Anonymizing binary and small tables is hard to approximate

The problem of publishing personal data without giving up privacy is becoming increasingly important. An interesting formalization recently proposed is the k-anonymity. This approach requires that the rows in a table are clustered in sets of size at least k and that all the rows in a cluster become the same tuple, after the suppression of some records. The natural optimization problem, where the goal is to minimize the number of suppressed entries, is known to be NP-hard when the values are over a ternary alphabet, k=3 and the rows length is unbounded. In this paper we give a lower bound on the approximation factor that any polynomial-time algorithm can achieve on two restrictions of the problem, namely (i) when the records values are over a binary alphabet and k=3, and (ii) when the records have length at most 8 and k=4, showing that these restrictions of the problem are APX-hard.     

Comment on organizing in the crowd

This short article comments on Bennet's and Segerberg's work on connecting action. After singling out some conditions which, according to social movement studies, would make an aggregating logic and personalized messages very important for mobilization, the author calls for further research (including through qualitative methods) on the complex dynamics related to the contemporary use of various formats of communication by social movement activists.     

Nationwide Newspaper Coverage of Immigration Reform: A Community Structure Approach

A community structure analysis compared community characteristics and nationwide coverage of immigration reform in newspapers in 21 major U.S. cities, sampling all 250+ word articles April 23, 2010 to November 12, 2013. The resulting 262 articles were coded for “prominence” and “direction” (“favorable,” “unfavorable,” or “balanced/neutral” coverage), then combined into each newspaper's composite “Media Vector” (range = .632 to ?.4800). Nineteen of 21 newspapers showed favorable coverage of immigration reform. Pearson correlations yielded 4 significant results, the most powerful of which supported immigration reform. The “vulnerability” hypothesis (media “mirror” the interests of marginal/disadvantaged groups) was essentially confirmed. Higher percentages below the poverty line (r = .607, p = .003) and higher crime rates (r = .490, p = .017) correlated with more favorable coverage of immigration reform. By contrast, higher percentages of women in the workforce (r = ?.543, p = .008) and higher proportions of hate crimes (r = ?.403, p = .048) were linked with less favorable coverage. Regression analysis yielded the percentage living below the poverty line accounting for 37.2% of the variance, and proportion of hate crimes yielded an additional 19.1% of the variance. The Midwest had by far the most favorable coverage of immigration reform, more than any other region.     

The ‘importance of staying put’: third country nationals’ limited intra-EU mobility rights

The cautious approach of European Legislators towards the integration of non-EU third country nationals (TCNs), mirrored in the provisions of Long-Term Residence Directive 2003/109/EC, has brought about the creation of ‘spatial temporal waiting zones’. Migrants are confined in both place and time before being able to access the (as of yet, very limited) mobility rights conferred upon them by the Directive. Restricted mobility rights for TCNs can seriously impinge on the economic growth of the EU. This paper reveals three ‘faults’ of the current system. First, we show how TCNs already evade ‘temporal borders’ by moving across geographical ones to take up employment before being entitled to do so under the provisions of the Directive. Next, we show how formal integration in one member state (MS), paradoxically, opens the door to another MS and, third, how a second MS fights off these near-EU citizens. Finally, we observe the importance of taking the phenomenon of spatial and temporal waiting zones into account, not only when structuring intra-EU mobility policies for TCNs but also when addressing the issue of the (labour market) integration of recent arrivals: soon they too will become European long-term residents.     

A developmental perspective of gambling behavior in children and adolescents

Although it has been determined that gambling is a popular activity amongst the young, there seems to be a lack of studies examining developmental differences in children's gambling behavior. This study examines developmental differences in children's blackjack gambling behavior. One hundred and four students (51 males; 53 females) from grades 4, 6, and 8 completed a questionnaire examining their gambling behavior in general and individually played a computerized blackjack game with the following data being recorded: percentage of accuracy, amounts of money bet, gross winnings, percentage of wins, number of hands played, and end balance. Findings revealed few developmental differences in prevalence and frequency of gambling behavior and performance on a blackjack task. Males were found to wager greater amounts of money and have larger gross winnings than females on the blackjack task. Furthermore, males were more likely to view gambling as involving both large amounts of skill and luck, thus suggesting an illusion of control for gambling activities. The results are discussed from a cognitive developmental perspective.This research was partially supported by a grant from the McGill University Social Science Computer Committee. The authors would like to thank the administration, staff, and students in T.H. Bowes, Prince Charles, Souvenir, Gerald McShane, Our Lady of Pompei, Pierrefond Comprehensive High School, and Western Laval High School, for their participation and cooperation in this study.This is a revision of a paper presented at the Ninth International Conference on Gambling and Risk-Taking, Las Vegas, 1994.     

Helpful actions seen through the eyes of parents of children with disabilities

Parents of children with disabilities interact with a wide range of service providers in order to assure appropriate services for their children. While some actions performed by professionals are viewed as helpful, many are viewed as obstructive. Surveys completed by over 120 parents identified past actions perceived to be helpful and those thought to be unhelpful as well as identification of professionals associated with those actions. Using the critical incident technique, narrative responses were based on actual experiences that parents described. Parents were also asked to articulate specific actions they would like professionals to take in the future. Over half of the responses request desired relationships with professionals that focus on respect, collaboration, communication and information sharing. Implications for pre-professional training are discussed.