Software vulnerability due to practical drift

The proliferation of information and communication technologies (ICTs) into all aspects of life poses unique ethical challenges as our modern societies become increasingly dependent on the flawless operation of these technologies. As we increasingly entrust our privacy, our well-being and our lives to an ever greater number of computers we need to look more closely at the risks and ethical implications of these developments. By emphasising the vulnerability of software and the practice of professional software developers, we want to make clear the ethical aspects of producing potentially flawed software. This paper outlines some of the vulnerabilities associated with software systems and identifies a number of social and organisational factors affecting software developers and contributing to these vulnerabilities. Scott A. Snook’s theory of practical drift is used as the basis for our analysis. We show that this theory, originally developed to explain the failure of a military organisation, can be used to understand how professional software developers “drift away” from procedures and processes designed to ensure quality and prevent software vulnerability. Based on interviews with software developers in two Norwegian companies we identify two areas where social factors compel software developers to drift away from a global set of rules constituting software development processes and methods. Issues of pleasure and control and difference in mental models contribute to an uncoupling from established practices designed to guarantee the reliability of software and thus diminish its vulnerability.     

Learned suppression of photopositive tendencies in<Emphasis Type="Italic">Drosophila melanogaster</Emphasis>

A task was designed to teach individual flies to avoid a lighted area after they had displayed an initial preference for it. The flies walked in a T-maze and chose between a lighted and a darkened alley leading, respectively, to a lighted and a darkened vial. Flies that were photopositive on a first trial were subjected to an aversive stimulus (a filter paper inserted into the lighted vial and wetted with a quinine solution), and they performed 16 training trials; they learned to avoid the lighted vial. The flies trained with water instead of quinine in the lighted vial still displayed avoidance of the lighted vial, but to a lesser extent. The flies trained with a dry filter paper in the lighted vial did not show any increase in avoidance during training. Like the flies trained with no quinine at all, those trained to avoid the lighted vial under a partial reinforcement condition (one half of the trials with quinine, the other half with a dry vial) did not master the task. Finally, removal of the quinine after an avoidance acquisition criterion was reached resulted in an extinction process.     

Das MINERVA-Projekt: Datenbankselektion für Peer-to-Peer-Websuche

Zusammenfassung In diesem Artikel wird MINERVA pr?sentiert, eine prototypische Implementierung einer verteilten Suchmaschine basierend auf einer Peer-to-Peer (P2P)-Architektur. MINERVA setzt auf die in der P2P-Welt verbreitete Technik verteilter Hash-Tabellen auf und benutzt diese zum Aufbau eines verteilten Verzeichnisses. Peers in unserem Ansatz entsprechen v?llig autonomen Benutzern mit ihren lokalen Suchm"oglichkeiten, die bereit sind, ihr lokales Wissen und ihre lokalen Suchm?glichkeiten im Rahmen einer Kollaboration zur Verfügung zu stellen. Wir formalisieren unsere Systemarchitektur und beschreiben das zentrale Problem einer effizienten Suche nach vielversprechenden Peers für eine konkrete Anfrage innerhalb des Verbundes. Wir greifen dabei auf existierende Methoden zurück and passen diese an unseren Systemkontext an. Wir pr?sentieren Experimente auf realen Daten, die verschiedene dieser Ans?tze vergleichen. Diese Experimente zeigen, dass die Qualit?t der Ans?tze variiert und untermauern damit die Wichtigkeit und den Einfluss einer leistungsstarken Methode zur Auswahl guter Datenbanken. Unsere Experimente deuten an, dass eine geringe Anzahl sorgf?ltig ausgew?hlter Datenbanken typischerweise bereits einen Gro?teil aller relevanten Ergebnisse des Gesamtsystems liefert.

---

This paper presents the MINERVA project that protoypes a distributed search engine based on P2P techniques. MINERVA is layered on top of a Chord-style overlay network and uses a powerful crawling, indexing, and search engine on every autonomous peer. We formalize our system model and identify the problem of efficiently selecting promising peers for a query as a pivotal issue. We revisit existing approaches to the database selection problem and adapt them to our system environment. Measurements are performed to compare different selection strategies using real-world data. The experiments show significant performance differences between the strategies and prove the importance of a judicious peer selection strategy. The experiments also present first evidence that a small number of carefully selected peers already provide the vast majority of all relevant results.

CR Subject Classification H.4,H.3.3,H3.4     

Motion Pictures

Richard Bunce's Television in the Corporate Interest (New York: Praeger Special Studies, 1976—price not given, but about $15.00).

Ralph M. Jennings and Veronica M. Jefferson's Television Station Employment Practices, 1975: The Status of Minorities and Women (New York: Office of Communication, United Church of Christ, 1976—price not given, but about $10.00, paper)

Horace Newcomb's Television: The Critical View (New York: Oxford University Press, 1976—$4.00, paper)

Asa Berger's The TV-Guided American (New York: Walker, 1976—$8.95)

Vincent Mosco's The Regulation of Innovations in the Broadcasting Market (Cambridge, Mass.: Harvard University Program on Information Technologies and Public Policy, 1975—$3.00, paper)

James D. Scott's Cable Television: Strategy for Penetrating Key Urban Markets (Ann Arbor: University of Michigan Graduate School of Business Administration, 1976—$5.50, paper)

R.W. Chandler's Sparks at Sea: The Experiences of a Ship's Radio Officer (North Pomfret, Vt.: David and Charles, 1973, but only recently released in the U.S.—$9.50)     

Predictive value of ventilatory inflection points determined under field conditions

The aim of this study was to evaluate the predictive potential provided by two ventilatory inflection points (VIP₁ and VIP₂) examined in field without using gas analysis systems and uncomfortable facemasks. A calibrated respiratory inductance plethysmograph (RIP) and a computerised routine were utilised, respectively, to derive ventilation and to detect VIP₁ and VIP₂ during a standardised field ramp test on a 400 m running track on 81 participants. In addition, average running speed of a competitive 1000 m run (S_1k) was observed as criterion. The predictive value of running speed at VIP₁ (S_VIP1) and the speed range between VIP₁ and VIP₂ in relation to VIP₂ (VIP_SPAN) was analysed via regression analysis. VIP_SPAN rather than running speed at VIP₂ (S_VIP2) was operationalised as a predictor to consider the covariance between S_VIP1 and S_VIP2. S_VIP1 and VIP_SPAN, respectively, provided 58.9% and 22.9% of explained variance in regard to S_1k. Considering covariance, the timing of two ventilatory inflection points provides predictive value in regard to a competitive 1000 m run. This is the first study to apply computerised detection of ventilatory inflection points in a field setting independent on measurements of the respiratory gas exchange and without using any facemasks.     

Individual Differences in Fifth Graders’ Literacy and Academic Language Predict Comprehension Monitoring Development: An Eye-Movement Study

In this study, we investigated fifth graders’ (n = 52) fall literacy, academic language, and motivation and how these skills predicted fall and spring comprehension monitoring on an eye movement task. Comprehension monitoring was defined as the identification and repair of misunderstandings when reading text. In the eye movement task, children read two sentences; the second included either a plausible or implausible word in the context of the first sentence. Stronger readers had shorter reading times overall suggesting faster processing of text. Generally fifth graders reacted to the implausible word (i.e., longer gaze duration on the implausible vs. the plausible word, which reflects lexical access). Students with stronger academic language, compared to those with weaker academic language, generally spent more time rereading the implausible target compared to the plausible target. This difference increased from fall to spring. Results support the centrality of academic language for meaning integration, setting standards of coherence, and utilizing comprehension repair strategies.     

Improving Silent Reading Performance Through Feedback on Eye Movements: A Feasibility Study

This feasibility study investigated if feedback about individual eye movements, reflecting varying word processing stages, can improve reading performance. Twenty-five university students read 90 newspaper articles during 9 eye-tracking sessions. Training group participants (n = 12) were individually briefed before each session, which eye movement parameter(s) (fixation count, first fixation duration, regression, and/or skipping) to address, and informed about changes achieved in preceding sessions. Control group participants (n = 13) were told that self-instruction to read faster would produce training gains. Total fixation times decreased significantly more for training than for control group participants. Important to note, faster reading did not impair comprehension. Results are interpreted as first indications for a possible applicability of the feedback approach to silent reading. In addition to implications for future studies, alternative result interpretations (e.g., motivational effects, reduction of mindless reading) are discussed.