see. In spite of the increasing significance of non-message-based online communication, very little is known about BBC-enabled communities. As entrepreneurs build and manage new online communities, they have no choice but to look for the "right" technologies by trial-and-error. Not surprisingly, the result is hit-or-miss: some of the grandest failures of the dot com bust featured online communities. Only after costly failures, it has been recognized that not all technologies can benefit the growth and sustainability of a community. Extant theories on online communities and communication networks may offer some guidance on understanding of the emergence of new online communities (such as YouTube). Whitaker et al. identify online communities as "intense interactions, strong emotional ties and shared activities." In addition, Monge and Contractor define communication networks as "the patterns of contact that are created by the flow of messages among communicators through time and space." Both study the social interaction aspect of communities such as user commenting and discussing. However, the nonsocial interaction aspect, which is the focus of BBC and often dominant in contemporary online communities, has not received much attention.
Research and Advances Virtual extension

Modified Agile Practices For Outsourced Software Projects

Frustration with the bureaucratic nature of the disciplined approach has led to the call for agile development. The new approach is defined by the Agile Manifesto (http://agilemanifesto.org/), which values individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and agility in responding to change over following a prescribed plan. Agile development does not focus on process improvement; instead it focuses on customer satisfaction and employee empowerment. This is evident from reading the stated values and principles of the Agile Manifesto, which include fairly extreme positions such as "welcome changing requirements, even late in development" and "the best architectures, requirements, and designs emerge from self-organizing teams." An interesting issue arising from the call for agile development is its role in distributed development, which usually translates to offshore development. A recent study indicates that agile practices can reduce temporal, geographical, and socio-cultural distances in distributed development projects. The study researched agile development between teams located in the U.S. and Ireland, and while it reported that overall communication was improved, it also noted problems related to geographical, temporal, and even language distances. Although there are other reported successes of distributed agile development, the projects are generally small, the team members are likely familiar with each other, and the participants are largely experts or high caliber developers. This raises a research, as well as a practical, question: can we extend the use of agile practices from small projects to medium and large projects that involve a significant outsourcing component? To address this question, we must drop constraints such as small size projects, and expert developers belonging to the same company, and examine problems arising from geographical, temporal, and cultural distances. Accordingly, agile practices may need to be modified. In this article, the key issues of software projects with an outsourced component are first identified. These issues are then used as a background to evaluate how standard agile practices stand up when applied to larger projects. This evaluation is followed by recommendations for modified agile practices for outsourced software projects.
Research and Advances Virtual extension

Falling Into the Net: Main Street America Playing Games and Making Friends Online

In 1999, the National Telecommunications and Information Administration report Falling through the Net noted that "NTIA has found that there is still a significant "digital divide" separating American information "haves" and "have nots." Indeed, in many instances, the digital divide has widened in the last year." From the Internet's earliest days, there has been concern about its possible pernicious social effects. Even as millions began Internet surfing, critics averred the Internet was also harming users by destroying social interaction and eroding community involvement. Yet we may ask, what have been the experiences of the bulk of Internet users? Have they experienced loss of friends and involvement in the world due to Internet use, as claimed? Has their social world become hollow? These questions need to be addressed with the best data available. We are trying to answer these questions as part of the Syntopia Project, which has tracked growth and influence in ordinary life of the Internet since the mid-1990s. The Project's basic conclusion in 2002 was that the online and off-line world are becoming blended, and that concerns about lack of community are overblown. This view has been further reinforced by results from our most recent survey. In February and March, 2007, we conducted a nationally representative survey of 1404 Americans 18 years of age and older. This survey explored several dimensions of the way people are using the Internet, including how much they are involved in games and online simulations, their feelings of community, and the extent to which they are making online friendships, including friendships that migrate from the virtual world to the physical world. We found that 67% of respondents (N = 943) were Internet users (compared to the 71% reported by the Pew Internet in American Life Project, and the 70% reported by Internet World Stats, (both of which included people below the age of 18). Surprisingly, in light of all the concern about a gender gap in terms of Internet usage, there were almost identical levels of usage by men and women (a trend that we discerned as early as our 2000 survey). Many respondents use the Internet intensively. About one out of three respondents say they spend three or more hours on the Internet in a typical day, while two thirds of users spend one or two hours a day (47% estimate one hour a day, and 20% estimate two hours per day). 28% estimate they use it between three to nine hours per day, and 5% are online more than nine hours a day. There were no significant differences between males and females across these levels of Internet usage. Given its image as something that only teens do (and that we only surveyed those 18 or older), our results showed that multiplayer gaming is thriving with 9.7% of Internet users playing them. We asked "Do you play online games that involve other players? Like Second Life, World of Warcraft or the SIMS"? Males (5.4%) play them in slightly greater proportion than females (4.3%). At the Internet's outset, there was much concern about the isolating and potentially depressing effects of the Internet. While our 2007 survey did not definitively address these questions, it did find that one-fifth of Internet users consider themselves to be "a member of an online community." There was practically no difference between males and females in the answers to this question. Moreover, there was very little difference between the genders in terms of how many friends they made online -- a median of about five. In fact, far from isolating people from social interaction, the Internet is a source of new face-to-face friendships, perhaps restoring some of the sociability that has been eroded due to television and suburbia (as argued persuasively by Putnam in Bowling Alone [2001]). As Table 1 shows, the Internet has spawned many new virtual friendships.

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