Composing your Compositions of Variability Models

International audienceModeling and managing variability is a key activity in a growing number of software engineering contexts. Support for composing variability models is arising in many engineering scenarios, for instance, when several subsystems or modeling artifacts, each coming with their own variability and possibly developed by different stakeholders, should be combined together. In this paper, we consider the problem of composing feature models (FMs), a widely used formalism for representing and reasoning about a set of variability choices. We show that several composition operators can actually be defined, depending on both matching/merging strategies and semantic properties expected in the composed FM. We present four alternative forms and their implementations. We discuss their relative trade-offs w.r.t. reasoning, customizability, traceability, composability and quality of the resulting feature diagram. We summarize these findings in a reading grid which is validated by revisiting some relevant existing works. Our contribution should assist developers in choosing and implementing the right composition operators

Informing Writing: The Benefits of Formative Assessment

Examines whether classroom-based formative writing assessment - designed to provide students with feedback and modified instruction as needed - improves student writing and how teachers can improve such assessment. Suggests best practices

Widespread abiotic methane in chromitites

Recurring discoveries of abiotic methane in gas seeps and springs in ophiolites and peridotite massifs worldwide raised the question of where, in which rocks, methane was generated. Answers will impact the theories on life origin related to serpentinization of ultramafic rocks, and the origin of methane on rocky planets. Here we document, through molecular and isotopic analyses of gas liberated by rock crushing, that among the several mafic and ultramafic rocks composing classic ophiolites in Greece, i.e., serpentinite, peridotite, chromitite, gabbro, rodingite and basalt, only chromitites, characterized by high concentrations of chromium and ruthenium, host considerable amounts of 13C-enriched methane, hydrogen and heavier hydrocarbons with inverse isotopic trend, which is typical of abiotic gas origin. Raman analyses are consistent with methane being occluded in widespread microfractures and porous serpentine- or chlorite-filled veins. Chromium and ruthenium may be key metal catalysts for methane production via Sabatier reaction. Chromitites may represent source rocks of abiotic methane on Earth and, potentially, on Mars

Children with Dyslexia: Spelling as a Constraint on Writing Development

Background. Developmental dyslexia is characterised as a specific learning difficulty with written language: namely, reading and spelling. To date, little research has been conducted to examine the role of spelling when writing and, in particular, in the writing of young children with dyslexia. This is surprising when considering that spelling is an active process used when transcribing written text. Thus, this thesis aimed to investigate the impact of spelling ability in four areas: the quality of the written compositions produced, spelling error analyses, vocabulary choice when writing, and handwriting execution. Method. Thirty-one children with dyslexia (15 boys, 16 girls; 9 years) were compared to two typically developing groups: the first matched by age and the second by spelling-ability. Participants completed tasks that assessed cognitive ability, spelling, reading, working memory, narrative writing, vocabulary level, motor skill, and handwriting performance. A digital writing tablet was used to record and identify the temporal characteristics of handwriting. Results. Children with dyslexia scored significantly below their peers for written text quality, wrote less overall, and demonstrated a higher number of phonetically and orthographically inaccurate spelling errors. Limited vocabulary choices and a more disfluent handwriting profile were characteristics of the writing by children with dyslexia. These children with dyslexia did not have motor difficulties and demonstrated that handwriting execution speed was in fact similar to their peers. Rather, children with dyslexia paused more frequently before misspellings and within-words, a similar pattern to the younger spelling-ability matches. Spelling ability was found to predict a large proportion of variance in handwriting speed, written vocabulary choice, and the quality of the written text produced by children with dyslexia. Conclusions. A new model of the interacting writing processes was proposed, emphasising the importance of acquiring strong foundations in proficient spelling for writing to progress. The proposed model relates to atypical and typical development. The findings are related to theories of dyslexia and avenues for future research are discussed in relation to expanding the new writing model

Critical Team Composition Issues for Long-Distance and Long-Duration Space Exploration: A Literature Review, an Operational Assessment, and Recommendations for Practice and Research

Prevailing team effectiveness models suggest that teams are best positioned for success when certain enabling conditions are in place (Hackman, 1987; Hackman, 2012; Mathieu, Maynard, Rapp, & Gilson, 2008; Wageman, Hackman, & Lehman, 2005). Team composition, or the configuration of member attributes, is an enabling structure key to fostering competent teamwork (Hackman, 2002; Wageman et al., 2005). A vast body of research supports the importance of team composition in team design (Bell, 2007). For example, team composition is empirically linked to outcomes such as cooperation (Eby & Dobbins, 1997), social integration (Harrison, Price, Gavin, & Florey, 2002), shared cognition (Fisher, Bell, Dierdorff, & Belohlav, 2012), information sharing (Randall, Resick, & DeChurch, 2011), adaptability (LePine, 2005), and team performance (e.g., Bell, 2007). As such, NASA has identified team composition as a potentially powerful means for mitigating the risk of performance decrements due to inadequate crew cooperation, coordination, communication, and psychosocial adaptation in future space exploration missions. Much of what is known about effective team composition is drawn from research conducted in conventional workplaces (e.g., corporate offices, production plants). Quantitative reviews of the team composition literature (e.g., Bell, 2007; Bell, Villado, Lukasik, Belau, & Briggs, 2011) are based primarily on traditional teams. Less is known about how composition affects teams operating in extreme environments such as those that will be experienced by crews of future space exploration missions. For example, long-distance and long-duration space exploration (LDSE) crews are expected to live and work in isolated and confined environments (ICEs) for up to 30 months. Crews will also experience communication time delays from mission control, which will require crews to work more autonomously (see Appendix A for more detailed information regarding the LDSE context). Given the unique context within which LDSE crews will operate, NASA identified both a gap in knowledge related to the effective composition of autonomous, LDSE crews, and the need to identify psychological and psychosocial factors, measures, and combinations thereof that can be used to compose highly effective crews (Team Gap 8). As an initial step to address Team Gap 8, we conducted a focused literature review and operational assessment related to team composition issues for LDSE. The objectives of our research were to: (1) identify critical team composition issues and their effects on team functioning in LDSE-analogous environments with a focus on key composition factors that will most likely have the strongest influence on team performance and well-being, and 1 Astronaut diary entry in regards to group interaction aboard the ISS (p.22; Stuster, 2010) 2 (2) identify and evaluate methods used to compose teams with a focus on methods used in analogous environments. The remainder of the report includes the following components: (a) literature review methodology, (b) review of team composition theory and research, (c) methods for composing teams, (d) operational assessment results, and (e) recommendations

Extended methods of notation in Josh Levine's Les yeux ouverts and Daniel Tacke's Einsamkeit

Master's Project (M.Mu.) University of Alaska Fairbanks, 201

Multimodal and print composition : an examination of instructors and students transferring rhetorical knowledge in first-year composition.

This dissertation is a case-study of three instructors and five of their students in first-year composition who were making the transition from print to multimodal composition. This study examines the similarities and differences in the ways instructors and students talk about print and multimodal compositions and if the vocabulary they use to talk about each transfers or if they need a new vocabulary to discuss the multimodal compositions. The results of this study seem to indicate that language common to both print and multimodal composition, such as having a clear assertion, was transferrable both between the print and multimodal projects and between the instructors and their students. This study also indicates that multimodal composition seems to be a good place to focus on composing for a broad audience. Unlike the print text where students had trouble seeing an audience other than the instructor, all of the students interviewed were very clear about the ways their assertions or their presentation choices in the multimodal compositions would affect their audience. Transfer of concepts was a concern with issues of presentation because the instructors and their students had no common vocabulary about the presentation and design issues which surround multimodal composition. For instructors, presentations which did not take advantage of the affordances became flat or digital arguments with too much text were heavy. The students had a more is better approach which relied on their intuition to guide them in making presentation decisions. The lack of a language to talk about presentation issues combined with the time the instructors perceived that students spent on the multimodal compositions led to evaluation anxiety for the instructors. All three instructors expressed anxiety about multimodal evaluation that was not present in their evaluation of the print texts. This study both suggests that it is possible to transfer from the rhetorical vocabulary compositionists use to discuss print to multimodal compositions and that we need to work harder to increase these points of transfer

Domain Specific Languages for Managing Feature Models: Advances and Challenges

International audienceManaging multiple and complex feature models is a tedious and error-prone activity in software product line engineering. Despite many advances in formal methods and analysis techniques, the supporting tools and APIs are not easily usable together, nor unified. In this paper, we report on the development and evolution of the Familiar Domain-Specific Language (DSL). Its toolset is dedicated to the large scale management of feature models through a good support for separating concerns, composing feature models and scripting manipulations. We overview various applications of Familiar and discuss both advantages and identified drawbacks. We then devise salient challenges to improve such DSL support in the near future