Modern software systems are becoming increasingly integrated and are required to operate over organizational boundaries through networks. The development of such distributed software systems has been shaped by the orthogonal trends of service-orientation and process-awareness. These trends put an emphasis on technological neutrality, loose coupling, independence from the execution platform, and location transparency. Execution platforms supporting these trends provide context and cross-cutting functionality to applications and are referred to as engines.
Applications and engines interface via language standards. The engine implements a standard. If an application is implemented in conformance to this standard, it can be executed on the engine. A primary motivation for the usage of standards is the portability of applications. Portability, the ability to move software among different execution platforms without the necessity for full or partial reengineering, protects from vendor lock-in and enables application migration to newer engines.
The arrival of cloud computing has made it easy to provision new and scalable execution platforms. To enable easy platform changes, existing international standards for implementing service-oriented and process-aware software name the portability of standardized artifacts as an important goal. Moreover, they provide platform-independent serialization formats that enable the portable implementation of applications. Nevertheless, practice shows that service-oriented and process-aware applications today are limited with respect to their portability. The reason for this is that engines rarely implement a complete standard, but leave out parts or differ in the interpretation of the standard. As a consequence, even applications that claim to be portable by conforming to a standard might not be so.
This thesis contributes to the development of portable service-oriented and process-aware software in two ways: Firstly, it provides evidence for the existence of portability issues and the insufficiency of standards for guaranteeing software portability. Secondly, it derives and validates a novel measurement framework for quantifying portability. We present a methodology for benchmarking the conformance of engines to a language standard and implement it in a fully automated benchmarking tool. Several test suites of conformance tests for two different languages, the Web Services Business Process Execution Language 2.0 and the Business Process Model and Notation 2.0, allow to uncover a variety of standard conformance issues in existing engines. This provides evidence that the standard-based portability of applications is a real issue. Based on these results, this thesis derives a measurement framework for portability. The framework is aligned to the ISO/IEC Systems and software Quality Requirements and Evaluation method, the recent revision of the renowned ISO/IEC software quality model and measurement methodology. This quality model separates the software quality characteristic of portability into the subcharacteristics of installability, adaptability, and replaceability. Each of these characteristics forms one part of the measurement framework. This thesis targets each characteristic with a separate analysis, metrics derivation, evaluation, and validation. We discuss existing metrics from the body of literature and derive new extensions speciffically tailored to the evaluation of service-oriented and process-aware software. Proposed metrics are defined formally and validated theoretically using an informal and a formal validation framework. Furthermore, the computation of the metrics has been prototypically implemented. This implementation is used to evaluate metrics performance in experiments based on large scale software libraries obtained from public open source software repositories.
In summary, this thesis provides evidence that contemporary standards and their implementations are not sufficient for enabling the portability of process-aware and service-oriented applications. Furthermore, it proposes, validates, and practically evaluates a framework for measuring portability.
Over the last decades, large-scale assessments focusing on skills and knowledge of individuals have expanded significantly in order to obtain information about conditions for and consequences of competence acquisition. To provide valid and accurate scores of the subjects under investigation, it is necessary to thoroughly check the psychometric properties of the competence instruments that are administered and to choose appropriate scaling models for the competence data. In this thesis, various challenges in modeling competence data were addressed that arose from different recently developed competence tests in large-scale assessments. The different tests posed specific demands on the scaling of the data such as dealing with multidimensionality, incorporating different response formats, or linking competence scores. By investigating these challenges associated with each of the competence tests, the aim of the thesis was to draw implications for the specification of the scaling models for the competence data.
First, a new metacognitive knowledge test for early elementary school children was investigated. As earlier findings on metacognitive knowledge in secondary school pointed to empirically distinguishable components of metacognitive knowledge, especially the dimensionality of the newly developed test was studied. Therefore, uni- and multidimensional models were applied to the competence data and their model fit was compared. By applying multidimensional latent-change models, the homogeneity of change was observed as further indicator for dimensionality. Overall, the new test instrument exhibited good psychometric properties including fairness of the items for various subgroups. In accordance with previous studies in other age groups the results indicated a multidimensional structure of the newly developed test instrument. In the discussion, theoretical as well as empirical arguments were compiled that should be considered for the choice of a uni- or a multidimensional model for the metacognitive knowledge data.
The next objective in the thesis was to study a series of reading competence tests intended to measure the same latent trait across a large age span. The different reading competence tests, developed in a longitudinal large-scale study, were based on the same conceptual framework and were administered from fifth grade to adulthood. We specifically investigated whether the test scores were comparable across such a large age span enabling to interpret change across time. The analyses on the reading competence tests showed that the coherence of measurement could not fully be assured across the wide age range. The application of strict linking models allowing for the interpretation of developmental progress seemed to be justified within secondary school, but not between secondary school and adulthood.
The last purpose in the thesis was to find out how to adequately incorporate different response formats in a scaling model. Therefore, multiple choice (MC) and complex multiple choice (CMC) items were regarded as they are most frequently used in large-scale assessments. Specifically, we explored whether the two response formats form distinct empirical dimensions and which a priori scoring schemes for the two response formats appropriately model the competence data. The results demonstrated that the response formats built a unidimensional measure across domains, studies, and age cohorts justifying to use a unidimensional scale score. A differentiated scoring of the CMC items yielded a better discrimination between persons and was, thus, preferred. The a priori weighting scheme of giving each subtask of a CMC item half the weight of a MC item described the empirical competence data well.
This dissertation derives new ways and methods on how to integrate and bind developers in Free Libre Open Source Software (FLOSS) projects. It examines how sustainable commitment of new contributors can be identified at an early stage, how developers’ geographic dispersion affects their collaboration productivity, if the presence of reputable developers increases teamwork productivity and if mentoring is an appropriate means to bind developers in FLOSS projects. To address these research questions, the thesis builds on established theories and concepts from organizational and social science such as Person-Job (P-J) and Person-Team (P-T) fit, the social practice view and self-determination theory. The results of the performed empirical evaluations suggest that: (i) the derived criteria for P-J and P-T fit are suitable to identify sustained commitment early on, (ii) developers’ offline relationships determine if their spatial and cultural distance becomes a gain or a burden for their collaboration, (iii) the presence of reputable developers increases productivity in FLOSS projects only marginally, (iv) mentoring is an appropriate means to bind developers in FLOSS projects
In the last decade, several efforts have been made to improve teaching and intervening practice in preschool classrooms by means of professional development programs (Mar-tinez-Beck & Zaslow, 2006; OECD, 2012). In-service professional development for pre-school teachers varies widely with respect to amount, duration, delivery format (traditional workshop and course vs. modern approaches such as coaching, mentoring, blended learning) and content (Oberhuemer, 2012; 2013). In general, it is assumed that in-service training enhances teachers’ knowledge, skills, and classroom practice. Improved teaching practice enhances student achievement. The connection seems intuitive, but empirical demonstration is difficult. Therefore, the purpose of this investigation was to conduct a research synthesis on the results of in-service professional development effects and to draw conclusions about the findings on potential effect modifiers into an integrated frame-work.
Systematic review procedures and meta-analytic techniques were used to estimate the effectiveness of in-service programs. The review consists of experimental studies (RCT, CRT, quasi-experimental and non-experimental studies) that have evaluated the impact of professional development for teachers working in center-based care on quality ratings and child development. Electronic searches (ERIC, PsycINFO, ProQuest, FIS, and WISO) and hand searches in renowned journals from 1970 to 2011 produced 1,162 hits. Two inde-pendent coders extracted statistical information from the full texts and screened the litera-ture on the quality of the studies, in-service characteristics, and training transfer factors. A randomized multi-level procedure was used to aggregate the summary impact, where effect sizes were nested under treatment.
Overall, 36 studies provided sufficient data to conduct a meta-analysis of in-service train-ing effects on quality ratings. The aggregation of findings revealed a medium summary effect g’ = 0.64 (SE = 0.071). Alongside methodological variables, the size of the effect was statistically moderated by training intensity and format. In-service programs with 45 to 60 hours of training and programs that used coaching as their sole format were the most effective.
The impact of professional development programs on the language and literacy abilities of young children have been investigated in 48 studies. The summary effect was small
g’ = 0.38 (SE = 0.045). Differential impacts and variations in the size of the effects were found for different outcome domains. Effect sizes were moderated by methodological as-pects, training design and intensity. Programs with 15 to 30 hours of training were the most effective in fostering language and literacy skills. Approaches that used mixed delivery types, in particular the combination of workshop and course had a larger impact.
For the meta-analysis of in-service training effects on social skills and reduced problem behavior, 13 studies provided sufficient data. A small summary effect was found: g’ = 0.45 (SE = 0.074). However, differential effects emerged for different outcome domains. In particular, larger effects were found for the promotion of social skills than for the reduction of problem behavior. Alongside methodological variables, training programs with a duration of 9 months or short-term programs with less than 30 hours of training were significantly more effective.
To investigate the link between in-service professional development, quality improvements and child development, 9 studies were found that provide data on both quality ratings and child development. In-service training effects on student achievement could be significantly predicted by quality improvements that occurred during training. More than
53 % of the variance in effects on child development was explained by the quality ratings which emerged as a result of in-service professional training.
In addition to the meta-analyses, narrative reviews identified some features of highly ef-fective in-service programs with a calculated effect of g > 0.80. Narrative analysis indicat-ed that a narrow content focus and educational principles matter. In particular, effective programs provided opportunities for active learning, guidance and feedback as well as performance-based assignments during training and between training sessions. Further, the trainers of highly effective programs were either the authors of the program or had a specific pretraining/license for the program.
Several effect modifiers were tested. In the majority of cases, the effects were influenced by methodological issues (e.g., pretest differences, reliability of scales or informants) and training intensity in hours. However, the results for training delivery variables were incon-sistent. Clear conclusions on other characteristics cannot be made from the meta-regression, because the findings were either inconsistent or missing information in primary studies hindered the investigation.
In summary, there are some beneficial programs and the synthesis of research findings suggests that most of the in-service training has positive effects on the quality of early education and child development. The results demonstrate that quality improvements are a key mechanism to enhance student achievement. Some conclusions for achieving highly professional development with regards to duration and intensity, educational principles and trainers can be drawn. Recommendations for further research include high quality research designs (e.g., equivalence of groups, reliable scales, etc.) and data collection on confounding and contextual variables. Nevertheless, some questions remain in analyzing in-service training effects. In particular, more research and primary studies are needed to investigate the heterogeneity of the results and the moderating role of implementation processes and program fidelity.
This dissertation presents research projects which investigated dynamics in the perception and appreciation of ambiguous and indeterminate art. It examines how semantical instability in art can induce pleasure in the perceiver although defying an easy consumption. The idea pursued within this thesis is that insights gained during an elaboration of such objects lead to an increase in appreciation (Aesthetic Aha effect, Muth & Carbon, 2013)—the creation of meaning itself being rewarding. The comprised research projects examine such dynamics in perception and appreciation of visual artworks which are semantically instable. A crucial quality of these objects might be that they confront the perceiver with semantical instability as well as opportunity for insight: for instance, we like Cubist artworks more the better we are able to discern identifiable objects in them—still they never dissolve into an easy recognizable interpretation (Muth, Pepperell, & Carbon, 2013a). Also the solvability of ambiguity in another set of visual artworks did not have positive effects on liking, interest, and affect. Instead, the strength of insights gained during their elaboration predicted appreciation positively (Muth, Hesslinger, & Carbon, 2015). In line with the Aesthetic Aha effect (Muth & Carbon, 2013) also the sudden emergence of Gestalt within indeterminate artistic movies elicited an increase in liking. Interest—in contrast –already increased prior to these moments of insight (Muth, Raab, & Carbon, 2015). The presented findings highlight that art perception does not equal a kind of problem solving process in which semantical instability needs to be resolved for the artwork to appeal. Instead appreciation might benefit from rewarding insights into the instable.
The main objective of this thesis is to bridge the gap between modeling method experts on the one side and tool developers on the other. More precisely, the focus is on the specification of requirements for multi-view modeling tools. In this regard, the thesis introduces a methodological approach that supports the specification of conceptual designs for multi-view modeling tools in a stepwise manner: the MuVieMoT approach. MuVieMoT utilizes generic multi-view modeling concepts and the model-driven engineering paradigm to establish an overarching specification of multi-view modeling tools with an emphasis on consistency requirements. The approach builds on and extends the theoretical foundation of metamodeling and multi-view modeling: generic multi-view modeling concepts, integrated multi-view modeling approaches, and possibilities for formalized modeling method specifications. Applicability and utility of MuVieMoT are evaluated using an illustrative scenario, therefore specifying a conceptual design for a multi-view modeling tool for the Semantic Object Model enterprise modeling method. The thesis moreover introduces the MuVieMoT modeling environment, enabling the efficient application of the approach as well as the model-driven development of initial multi-view modeling tools based on the conceptual models created with MuVieMoT. Consequently, the approach fosters an intersubjective and unambiguous understanding of the tool requirements between method experts and tool developers.
An airport is the gateway which facilitates access to air transport. As a reaction to very diverse attacks on the air transport system during the last decades a broad range of security measures has been introduced to mitigate possible threats. The challenge to provide a trouble free experience for the passenger and, at the same time, to oper-ate more efficiently calls for a proactive approach. This requires the definition of future requirements that allow an adaptation of the security system. When dealing with uncertainty that future-oriented decisions inevitably display, it is important to gain as much knowledge as possible about a system’s general structure. The approach described in this paper systematically documents elements and relationships of the airport security system. It consists of threat scenario elements as well as security measures. The development of a software tool, the so-called Scenario Builder, is described and its application for the identification of possible future threats ex-plained. The presented approach offers intuitive access to the underlying structure of the airport security system. It provides decision makers with a possibility to interact with the system and anticipate effects of threat development, thereby enabling robust, future-oriented decisions.
This PhD thesis investigates the relationship between corporate IT capability and institutional investors from two different perspectives. From the first perspective, institutional investors influence companies in their strategies and objectives. From the second, IT capability has considerable firm-internal implications that increase future prospects and firm value, which in turn attracts certain investors. The empirical results illustrate significant differences in ownership structure for firms characterized by superior IT capability. Looking deeper into this phenomenon indicates that the development of a firm’s IT capability is related to subsequent changes in the ownership structure towards more long-term oriented institutional shareholders and vice versa. This dissertation contributes to the understanding of the firm-external influences of institutional investors as well as the capital market implications of firms’ IT capability.
The eponymous heroes of "Strange Case of Dr Jekyll and Mr Hyde", "The Picture of Dorian Gray" and "Dracula" are known to most through the medium of film. These novels were adapted early on in the history of the medium and have been revisited by film makers countless times. This book asks why they had such a lasting resonance in film. It claims that the monsters featured in these novels, which were written at the advent of cinematography, differ from previous Gothic leads: Jekyll/Hyde, Dorian Gray and Dracula were born from a sense of unease with the photographic image at a time when it began to move. They embody fears triggered by new ways of representing – and thus thinking about – the human body. Their exhibitions of deviant corporeality and its effect on others anticipate the representation of the human body in film as well as an audience’s reception of a film.
Through its numerous case studies, this monograph is able to show that film history can be told as a history of the representation of the human body. It features discussions of films as diverse as "Der Januskopf", "Nosferatu", "Vampyr", "Le Testament du Docteur Cordelier", "Altered States", "Dorian Gray im Spiegel der Boulevardpresse" and "Bram Stoker’s Dracula".