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.     

Efficiency of Targeted Multistage Calibration Designs Under Practical Constraints: A Simulation Study

Calibration of an item bank for computer adaptive testing requires substantial resources. In this study, we investigated whether the efficiency of calibration under the Rasch model could be enhanced by improving the match between item difficulty and student ability. We introduced targeted multistage calibration designs, a design type that considers ability‐related background variables and performance for assigning students to suitable items. Furthermore, we investigated whether uncertainty about item difficulty could impair the assembling of efficient designs. The results indicated that targeted multistage calibration designs were more efficient than ordinary targeted designs under optimal conditions. Limited knowledge about item difficulty reduced the efficiency of one of the two investigated targeted multistage calibration designs, whereas targeted designs were more robust.     

The functional use of a mathematical sign

The question of how a mathematics student at university-level makes sense of a new mathematical sign, presented to her or him in the form of a definition, is a fundamental problem in mathematics education. Using an analogy with Vygotsky's theory (1986, 1994) of how a child learns a new word, I argue that a learner uses a new mathematical sign both as an object with which to communicate (like a word is used) and as an object on which to focus and to organise her or his mathematical ideas (again as a word is used) even before she or he fully comprehends the meaning of this sign. Through this sign usage, I claim that the mathematical concept evolves for that learner so that it eventually has personal meaning, like the meaning of a new word does for a child; furthermore, because the usage is socially regulated, I claim that the concept evolves for the learner so that its usage concurs with its usage in the mathematical community. In line with Vygotsky, I call this usage of the mathematical sign before mature understanding, ‘functional use’. I demonstrate ‘functional use’ of signs (manipulations, imitations, template-matching and associations) through an analysis of an interview in which a mathematics university student engages with a ‘new’ mathematical sign, the improper integral, using pedagogically designed tasks and a standard Calculus textbook as resources.     

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.     

Emergent literacy and reading acquisition: a longitudinal study from kindergarten to primary school

European Journal of Psychology of Education - This study explores the predictivity of an emergent literacy model on the acquisition of reading in primary school in a language with a transparent...