Teaching human- computer interaction in context: an illustrative lesson on windows

To date, courses on human-computer interaction (HCI) at different institutions are very different in their content and form. They are often criticized as too practical or too theoretical, too technical or too behavioural. This paper proposes and illustrates an approach for introducing HCI that blends psychology, the work context and practical techniques. It is based on the goal of attaining a fit between user, task and technology and combines two themes that organize the material. First, user activity is examined at four levels of interaction: task, semantic, syntactic and lexical. The discussion of any specific topic, such as the use of graphics, is conducted in the task context. In this paper the context is managerial and office work, which include tasks such as making decisions and communicating. Second, user activity is analysed as a function of user characteristics such as memory, attention, comprehension and affect. The approach is demonstrated with a lesson on the design of windows.     

Restraining the Golem: Boosting performance by changing the interpretation of low scores.

The Golem effect is the negative impact on subordinates' performance that results from low leader expectations toward them. The effects of low expectations were studied experimentally by preventing the natural formation of low expectations toward individuals who had obtained low test scores in some units and by refraining from doing so in other units. Randomly selected squad leaders (n?=?17) were led to believe that low scores on a physical fitness test were not indicative of subordinates' ineptitude. Control squad leaders (n?=?17) were not told how to interpret the test scores. Two posttests showed that low-scoring personnel in the experimental squads improved more than those in the control squads, maintained the difference, rated their squad leaders more favorably, and were more satisfied, but they were not significantly more anxious. The potential for low scores on valid tests to produce unintended Golem effects is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pygmalion goes to boot camp: Expectancy, leadership, and trainee performance.

Tested the applicability of the Pygmalion effect to adult military trainees and examined the effects of expectancy on instructor leadership. 105 male Ss were matched on aptitude and randomly assigned to high, regular, and unspecified instructor-expectancy conditions. The Pygmalion hypothesis was confirmed. Ss with instructors who had been induced to expect better performance scored significantly higher on objective achievement tests, exhibited more positive attitudes, and perceived more positive leadership behavior. Instructor expectancy explained 73% of the variance in performance, 66% in attitudes, and 28% in leadership. The causal interplay between expectancy, leadership, and performance, and the notion of applying the Pygmalion effect by deliberately raising supervisors' expectations through "expectancy training" are discussed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Design of a Piezoelectric Heart Assist Device

A piezoelectric heart assist device was designed, and preliminary tests were performed in vitro and in vivo. The device has the advantages of simple construction, low power consumption (approximately one watt), electrical rather than pneumatic drive, and noiseless operation. The device consists of piezoelectric bender elements forming two cantilevers. A unique feature of the device is that two tungsten alloy masses, 0.44 kg each, were added to the free ends of the cantilevers to reduce the resonant frequency to 2.5 Hz. The driving voltage was a 320 V peak-to-peak square wave synchronized with a paced heartbeat.     

Compositional study and properties characterisation of alkaline earth feldspar glasses and glass-ceramics

Fields in which metastable crystallisation of feldspars may occur as a result of heterogeneous nucleation were defined at 1000° C for the systems BaO-Al₂O₃-SiO₂, SrO-Al₂O₃-SiO₂, and CaO-Al₂O₃-SiO₂. The metastable fields of the above barium and calcium systems differ considerably from the respective primary liquidus fields of celsian and anorthite with the tendency for the stoichiometric compositions to be situated at the centre of the metastable region.Various physical and dielectric properties of the glasses and glass-ceramics of the three systems are presented and compared. High linear thermal expansion, high electrical resistivity, and low loss tangent and dielectric constant characterise these glass-ceramics. One of them (No. 2, table I) has, in addition, high heat resistance and translucency at high temperatures.     

Heterogeneous nucleation of alkaline earth feldspars in glasses

Though suitable conditions of structural geometry favouring epitaxy were demonstrated, yet it was observed that epitaxy was not a dominant and, possibly, not even an important factor in the nucleation processes studied. Indeed, the mere presence of close structural geometrical fit between the catalyst and the nucleus does not necessarily lead to epitaxy. Other factors such as the concentration of the nucleating agent in the glass and variations in the chemical composition of the glass, and their effects on the nucleation are discussed. Also the effect of the feldspar structure on the kinetic barrier for its nucleation, and several specific liquid phase separation phenomena, are evaluated.     

Mapping Knowledge about Product Lifecycle Engineering for Ontology Construction via Object-Process Methodology

Knowledge mapping is a first and mandatory step in ontology definition. This paper considers the lifecycle of products and systems, and discusses the creation of a knowledge-based ontology. With respect to the life cycle of products and systems, knowledge refers to the processes involved in their creation (design manufacturing and assembly), use and maintenance, and end of life (EOL). Hence, this knowledge should consider what a product is comprised of (its structure), how it operates (its dynamics), and how it interacts with the environment. A clearly defined and consistent mapping of knowledge regarding structure, operation and interaction is necessary to construct an effective and useful ontology. Yet, in order to obtain the required knowledge and to organize it in a consistent and useful form, an appropriate ontology must be used. An interactive, iterative and consistent method is needed to cope with this complex and circular problem. In this paper, the Object-Process Methodology (OPM) approach is considered, along with OPCAT [1], a tool for OPM-based knowledge modeling. OPM is a systems-modeling approach that represents knowledge about systems concurrently and bi-modally through graphics (a set of Object-Process Diagrams, OPDs) and text (Object-Process Language, OPL, a subset of English), yielding a single, unified and consistent view. In this paper we propose a foundational modeling and ontology construction approach for a generic product that incorporates hardware and software components. The ontology can serve as a basis for a knowledge model to cover the entire product lifecycle, from inception to EOL, and can be applied in the VRL-KCiP Network of Excellence.     

Object-Oriented Analysis: Is It Just Theory?

Academic researchers and practitioners frequently describe a situation in which the object-oriented (OO) approach strongly supports the design and coding phases of software development but only weakly supports the analysis phase. Such observations conflict with impressions imparted by textbooks and training programs. This article examines whether object oriented analysis (OOA) theory has been deployed in practice (with or without support of computer-aided software engineering tools) or whether it exists only in theory. This study explores 54 projects, diverse in scope and topic, all of which were implemented using object-oriented tools. The study shows that practitioners haven't widely adopted the theoretically popular OOA and suggests a cost-benefit perspective, arguing that OOA fails to attract practitioners because of a low ratio of costs to benefits relative to other methodologies. In particular, practitioners perceive the cost of system modeling using OOA methodologies and UML diagrams as high relative to its benefits. The authors present of recommendations to reduce costs and increase benefits in OOA.     

A Theory of Hierarchical Consequence and Conditionals

We introduce A{\mathcal{A}} -ranked preferential structures and combine them with an accessibility relation. A{\mathcal{A}} -ranked preferential structures are intermediate between simple preferential structures and ranked structures. The additional accessibility relation allows us to consider only parts of the overall A{\mathcal{A}} -ranked structure. This framework allows us to formalize contrary to duty obligations, and other pictures where we have a hierarchy of situations, and maybe not all are accessible to all possible worlds. Representation results are proved.