Scaffolding the design of accessible eLearning content: a user-centered approach and cognitive perspective

There exist various guidelines for facilitating the design, preparation, and deployment of accessible eLearning applications and contents. However, such guidelines prevalently address accessibility in a rather technical sense, without giving sufficient consideration to the cognitive aspects and issues related to the use of eLearning materials by learners with disabilities. In this paper we describe how a user-centered design process was applied to develop a method and set of guidelines for didactical experts to scaffold their creation of accessible eLearning content, based on a more sound approach to accessibility. The paper also discusses possible design solutions for tools supporting eLearning content authors in the adoption and application of the proposed approach.     

Stimulus-driven attentional capture: An empirical comparison of display-size and distance methods

Four experiments examined attentional capture by colour as assessed by two different investigative methods. Subjects performed a visual search task for a vertical-target line embedded among tilted-distractor lines, presented inside 4, 8, or 12 coloured discs. Interestingly, when the colour singleton was task irrelevant, and data were analysed by means of the display-size method combined with the zero-slope criterion, no evidence for attentional capture by colour was found. However, when data were analysed by means of the distance method, which consists of monitoring the spatial relationship between the target and the singleton, results showed that the target was found faster and/or more accurately when it was inside the singleton than when it was in a nonsingleton location. This provided evidence for a stimulus-driven attentional capture. In addition, the application of signal detection methodology showed that attentional capture, as revealed by the distance method, resulted from a perceptual modulation at the singleton location, rather than from a criterion shift. We conclude that, at least with the kind of stimuli used here, the display-size method combined with the zero-slope criterion is less than ideal for investigating how static discontinuities can affect the automatic deployment of visual attention.     

A conditioned weight illusion: Reafference learning without a correlation store

Each of 20 female college students repeatedly judged the weight of a heavy metal cylinder dropped repeatedly (180 times) into her waiting hand. The cylinder came to appear lighter to her when the release of the cylinder was accompanied by the onset of an indicator lamp than when it was not, but only providing the onset of the lamp preceded the release of the cylinder by a half second rather than being simultaneous with it. This conditional illusion has implications for von Holst and Mittelstaedt’s well-known thesis that every neural efference leaves an efference copy or corollary discharge of itself in the nervous system to be compared with concurrent neural reafference. Apparently some types of conditioned-efference leave no copies, and objects lifted in part by such unregistered efforts appear lightened accordingly. The illusion illustrates a form of reafference learning that need involve no correlation store (Held, 1961).     

Subdirectly Irreducible Modal Algebras and Initial Frames

The duality between general frames and modal algebras allows to transfer a problem about the relational (Kripke) semantics into algebraic terms, and conversely. We here deal with the conjecture: the modal algebra A is subdirectly irreducible (s.i.) if and only if the dual frame A* is generated. We show that it is false in general, and that it becomes true under some mild assumptions, which include the finite case and the case of K4. We also prove that a Kripke frame F is generated if and only if the dual algebra F* is s.i. The technical result is that A is s.i. when the set of points which generate the dual frame A* is not of zero measure.     

An effective fixed-point theorem in intuitionistic diagonalizable algebras

Summary Within the technical frame supplied by the algebraic variety of diagonalizable algebras, defined by R. Magari in [2], we prove the following:LetT be any first-order theory with a predicate Pr satisfying the canonical derivability conditions, including Löb's property. Then any formula inT built up from the propositional variables q, p₁, ..., p_n, using logical connectives and the predicate Pr, has the same fixed-points relative to q (that is, formulas (p₁ ..., p_n) for which for all p₁, ..., p_n T((p₁, ..., p_n), p₁, ..., p_n) (p₁, ..., p_n)) of a formula ^* of the same kind, obtained from in an effective way.Moreover, such ^* is provably equivalent to the formula obtained from substituting with ^* itself all the occurrences of q which are under Pr. In the particular case where q is always under Pr in , ^* is the unique (up to provable equivalence) fixedpoint of .Since this result is proved only assumingPr to be canonical, it can be deduced that Löb's property is, in a sense, equivalent to Gödel's diagonalization lemma.All the results are proved more generally in the intuitionistic case.The algebraization of the theories which express Theor, IXAllatum est die 19 Decembris 1975     

The Effect of Perceived Challenges and Skills on the Quality of Subjective Experience

ABSTRACT This article investigates the effects that perceived challenges and skills in activities have on the quality of everyday life experience. Based on flow theory it was predicted that quality of daily experience would depend on the challenge experienced and skill required in specific situations, as well as on the balance between challenge and skill. The Experience Sampling Method (ESM) was used on a sample of 208 talented adolescents to measure daily variations in four dimensions of experience (concentration, wish to do the activity, involvement, and happiness) in four contexts (in school, with relatives, with friends, and in solitude). The four dimensions of experience were regressed on the predictors challenges, skills, and their absolute difference expressing the balance/imbalance of challenges and skills. Hierarchical linear modeling, explained in detail herein, was conducted on a 1-week sample of experiences. Findings confirm the prediction of flow theory that the balance of challenges and skills has a positive and independent effect on the quality of experience. Yet some differences of parameter estimates were found between dimensions of experience and between social contexts. These heterogeneities call for a further improvement of the flow model.     

Medical diagnostic reasoning: Epistemological modeling as a strategy for design of computer-based consultation programs

The complexity of cognitive emulation of human diagnostic reasoning is the major challenge in the implementation of computer-based programs for diagnostic advice in medicine. We here present an epistemological model of diagnosis with the ultimate goal of defining a high-level language for cognitive and computational primitives. The diagnostic task proceeds through three different phases: hypotheses generation, hypotheses testing and hypotheses closure. Hypotheses generation has the inferential form of abduction (from findings to hypotheses) constrained under the criterion of plausibility. Hypotheses testing is achieved by a deductive inference (from generated hypotheses to expected findings), followed by an eliminative induction, constrained under the criterion of covering, which matches expected findings against patient's findings to select the best explanation. Hypotheses closure is a deductive-inductive type of inference very similar to the inferences operating in hypotheses testing. In this case induction matches the consequences of the generated hypotheses against the patient's characteristics or preferences under the criterion of utility. By using the language exploited in this epistemological model, it is possible to describe the cognitive tasks underlying the most influential knowledge-based diagnostic systems.     

Advancing Creativity Theory and Research: A Socio-cultural Manifesto

This manifesto, discussed by 20 scholars, representing diverse lines of creativity research, marks a conceptual shift within the field. Socio-cultural approaches have made substantial contributions to the concept of creativity over recent decades and today can provide a set of propositions to guide our understanding of past research and to generate new directions of inquiry and practice. These propositions are urgently needed in response to the transition from the Information Society to the Post-Information Society. Through the propositions outlined here, we aim to build common ground and invite the community of creativity researchers and practitioners to reflect up, study, and cultivate creativity as a socio-cultural phenomenon.     

The attribute priming effect in patients with Alzheimer's disease

Experiments with semantic priming (SP) paradigms have documented early hypopriming in patients with AD when concepts are used as primes and attribute concept features as targets, suggesting that concept attributes are vulnerable to damage very early in the disease course. The aims of this study were to confirm early priming reduction in the attribute condition in patients with AD and to determine which of several semantic indexes (such as the level of distinctiveness, correlation or feature dominance of concept features) best predicts the priming effect size in AD. We administered an SP attribute condition paradigm to 20 mildly demented patients with AD and to 10 NCs. We used concept–attribute pairs for which normative data of semantic indexes relative to both concept primes (i.e., number, type, mean level of dominance, distinctiveness and correlation of features constituting the concepts) and target features (i.e., level of feature dominance, correlation and distinctiveness) were available. Results showed that compared to NCs, the AD group obtained very reduced priming facilitation. Furthermore, the item regression analyses showed that the priming decrement in the AD group was predicted by the feature dominance of the target in the related pairs; that is, the lower the target feature dominance, the lower the priming effect elicited. These results confirmed hypopriming in the attribute condition from the very early phase of AD and support the view that attributes which are more salient for the identification of a given concept are also those most resistant to semantic memory degradation in AD pathology.