Why Is the Shape of the Web a Bowtie?

The first time in Graph Theory a graph was characterized as “Bowtie” was in the seminal paper by Broder et. al. Though no textbook had ever mentioned this type of graph before, no less an important network than the Web Graph itself is supposed to resemble this shape. In two large collections of crawled Web pages and in numerous smaller collections, researchers discovered Bowties and Bowtie-looking graphs by studying millions of web pages. But why do collections of Web pages resemble a Bowtie? The short answer is “because, given the way the Web is created, that’s the only shape it could have”. This paper shows why this is the case and presents an algorithm and software to visualize Bowtie graphs

A 2007 Model Curriculum for a Liberal Arts Degree in Computer Science

In 1986, guidelines for a computer science major degree program offered in the context of the liberal arts were developed by the Liberal Arts Computer Science Consortium (LACS) [4]. In 1996 the same group offered a revised curriculum reflecting advances in the discipline, the accompanying technology, and teaching pedagogy [6]. In each case, the LACS models represented, at least in part, a response to the recommendations of the ACM/IEEE-CS [1][2]. Continuing change in the discipline, technology, and pedagogy coupled with the appearance of Computing Curriculum 2001 [3] have led to the 2007 Model Curriculum described here. This report begins by considering just what computer science is and what goals are appropriate for the study of computer science in the landscape of the liberal arts. A curricular model for this setting follows, updating the 1996 revision. As in previous LACS curricula, [4] and [6], the model is practical; that is, students can schedule it, it can be taught with a relatively small size faculty, and it contributes to the foundation of an excellent liberal arts education. Finally, this 2007 Model Curriculum is compared with the recommendations of CC2001 [3]

Technology, Propaganda, and the Limits of Human Intellect

Fake news is a recent phenomenon, but misinformation and propaganda are not. Our new communication technologies make it easy for us to be exposed to high volumes of true, false, irrelevant, and unprovable information. Future AI is expected to amplify the problem even more. At the same time, our brains are reaching their limits in handling information. How should we respond to propaganda? Technology can help, but relying on it alone will not suffice in the long term. We also need ethical policies, laws, regulations, and trusted authorities, including fact­checkers. However, we will not solve the problem without the active engagement of the educated citizen. Epistemological education, recognition of self biases and protection of our channels of communication and trusted networks are all needed to overcome the problem and continue our progress as democratic societies

Sifting the Sand on the River Bank: Social Media as a Source for Research Data

Computational social science has been described as a new field at the intersection of computer science and social sciences, aiming to study the ways that society evolves, interacts, and reacts. Like prospectors sifting the sand in a river bed for gold, computational social science researchers are looking into the streams of social media for insight on our social interactions. Enabled by the availability of and easy accessibility to vast amounts of data generated by social entities, as well as by powerful computing hardware and algorithms, its researchers conduct observations of social interaction and experiments testing social theories in scales not realizable before. In this paper, after a short review of the characteristics of this new area, we discuss issues related to the types of data sought and used, and some of the challenges in collecting and interpreting the data. Throughout the paper we also examine some of the pitfalls awaiting and the standards that need to be observed

The Rise and the Fall of a Citizen Reporter

Recently, research interest has been growing in the development of online communities sharing news and information curated by “citizen reporters”. Using “Big Data” techniques researchers try to discover influence groups and major events in the lives of such communities. However, the big picture may sometimes miss important stories that are essential to the development and evolution of online communities. In particular, how does one identify and verify events when the important actors are operating anonymously and without sufficient news coverage, as in drug war-torn Mexico? In this paper, we present some techniques that allow us to make sense of the data collected, identify important dates of significant events therein, and direct our limited resources to discover hidden stories that, in our case, affect the lives and safety of prominent citizen reporters. In particular, we describe how focused analysis enabled us to discover an important story in the life of this community involving the reputation of an anonymous leader, and how trust was built in order to verify the validity of that story

Also Your Job to Learn! Helping Students to Reflect on their Learning Progress

Most of the time, the pedagogical analysis on student learning is focused on the efforts of the teacher. There is no doubt that teacher actions can have a profound positive e ffect on student learning. In this paper, we discuss what students can do to increase their learning outcome. In particular, we describe an instrument that facilitates students\u27 reflection of their own learning. Although the use of reflection on learning is not novel, its use in CS education has not been explored extensively. Our system was developed as a result of an experiment that we performed in a CS2 course, successfully giving students opportunities to take control of their own learning process. One of the attractive features of our system is that it is relatively easy for the instructor to set up and monitor the students\u27 progress. In our evaluation of the system, we found that it can increase significantly the students\u27 programming confidence at the end of the course. Even though this paper studies the eff effectiveness of introducing the reflection questionnaires instrument in a CS2-type course, it can be applied to most other courses in a curriculum. We provide the material we used in our experiment so that they can be adopted by educators

From Obscurity to Prominence in Minutes: Political Speech and Real-Time Search

Recently, all major search engines introduced a new feature: real-time search results, embedded in the first page of organic search results. The content appearing in these results is pulled by Twitter, blogs, and news websites within minutes of its generation. In this paper, we argue that in the context of political speech, this feature provides disproportionate exposure to personal opinions, fabricated content, unverified events, lies and misrepresentations that would otherwise not find their way in the first page, giving them the opportunity to spread virally. We provide evidence from the recent Massachusetts senate race between Martha Coakley and Scott Brown, analyzing attacks launched inside Twitter

A Parallel Algorithm for Computing Minimum Spanning Trees

We present a simple and implementable algorithm that computes a minimum spanning tree of an undirected weighted graph G = (V, E) of n = |V| vertices and m = |E| edges on an EREW PRAM in O(log 3=2 n) time using n+m processors. This represents a substantial improvement in the running time over the previous results for this problem using at the same time the weakest of the PRAM models. It also implies the existence of algorithms having the same complexity bounds for the EREW PRAM, for connectivity, ear decomposition, biconnectivity, strong orientation, st-numbering and Euler tours problems