From being a fictional element in sci-fi, voice control has become a reality, with inventions such as Apple's Siri, and interactive voice response (IVR) when calling your doctor's office. The combination of radio’s strength as a hands-free medium, public radio’s mission to reach across all platforms and the rise of voice makes up a relevant intersection; voice controlled public radio in Sweden. This thesis has aimed to investigate how radio listeners wish to interact using voice control to listen to on-demand radio content. Additionally, what does public radio need to consider when implementing the UX for voice control? A questionnaire, Google Analytics-data from Sveriges Radio’s mobile app and website, and an interview with National Public Radio were used to determine four initial functions voice controlled on-demand. The functions were turned into four scenarios, used as the basis for a workshop and brainstorming session. Three of these scenarios were then selected to be the foundation for a Wizard of Oz-prototype, which six users evaluated. The results indicate that to create a viable voice user interface (VUI) for radio, there needs to be a profile for the user to create a personalized experience, with filtered searches created by user behaviour and preference settings. The VUI also needs to allow synonyms for program names, as well as keyword tag material for clustering similar material and to enable personalized user searches. This keyword-system can further be utilized to give user recommendations based on behaviour and preferences. A companion application with a graphical user interface (GUI) can be used for such functionality as settings, help, queuing and creating playlists. Finally, the system needs to ensure that the users are taken care of and guided. A radio host can be used as a basis for the system's persona, to create a consistent and familiar interface. Aspects to examine in the future are more extensive user testing for the VUI design, filter bubbles, ensuring that the user data is not misused or leaked, dimensions of the system's persona, the future of radio and the progress of IPAs.

Le stannate (SrSnO3) et le titanate de strontium (SrTiO3) sont des oxydes de type pérovskite, de structures orthorhombique (Pbnm) et cubique (Pm3m), respectivement. Ces matériaux ont reçu beaucoup d'attention ces dernières années en raison de leurs propriétés physiques et chimiques intéressantes conduisant à différents types d'applications technologiques. Pour ces raisons, ces deux matériaux ont été combinés pour obtenir la solution solide de SrSn1-xTixO3, sous forme de poudres et couches minces. Au niveau des poudres, la solution solide a présenté des transitions de phases successives allant d'une structure orthorhombique à tétragonale puis cubique avec l’augmentation de la quantité de Ti4+ dans le système. Ces transitions ont été observées par affinement Rietveld des spectres de diffraction des rayons X et confirmées par spectroscopie Raman. Ces différentes structures cristallines ont conduit à des propriétés différentes de photoluminescence dans le spectre visible, l’émission variant d’une région de basse énergie vers les régions de plus haute énergie avec l’augmentation de Ti4+ dans la structure (structure orthorhombique (SrSnO3), tétragonale (SrSn0,75Ti0,25O3) à cubique (SrSn0,50Ti0,50O3, SrSn0,25Ti0,75O3 et SrTiO3). Ces émissions sont probablement favorisées par différents types de défauts formés dans le gap d’énergie de ces matériaux. Par ailleurs, les couches minces ont montré différents types de croissance qui ont été fortement influencés par la nature cristalline du substrat, la composition des films ainsi que par la méthode de dépôt utilisée (dépôt par voie chimique en solution – CSD – et dépôt par ablation laser pulsé – PLD). Les films minces déposés sur silice sont polycristallins (croissance aléatoire des cristallites), les couches sur saphir-R (Al2O3-012) sont également polycristallines mais avec une orientation préférentielle (h00) quand préparées par PLD (croissance texturée), excepté SrTiO3 qui est épitaxié avec une rotation de 45º par rapport au plan du substrat de saphir-R. Tous les films déposés sur LAO (LaAlO3-100) sont épitaxiés (h00) quelque soit la méthode de dépôt. De plus, les caractéristiques morphologiques et les propriétés photocatalytiques des films ont également été fortement influencées par ces mêmes paramètres cités précédemment. Concernant les propriétés photocatalytiques, les films préparés par la méthode CSD ont été plus efficaces que ceux obtenus par PLD et les couches de compositions plus riches en Sn4+ ont été plus actives face à la photodégradation du colorant Remazol jaune or, l’efficacité maximale étant observée pour la couche polycristalline de SrSnO3 obtenue par CSD avec un pourcentage de dégradation et de décoloration d’environ 55 et 90 %, respectivement. Le type de croissance des films de SrSnO3 préparés par les deux méthodes de dépôt a aussi montré une forte influence sur la photodégradation du colorant, les couches polycristallines d’orientation aléatoire obtenues sur silice étant plus efficaces que les texturées, elles-mêmes plus efficaces que les couches épitaxiales. / Strontium stannate (SrSnO3) and titanate (SrTiO3) are perovskite type oxides that have orthorhombic (Pbnm) and cubic (Pm3m) structures, respectively. These materials have received much attention due to their interesting physical and chemical characteristics, leading to a variety of technological applications. In this sense, these two materials were combined to each other in order to obtain powders and thin films of a solid solution, SrSn1-xTixO3. In relation to the powders, this solid solution presented successive phase transitions ranging from orthorhombic and tetragonal structures to a cubic one with increasing of Ti4+ amount in the composition. These transitions were observed by XRD Rietveld refinement of the samples and confirmed by Raman spectroscopy. The different crystalline structures of the compositions within the solid solution led to different photoluminescent properties in the visible spectrum varying the range of emission, moving from a lower energy region to a higher one with increasing of Ti4+ in the structure (from orthorhombic (SrSnO3), tetragonal (SrSn0.75Ti0.25O3) to cubic (SrSn0.50Ti0.50O3 ; SrSn0.25Ti0.75O3 and SrTiO3). These emissions were probably favored by specific defects created inside the band gap of these materials. On the other hand, the thin films of this system showed different growth orientations that are associated to the crystalline nature of the substrates, the composition of the thin films and the deposition method (Chemical Solution Deposition - CSD - and Pulsed Laser Deposition - PLD). The films deposited on silica substrate were polycrystalline (random growth of the crystallites), whereas the films deposited on sapphire-R (Al2O3-012) were also polycrystalline, with a preferred orientation (h00) for the films deposited by PLD (textured growth), except SrTiO3 which was rotated 45° epitaxially in the sapphire plane. On the contrary, all of the films deposited on LAO (LaAlO3-100) had an (h00) epitaxial growth. In addition to that, the morphological characteristics and photocatalytic properties were strongly influenced also by the same parameters described above. Regarding the photocatalytic efficiency of the films, those obtained by CSD were more efficient than the ones obtained by PLD. Moreover, the films with Sn4+ richer compositions were the most active in the photodegradation of the azo dye Remazol yellow gold, reaching a maximum efficiency with the polycrystalline SrSnO3 thin film obtained by CSD whose degradation and decolorization percentage were 55 and 90 %, respectively. The type of orientation of the SrSnO3 films showed also a strong influence on the photodegradation of the dye. The polycrystalline films with a random orientation obtained on silica were more efficient than the textured films and these ones were more than the epitaxial films. / O estanato (SrSnO3) e o titanato de estrôncio (SrTiO3) são óxidos do tipo perovskita que apresentam estrutura ortorrômbica (Pbnm) e cúbica (Pm3m), respectivamente. Estes materiais têm recebido bastante atenção nos últimos anos devido às suas características físicas e químicas interessantes, levando à diferentes tipos de aplicações tecnológicas. Portanto, estes dois materiais foram combinados com intuito de obter uma solução sólida, SrSn1-xTixO3, na forma de pós e filmes finos. Em relação aos pós, esta solução sólida apresentou transições de fase sucessivas com o aumento da quantidade de Ti4+ no sistema, passando de uma estrutura ortorrômbica à tetragonal levando à cúbica. Estas transições foram observadas através de difração de raios-X e refinamento Rietveld, e confirmadas por espectroscopia vibracional Raman. Os diferentes tipos de estrutura cristalina das composições da solução sólida levaram a diferentes propriedades fotoluminescentes no espectro visível, variando a região de emissão de mais baixa à mais alta energia com o aumento de Ti4+ na estrutura, ou seja, passando da estrutura ortorrômbica (SrSnO3), tetragonal (SrSn0,75Ti0,25O3) até à cúbica (SrSn0,50Ti0,50O3, SrSn0,25Ti0,75O3 e SrTiO3). Estas emissões foram provavelmente favorecidas pelos tipos de defeitos específicos criados dentro do band gap destes materiais. Por outro lado, os filmes finos deste sistema apresentaram diferentes tipos de crescimento os quais são associados à natureza cristalina dos substratos, composição dos filmes e com o método de deposição utilizado (método de deposição química em solução - CSD - e método de deposição por laser pulsado – PLD). Os filmes depositados sobre sílica e safira-R (Al2O3-012) apresentaram como policristalinos (crescimento aleatorio dos cristalitos), enquanto os filmes depositados por PLD apresentaram orientação preferencial (h00) (crescimento texturizado), com exceção do filme de SrTiO3 que é epitaxial rotacionado em 45º no plano da safira-R. Todos os filmes depositados através dos dois métodos de deposição sobre LAO (LaAlO3-100) apresentaram um crescimento epitaxial (h00). Além disso, as características morfológicas e as propriedades fotocatalíticas também apresentaram forte influencia dos mesmos parâmetros acima citados. Em relação às propriedades fotocatalíticas, os filmes obtidos pelo método CSD apresentaram maior eficiência que os obtidos por PLD e os filmes com composições mais ricas em Sn4+ foram os mais ativos na fotodegradação do corante azo Remazol amarelo ouro, chegando a uma eficiência fotocatalítica máxima com o filme policristalino de SrSnO3 obtido por CSD com percentagem de degradação e de descoloração de 55 e 90 %, respectivamente. A orientação dos filmes de SrSnO3 também mostrou uma forte influencia na fotodegradação do corante, sendo os filmes policristalinos com orientação aleatória mais eficiente que o texturizado e estes por sua vez mais eficientes que os epitaxiais.

Characterising the geochemistry and speciation of major contaminant radionuclides is crucial in order to understand their behaviour and migration in complex environmental systems. Organic complexing agents used in nuclear decontamination have been found to enhance migration of radionuclides at contaminated sites; however, the mechanisms of the interactions in complex environments are poorly understood. In this work, radionuclide speciation and sorption behaviour were investigated in order to identify interactions between four key radionuclides with different oxidation states (Cs(I) and Sr(II) as important fission products; Th(IV) and U(VI) as representative actinides), three anthropogenic organic complexing agents with different denticities (EDTA, NTA and picolinic acid as common co-contaminants), and natural sand (as simple environmental solid phase). A UV spectrophotometric and an IC method were developed to monitor the behaviour of EDTA, NTA and picolinic acid in the later experiments. The optimised methods were simple, applied widely-available instrumentation and achieved the necessary analytical figures of merit to allow a compound specific determination over variable background levels of DOC and in the presence of natural cations, anions and radionuclides. The effect of the ligands on the solubility of the radionuclides was studied using a natural sand matrix and pure silica for comparison of anions, cations and organic carbon. In the silica system, the presence of EDTA, NTA and, to a lesser extent, picolinic acid, showed a clear net effect of increasing Th and U solubility. Conversely, in the sand system, the sorption of Th and U was kinetically controlled and radionuclide complexation by the ligands enhanced the rate of sorption, by a mechanism identified as metal exchange with matrix metals. Experiments in which excess EDTA, NTA and picolinic acid (40 – 100 fold excess) were pre-equilibrated with Th and U prior to contact with the sand, to allow a greater degree of radionuclide complex formation, resulted in enhanced rates of sorption. This confirmed that the radionuclide complexes interacted with the sand surface more readily than uncomplexed Th or U. Overall this shows that Th and U mobility would be lowered in this natural sand by the presence of organic co-contaminants. In contrast, the complexation of Sr with the complexing agents was rapid and the effect of the ligands was observed as a net increase on Sr solubility (EDTA, picolinic acid) or sorption (NTA). As expected, Cs did not interact with the ligands, and showed rapid sorption kinetics. Finally, ESI-MS was used to study competitive interactions in the aqueous Th-Mn-ligand ternary system. Quantification presented a challenge, however, the careful approach taken to determine the signal correction allowed the competitive interactions between Mn and Th for EDTA to be studied semi-quantitatively. In an EDTA limited system, Th displaced Mn from the EDTA complex, even in the presence of a higher Mn concentration, which was consistent with the higher stability constant of the Th-EDTA complex.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

One of the cornerstones of the R system for statistical computing is the multitude of contributed packages making an extremely broad range of statistical techniques and other quantitative methods freely available. This study investigates which factors are the crucial determinants responsible for the participation of the package authors in the R project. For this purpose a survey was conducted among R package authors, collecting data on different types of participation in the R project, three psychometric scales (hybrid forms of motivation, work design characteristics, and values), as well as various specie-demographic factors. These data are analyzed using item response theory and generalized linear models, showing that the most important determinants for participation are a hybrid form of motivation and the knowledge characteristics of the work design. Other factors are found to have less impact or influence only specific aspects of participation. (authors' abstract) / Series: Research Report Series / Department of Statistics and Mathematics

Le système volcanique de La Réunion est formé de la coalescence des massifs du Piton des Neiges et du Piton de la Fournaise. Son édification, liée à l’activité d’un panache mantellique, est caractérisée par une phase de croissance sous-marine, puis subaérienne, suivie d’une période de dégénérescence, comme proposé classiquement pour les volcans boucliers océaniques d’Hawaii. De précédentes études ont montré que l’activité subaérienne de La Réunion aurait débuté il y a environ 2,2 Ma. Les analyses géochimiques menées jusqu’alors sur les produits associés à cette activité volcanique (subaérienne et sous-marine) ont montré un caractère chimique transitionnel avec une composition isotopique (87Sr/86Sr, 143Nd/144Nd et 176Hf/177Hf) particulièrement homogène pour un volcanisme de point chaud. Dans cette étude, nous montrons que des laves sous-marines récemment identifiées sous la série basique du Piton de la Fournaise (au sein de la sur Rift Zone Nord-Est) ainsi que des laves subaériennes affleurant à la base de canyons incisés dans le massif (Série Différenciée de la Rivière des Remparts), présentent des caractéristiques ne s’inscrivant pas dans le modèle d’évolution proposé précédemment pour ce volcan. Se pose donc la question de la nature et de l’origine de ces laves, ainsi que de leur place et appartenance dans l’édification du système volcanique réunionnais. De nouvelles investigations pétro-géochimiques et géochronologiques ont été menées sur la partie sous-marine de l’édifice de La Réunion. Elles révèlent l’existence d’un groupe de laves exceptionnel. Leur composition se distingue clairement de celle des échantillons communément analysés à La Réunion et montre (1) un enrichissement en éléments incompatibles couplé isotopiquement à (2) un rapprochement vers un pôle mantellique enrichi de type EM. Ces particularités géochimiques démontrent que le panache mantellique possède (1) une source hétérogène affectée par (2) des taux de fusion variables. De plus, deux échantillons de ce nouveau groupe datés à 3,77 (0,08) et à 3,34 (0,07) Ma étendent considérablement la période d’activité connue de l’édifice. Ces âges remarquables font de ces laves les plus anciennes jamais datées à La Réunion. La nature géochimique ainsi que la position stratigraphique des laves de cette étude (échantillons subaériens et sous-marins des massifs du Piton des Neiges et du Piton de la Fournaise) impliquent une réinterprétation du schéma d’évolution global de l’île. Contrairement aux études précédentes, nos résultats sur ces laves montrent que : (1) Les laves différenciées de la Rivière des Remparts, qui sont des laves subaériennes, de part leur position stratigraphique et géographique sous-jacente au Piton de la Fournaise et par analogie avec le Piton des Neiges, ne peuvent être reliées à l’activité de la Fournaise, (2) Le signal isotopique du groupe de laves sous-marines de la Rift Zone Nord-Est de la Fournaise, révèlent l’hétérogénéité de la source du panache mantellique sous La Réunion, source que nous identifions comme des enclaves d’éclogite contenues dans une lherzolite à spinelle, (3) L’âge plus ancien de ces laves sous-marines et leur localisation sous le flanc Est de la Fournaise remet en questions le schéma jusqu’alors admis pour l’édification de l’île de La Réunion reposant sur la construction du Piton des Neiges puis celle, adjacente, du Piton de la Fournaise. En conséquence, nos données géochimiques et géochronologiques sont de nouveaux arguments en faveur de l’élaboration d’un modèle d’évolution plus complexe, suggérant l’existence d’un troisième massif volcanique. Il est en accord avec les précédents travaux de pétrologie et de géophysique suggérant l’existence d’un troisième édifice à l’Est de La Réunion, communément appelé le Volcan des Alizés. / The volcanic system of La Reunion is made of the coalescent Piton des Neiges and Piton de la Fournaise edifices. Its formation, associated with the activity of a mantle plume, is characterized by phases of submarine and subaerial growth, followed by a period of destruction, as described in the classical model proposed for Hawaiian Island volcanoes. Previous studies showed that the subaerial activity of La Reunion would have started around 2.2 Ma ago. Geochemical analyses carried out on the products associated with subaerial and submarine volcanism revealed their transitional chemical nature and their peculiar homogeneous isotopic compositions (87Sr/86Sr, 143Nd/144Nd et 176Hf/177Hf) for a hotspot derived magmatism. In this study, we show that some unusual submarine lavas were recently identified below the basal series of Piton de la Fournaise volcano (dredged on the North-East Rift Zone of la Fournaise) and below the subaerial lavas outcropping at the base of the differentiated series of Rivière des Remparts, indicate that the evolution of La Reunion system is probably more complex than previously suggested. The question of the nature and origin of these lavas, together with their implication on the formation of La Reunion, is an issue of major interest in order to better constrain the global evolution of the volcanic system. As a consequence, new petrological, geochemical and geochronological investigations were conducted on the submarine part of La Reunion edifice. They revealed the existence of a geochemically exceptional group of lavas. Its composition is clearly different from common samples of La Reunion and presents (1) an enrichment in incompatible elements and (2) tends toward an enriched EM endmember. These chemical specificities reveal that the source of La Reunion magmatic products is (1) an heterogeneous source affected by (2) variable melting degrees. Moreover, two samples of this new group dated at 3.77 (0,08) and 3.34 (0,07) Ma extend considerably the period of activity of the island. These rocks are the oldest samples ever dated at La Reunion. The nature and stratigraphical location of subaerial and submarine samples from Piton des Neiges and Piton de la Fournaise imply a new interpretation of the global evolution of the island. Unlike previous studies, our results indicate that :(1) The differentiated subaerial lavas from Rivière des Remparts, due to their stratigraphical and geographical location underlying Piton de la Fournaise, and by analogy with the Piton des Neiges, cannot be linked to the activity of Piton de la Fournaise. (2) The isotope signature of the submarine lava group from the North-East Rift Zone of Piton de la Fournaise, reveals the heterogeneous character of the mantle source under La Reunion Island, that can be modelled as embedded eclogite in a matrix of spinel lherzolite, (3) The age of this submarine group and its location under the eastern flank of Piton de la Fournaise, imply a more complex model of evolution of La Reunion. Therefore, our geochemical and geochronological data are new arguments suggesting the existence of a third volcanic center on the island. This assumption confirms the previous petrological and geophysical evidence supporting the existence of this volcano at the East of La Reunion, commonly called Les Alizés volcano.

The financial situations of households are among the key factors influencing the market in the country. This thesis focuses on analyzing and evaluating the potential and financial position of Czech and Slovak households. It deals mainly with the analysis of data from the years 2004 to 2008, which is the period of the entrance of Slovakia and the Czech Republic into the European Union. The theoretical section describes events in particular, the economic and financial situation of households in those two countries during the observed years. The practical process uses different types of statistical methods and analysis to identify the financial situation in the Czech Republic and Slovakia, as well as identify the differences between them. The conclusion summarizes the findings and observations of the research findings, which are implemented in the practical section.

Die Informations- und Kommunikationstechnologien haben die Arbeitswelt grundlegend verändert. Durch den Einsatz komplexer, hochautomatisierter Systeme werden an die kognitive Leistungsfähigkeit und Belastbarkeit von Arbeitnehmern hohe Anforderungen gestellt. Über die Ermittlung der psychischen Beanspruchung des Menschen an Arbeitsplätzen mit hohen kognitiven Anforderungen wird es möglich, eine Über- oder Unterbeanspruchung zu vermeiden. Gegenstand der Dissertation ist deshalb die Entwicklung, Implementierung und der Test eines neuen Systems zur kontinuierlichen Bewertung psychischer Beanspruchung an informationsintensiven Arbeitsplätzen auf Basis des Elektroenzephalogramms. Im theoretischen Teil der Arbeit werden die Konzepte zur Definition der psychischen Beanspruchung und Modelle zur Beschreibung der menschlichen Informationsverarbeitung zusammengestellt. Die Auswertung einer Reihe von Experimenten ist die Basis für die Konzeption und den Test des neuen Systems zur Indexierung der psychischen Beanspruchung. Die Aufgabenbatterie, die Stichprobenbeschreibung, der Versuchsaufbau und -ablauf sind Bestandteil des experimentellen Teils der Arbeit. Während der Aufgabenlösung wird von den Probanden das Elektroenzephalogramm mit 25 Kanälen abgeleitet. Es folgt eine Artefakteliminierung, für die ein neues automatisch und in Echtzeit arbeitendes Verfahren entwickelt wurde. Die Klassifikation und damit die Indexierung von Segmenten des Elektroenzephalogramms in die Klassen niedriger, mittlerer oder hoher Beanspruchung erfolgt auf Basis einer ebenfalls neu entwickelten Methode, deren Grundlage Dual Frequency Head Maps sind. Damit ist ein vollständiges System entstanden, das die einzelnen Verfahrensschritte integriert und die Aufgabenstellung der Arbeit erfüllt: Es kann an informationsintensiven Arbeitsplätzen eingesetzt werden, um kontinuierlich die Bewertung der psychischen Beanspruchung auf Basis des Elektroenzephalogramms vorzunehmen. / Advanced information and communication technology has fundamentally changed the working environment. Complex and highly automated systems impose high demands on employees with respect to cognitive capacity and the ability to cope with workload. The registration of mental workload of employees on-site at workplaces with high cognitive demands enables preventing over- or underload. The subject of this dissertation is therefore the development, implementation and testing of a novel system for continuous assessment of mental workload at information intensive workplaces on the basis of the electroencephalogram. In the theoretical section of the thesis concepts for defining mental workload are given; furthermore, models for describing human information processing are introduced and the relevant terminology such as strain, workload, and performance is clarified. Evaluation of an array of experiments with cognitive tasks forms the basis for the conceptual design and testing of the novel system for indexing mental workload. Descriptions of these tasks, the sample, the experimental set-up and procedure are included in the experimental section. The electroencephalogram with 25 channels was recorded from the subjects while performing the tasks. Subsequently, an artifact elimination was carried out, for which a new, automated, and real-time capable procedure has been developed. Segments from the electroencephalogram are classified and thusly indexed into classes of low, medium, and high workload on the basis of a likewise newly developed method, whose central element are Dual Frequency Head Maps. Hence, a complete system emerges that integrates the single processing steps and satisfies the scope of this thesis: It can be applied on-site at information intensive workplaces for continuous assessment of mental workload on the basis of the electroencephalogram.

Die Ansprüche von Kunden an neue (Software-)Produkte wachsen stetig. Produkte sollen genau auf die einzelnen Kundenwünsche zugeschnitten sein, sodass der Kunde genau die Funktionalität erhält und bezahlt die er benötigt. Hersteller reagieren auf diese gestiegenen Ansprüche mit immer mehr Varianten in denen sie ihre Produkte ihren Kunden anbieten. Die Variantenvielfalt hat in solchem Maß zugenommen, dass selbst in Massen gefertigte Produkte heute als Unikate produziert werden können. Neue Methoden wie Produktlinienentwicklung unterstützen die Entwicklung solcher variantenreicher Systeme. Während der Aufwand für die Entwicklung neuer Varianten nun sinkt, profitiert die Qualitätssicherung nicht vom Effizienzgewinn der Entwicklung. Im Gegenteil: Insbesondere beim Test wird zunächst jede Variante wie ein einzelnes Produkt behandelt. Bei variantenreichen Systemen ist dies aufwandsbedingt jedoch nicht mehr möglich. Die in dieser Arbeit vorgestellten Testentwurfsmethoden berücksichtigen die Variantenvielfalt in besonderem Maße. Bisher wurden, nach einer Stichprobenauswahl zur Reduktion des Testaufwands, die Testfälle auf Basis der konkreten Produkte entworfen. Statt nun auf Basis konkreter Produkte werden in dieser Arbeit zwei Ansätze vorgestellt, die die Phase des Testentwurfs auf die Produktlinienebene heben. Die bei Anwendung dieser Methoden entstehenden Testfälle enthalten, je nach Inhalt, Freiheitsgrade bzgl. ihrer Anforderungen an eine Variante, sodass ein Testfall auf ein oder mehrere Varianten angewendet wird. Ausgehend von solchen Testfällen werden in dieser Arbeit neue Kriterien zur Stichprobenauswahl entwickelt. Mit diesen Kriterien kann der Umfang der Stichprobe, aber auch Eigenschaften der zu testenden Varianten bzgl. eines gegebenes Testziel optimiert werden. So ist es möglich, z.B. sehr wenige oder sehr unterschiedliche Varianten zum Test auszuwählen. Insgesamt werden in dieser Arbeit fünf Kriterien definiert und auf ihr Fehleraufdeckungspotenzial untersucht. Zu diesem Zweck werden neue Bewertungskriterien zur Fehleraufdeckungswahrscheinlichkeit von Produktlinientests etabliert. Somit ist erstmalig eine quantitative sowie qualitative Bewertung von Produktlinientests möglich. Die Ergebnisse der vorgestellten Methoden und Auswahlkriterien werden sowohl untereinander evaluiert, als auch konventionellen Testmethoden für Produktliniensysteme gegenübergestellt. An vier Beispielen unterschiedlicher Gro{\"ss}e werden die in dieser Arbeit vorgestellten Methoden evaluiert. / Consumer expectations of (software-)products are growing continuously. They demand products that fit their exact needs, so they pay only for necessary functionalities. Producers react to those demands by offering more variants of a product. Product customization has reached a level where classically mass produced goods, like cars, can be configured to unique items. New paradigms facilitate the engineering of such variant-rich systems and reduce costs for development and production. While development and production became more efficient, quality assurance suffers from treating each variant as a distinct product. In particular, test effort is affected, since each variant must be tested sufficiently prior to production. For variant-rich systems this testing approach is not feasible anymore. The methods for test design presented in this thesis overcome this issue by integrating variability into the test design process. The resulting test cases include requirements for variants, which must be fulfilled to execute the test successfully. Hence multiple variants may fulfill these requirements, each test case may be applicable to more than only one variant. Having test cases with requirements enables sampling subsets of variants for the purpose of testing. Under the assumption that each test case must be executed once, variants can be sampled to meet predefined test goals, like testing a minimal or diverse subset of variants. In this thesis, five goals are defined and evaluated by assessing the tests for their fault detection potential. For this purpose, new criteria for assessing the fault detection capability of product line tests are established. These criteria enable quantitative as well as qualitative assessment of such test cases for the first time. The results of the presented methods are compared with each other and furthermore with state of the art methods for product line testing. This comparison is carried out on four examples of different sizes, from small to industry-grade.

Physical-Computing-Geräten wie Robotern und Mikrocontrollern wird eine wichtige Rolle als Lernmedium für Schülerinnen und Schüler zugesprochen. Zu lernende Kontexte sind ähnlich vielfältig wie die inzwischen existierenden Geräte. Die Komplexität der Systeme ist mannigfaltig und bisherige Forschung geht zumeist von dem Gerät als Forschungsgegenstand aus. Im Rahmen dieser Dissertation wird von einem geräteunabhängigen Physical- Computing-Prozess als Problemlöseprozess ausgegangen, um ein Fundament für nachhaltige und geräteunabhängige Forschung zu schaffen sowie Physical Computing als Unterrichtsgegenstand zu beschreiben. Aufgrund von Merkmalen, wie der Arbeit mit Sensorik und Aktuatorik sowie dem iterativen Testen und Evaluieren, scheint Physical Computing Ähnlichkeiten zu dem naturwissenschaftlichen Experiment aufzuweisen. Dieser Zusammenhang und die potentiellen Auswirkungen auf die Informatikdidaktik werden in den folgenden drei Ausprägungsformen untersucht. Basierend auf Modellen aus der Literatur wird ein Modell des Physical-Computing- Prozesses abgeleitet und mithilfe empirischer Studien adaptiert. Bei dem Vergleich der Prozesse der wissenschaftlichen Erkenntnisgewinnung und des Physical Computing können diverse Gemeinsamkeiten festgestellt werden. Insbesondere verlaufen die Prozesse parallel zueinander, was die Grundlage für einen MINT-Problemlöseprozess bildet. Bislang wurden konkrete Probleme von Schülerinnen und Schülern bei der Interaktion mit den Geräten peripher beschrieben. In dieser Arbeit wird eine Analyse von Problemursachen vorgenommen und auftretende Probleme werden kategorisiert. Probleme, die gleichzeitig mehrere Problemursachen haben, werden aufgedeckt und eine Problemtaxonomie zur Beschreibung von Problemursachen abgeleitet. Ein mehrstufiges Feedback-Modell zur Unterstützung des Problemlösens in Physical- Computing-Aktivitäten wird basierend auf der Problemtaxonomie entwickelt. Durch eine empirische Untersuchung wird es als unterstützend für den Physical-Computing-Prozess evaluiert und bildet damit ein Modell zur Entwicklung von kognitiven Tutorensystemen für Physical Computing. / Physical computing devices like robots and microcontrollers play an important role as learning devices for students. These devices as well as the learning contexts are multifaceted. The complexities of the systems are diverse and the existing research is usually concentrated on the devices. This thesis develops as a starting point a device-independent physical computing process by seeing it as problem-solving process. The goal is to construct a base for sustained and device-independent physical computing research and to describe physical computing as a school subject. The physical computing process seems to share similarities with the scientific inquiry process, because of characteristics like working with sensors and actuators and iterativ testing and evaluating. This relation and the implications on computer science education are explored in the following three facets. Based on existing literature, a model of the physical computing process is derived and supplemented by empirical data. In the comparison of the scientific inquiry and the physical computing processes substantial commonalities are identified. Hence, a base for a joint STEM problem-solving process is built. So far, concrete students’ problems during the activities with physical computing devices are described as a side product. In this thesis problem sources are uncovered and occurring problems categorized. Problems having more than one problem source are uncovered and a problem taxonomy is derived from that. Based on the problem taxonomy, a multilevel feedback model to support problem solving during physical computing activities is developed. With an empirical exploration, the taxonomy is evaluated. Results indicate that the taxonomy is supportive for achieving the physical computing process. Finally a model for a cognitive tutoring system for physical computing is outlined.