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Microbiology honours students' conceptual development during a beer brewing teaching learning sequence (TLS)Tekane, Rethabile Reginalda. January 2010 (has links)
Brewing is defined as “the combined processes of preparing beverages from the infusion of sound grains that have undergone sprouting, and the subsequent fermentation of the sugary solution produced, by yeast-whereby a proportion of the carbohydrate is converted to ethanol and carbon-dioxide.” It is a complex process that requires knowledge of concepts from disciplines such as biochemistry, chemistry, engineering, microbiology and physics. The micro-brewery apparatus at the University of KwaZulu-Natal is used by the discipline of microbiology as part of a brewing exercise to introduce students to industrial microbiology with the aim of developing their conceptual understanding of the process. So far, though, no research has been conducted in order to fully establish the effectiveness of this exercise in developing such understanding of the brewing process. The aim, therefore, of this study was to investigate the effectiveness of a micro-brewing Teaching-Learning Sequence (TLS) that incorporates the micro-brewery, for promoting students‟ understanding of the scientific concepts of relevance to the brewing process. The following research questions were addressed: 1) What concepts are essential for understanding the process of beer brewing? 2) Did those students with sound conceptions develop deeper understanding during the TLS? 3) Did students show any conceptual difficulties with the brewing concepts? 4) Did any remediation of such difficulties occur during the TLS? 5) Did students show retention of (mis)understanding two months after the brewing practical? 6) What were students‟ attitudes and motivational levels like during the brewing practical? 7) How well did students rate their experiences of the whole TLS? 8) How well did students‟ motivational levels and their rating of the TLS correlate with any changes in understanding? The study involved ten microbiology honours students subjected to a TLS which consisted of: i) three brewing lectures aimed at introducing students to the brewing process; ii) pre- & post tests including concept mapping tasks aimed at addressing research questions 2, 3 & 4; iii) a brewing practical aimed at facilitating students‟ development of mental models and conceptual understanding of the brewing process and their motivation and attitude to this exercise (addressing question 6 & 8); iv) a group discussion which involved a group tasting session and the evaluation and discussion of each group‟s final beer product; v) semi-structured interviews to establish the source (s) of students‟ difficulties and their retention of knowledge or difficulties (questions 2, 4, & 5 addressed); and vi) an evaluation questionnaire aimed at obtaining student opinion of the TLS (addressing question 7). The data obtained was analyzed via inductive analysis. The results revealed the following brewing difficulties: i) belief that glycolysis reactions are non-consecutively linked chemical reactions which are independent of one another; ii) confusion that whirl-pooling cools the wort; and iii) belief that the final specific gravity value is a measure of the amount of sugars converted to ethanol. Comparison between the pre- & post test responses indicated that some students‟ (B, D & K) conceptual understanding including integrated knowledge of the brewing process improved during the TLS and their brewing difficulties were remediated. In contrast, other students‟ (A, C, E, G, H, J & I) conceptual understanding did not improve during the TLS and their brewing difficulties were not remediated. There was also a positive correlation between student attitudes and motivation towards the brewing practical and the quality of their learning outcomes. Students (B, D & K) who showed high motivational levels and cognitively and physically took part in the TLS showed improved conceptual understanding of the brewing process and retention of knowledge, while those showing low motivational levels did not improve. Furthermore, there are students (G, H & J) who showed high motivational levels during the TLS but their conceptual understanding of the brewing process did not improve. The results obtained suggest that the TLS, based on the micro-brewery apparatus, was at least partially effective in facilitating the development of students‟ conceptual understanding and visualization of the brewing process and the remediation of some of their difficulties, which in some case correlated well with their motivational levels and attitudes towards the brewing exercise. More research is however required to fully confirm the usefulness of such TLSs in brewing education. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.
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Conceptualisation infographique pour la réalisation d'une oeuvre plastique /Tremblay, Agnès, January 1988 (has links)
Mémoire (M.A.)-- Université du Québec à Chicoutimi, 1988. / Ce travail de recherche a été réalisé à l'Université du Québec à Chicoutimi dans le cadre du programme de maîtrise en arts plastiques extensionné de l'Université du Québec à Montréal à l'Université du Québec à Chicoutimi. CaQCU Bibliographie : p. 29-32. Document électronique également accessible en format PDF. CaQCU
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Cognitive mapping : an alternate lesson strategyElston, Wilma 18 March 2014 (has links)
D.Ed. (Teaching Studies) / The traditional method of lesson presentation has in recent years come under scrutiny from various education quarters concerned with approaches to teaching and learning. The reason for this being the changing swing of thoughts concerning knowledge and learning, the new integrated lifelong learning approach for general and further education (NQF:1995a) and the shift of emphasis in teaching strategies. The realization has dawned on educationalists that presentation lessons should perhaps not be "the one skill to which most attention is directed during [in-service] training" (Ashman & Conway, 1993:61), but one of many skills that should receive undue attention by all lesson presenters. The aim has not been to eradicate the process of lesson presentation in its present format but rather to oscillate the emphasis due to the growing interest in the manner in which learning matter is presented (Durniny & Sohnge, 1986:98). Learning activities should be "planned in such as way that most [all] of the learners are involved in [thinking] activities at all times of the lesson and not excluded as commonly appears to be the case" (Elston, 1992:71). Unfortunately initiative, creativity and other teacher input is not a prerequisite for lesson and content presentation as is proven when examining policies brought about by education departments regarding requirements for the planning and presentation of lessons. It must however be mentioned that these are changing drastically and we, as educators in so doing have to adapt (Osborne, 1993:2). Hardy (1992:56) believes that there should always be a prototype [lesson plan] according to which all instructional activities should take place. Obviously some structure or guidelines are essential, especially pertaining to new, inexperienced teachers, but has one not been "too reliant for too long on hierarchical and sanction ridden modes of 'instructional supervision'" (Smyth, 1991:81) which includes lesson presentation...
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Knowledge Discovery for Avionics Maintenance : An Unsupervised Concept Learning Approach / Découverte de connaissances pour la maintenance avionique : une approche d'apprentissage de concepts non superviséePalacios Medinacelli, Luis 04 June 2019 (has links)
Dans cette thèse, nous étudions le problème de l’analyse de signatures de pannes dans le domaine de la maintenance avionique, afin d’identifier les défaillances au sein d’équipements en panne et suggérer des actions correctives permettant de les réparer. La thèse a été réalisée dans le cadre d’une convention CIFRE entre Thales Research & Technology et l’Université Paris-Sud. Les motivations sont donc à la fois théoriques et industrielles. Une signature de panne devrait fournir toutes les informations nécessaires pour identifier, comprendre et réparer la panne. Pour comprendre le mécanisme la panne son identification doit donc être explicable. Nous proposons une approche à base d’ontologies pour modéliser le domaine d’étude, permettant une interprétation automatisée des tests techniques réalisés afin d’identifier les pannes et obtenir les actions correctives associées. Il s’agit d’une approche d’apprentissage de concepts permettant de découvrir des concepts représentant les signatures de pannes tout en fournissant des explications sur les choix de propositions de réparations. Comme les signatures ne sont pas connues a priori, un algorithme d’apprentissage automatique non supervisé approxime les définitions des concepts. Les signatures apprises sont fournies sous forme de définitions de la logique de description (DL) et ces définitions servent d’explications. Contrairement aux techniques courantes d’apprentissage de concepts conçues pour faire de l’apprentissage supervisé ou basées sur l’analyse de patterns fréquents au sein de gros volumes de données, l’approche proposée adopte une perspective différente. Elle repose sur une construction bottom-up de l’ontologie. Le processus d’apprentissage est réalisé via un opérateur de raffinement appliqué sur l’espace des expressions de concepts et le processus est guidé par les données, c’est-à-dire les individus de l’ontologie. Ainsi, les notions de justifications, de concepts plus spécifiques et de raffinement de concepts ont été révisées et adaptées pour correspondre à nos besoins. L’approche a ensuite été appliquée au problème de la maintenance avionique. Un prototype a été implémenté et mis en œuvre au sein de Thales Avionics à titre de preuve de concept. / In this thesis we explore the problem of signature analysis in avionics maintenance, to identify failures in faulty equipment and suggest corrective actions to resolve the failure. The thesis takes place in the context of a CIFRE convention between Thales R&T and the Université Paris-Sud, thus it has both a theoretical and an industrial motivation. The signature of a failure provides all the information necessary to understand, identify and ultimately repair a failure. Thus when identifying the signature of a failure it is important to make it explainable. We propose an ontology based approach to model the domain, that provides a level of automatic interpretation of the highly technical tests performed in the equipment. Once the tests can be interpreted, corrective actions are associated to them. The approach is rooted on concept learning, used to approximate description logic concepts that represent the failure signatures. Since these signatures are not known in advance, we require an unsupervised learning algorithm to compute the approximations. In our approach the learned signatures are provided as description logics (DL) definitions which in turn are associated to a minimal set of axioms in the A-Box. These serve as explanations for the discovered signatures. Thus providing a glass-box approach to trace the reasons on how and why a signature was obtained. Current concept learning techniques are either designed for supervised learning problems, or rely on frequent patterns and large amounts of data. We use a different perspective, and rely on a bottom-up construction of the ontology. Similarly to other approaches, the learning process is achieved through a refinement operator that traverses the space of concept expressions, but an important difference is that in our algorithms this search is guided by the information of the individuals in the ontology. To this end the notions of justifications in ontologies, most specific concepts and concept refinements, are revised and adapted to our needs. The approach is then adapted to the specific avionics maintenance case in Thales Avionics, where a prototype has been implemented to test and evaluate the approach as a proof of concept.
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Science text: Facilitating access to physiology through cognition-based reading interventionWesso, Iona January 1995 (has links)
Philosophiae Doctor - PhD / Reading and understanding science text is the principal means by which students at tertiary level access scientific information and attain scientific literacy. However, understanding and learning from science texts require cognitive processing abilities which students mayor may
not have. If students fail to understand scientific text, their acquisition of subject knowledge and expertise will be impeded and they will fail to develop into thinking and independent learners, so crucial for academic progress and achievement. A major assumption in this study
is thus that in order to increase access to science subjects there is a need to explicitly teach the thinking abilities involved in learning science from text. A review of the literature showed that while reading to learn from scientific text poses special challenges to students faced with this unfamiliar genre, little is known about reading (and thinking) for science learning. A synthesis of current research which describes the
neglected interface between science learning, science reading and cognition is given in the literature review of this study. This synthesis highlights, in particular, the parallel developments in research into science learning and reading; the lack of integration of research in these areas; the absence of investigations on science reading located within the cognitive domain; and the absence of research into reading as it affects cognition and cognition as it affects reading in subject-specific areas such as physiology Possibilities for improving students' cognitive performance in reading to learn through intervention were considered from a cognitive perspective. From this perspective, students'
observable intellectual performance can be attributed to their underlying knowledge, behaviour, and thought processes. Accordingly, the mental processes involved in comprehending scientific concepts from text and the cognitive processes which the students bring to the learning situation become highly relevant to efforts to improve cognitive skills for learning science Key questions which were identified to serve as a basis for intervention included: a) What cognitive abilities are needed for competent reading comprehension as demanded by
physiology text?; b) How adequate is the cognitive repertoire of students in dealing with physiology text? With regard to these questions a catalogue of cognitive functions as formulated by Feuerstein et al (1980) was identified as optimally suited for establishing the cognitive match between reading tasks and students. Micro-analyses of the cognitive demands of students' textbook material and the cognitive make-up of second-year university students revealed a profound mismatch between students and their learning material. Students lacked both comprehension fostering and comprehension monitoring abilities appropriate to the demands of the learning task. The explication of the cognitive requirements which physiology text demands served as a basis for systematically designing instruction whereby appropriate intellectual performance for scientific comprehension from text may be attained Subsequent intervention was based on the explicit teaching of thinking abilities within the context of domain-specific (physiology) knowledge. An instructional framework was developed that integrated cognitive learning theories and instructional prescriptions to achieve an effective learning environment and improve students' cognitive abilities to employ and extend their knowledge. The objective was that the instructional model and resultant instructional methods would ensure that students learn not only the desired kinds of knowledge by conceptual change, but also the thought processes embedded and required by reading scientific material for appropriate conceptual change to take place. Micro-analysis of the cognitive processes intrinsic to understanding physiology text illuminated cognitive demands such as, for example, the ability to: transform linearly presented material into structural patterns which illuminate physiological relationships; analyse conceptually dense text rich in "paradoxical jargon"; activate and retrieve extensive amounts of topic-specific and subject-specific prior knowledge; to visualise events; and contextualise concepts by establishing an application for it. Within the above instructional setting, the study shows that the notion of explicitly teaching the cognitive processes intrinsic to physiology text is possible. By translating the cognitive processes into cognitive strategies such as assessing the
situation, planning, processing, organisation, elaboration, monitoring and reflective responses, the heuristic approach effectively served to guide students through various phases of learning from text. Systematic and deliberate methods of thought that would enhance students
problem-solving and thinking abilities were taught. One very successful strategy for learning from physiology text was the ability to reorganise the linearly presented information into a different text structure by means of the construction of graphic organisers. The latter allowed students to read systematically, establish relationships between concepts, identify important ideas, summarise passages, readily retrieve information from memory, go beyond the given textual information and very effectively monitor and evaluate their understanding In addition to teaching appropriate cognitive strategies as demanded by physiology text, this programme also facilitated an awareness of expository text conventions, the nature of physiological understanding, the value of active strategic involvement in constructing
knowledge and the value of metacognitive awareness. Also, since the intervention was executed within the context of physiology content, the acquisition of content-specific information took place quite readily. This overcame the problem of transfer, so often experienced with "content-free" programmes. In conclusion, this study makes specific recommendations to improve science education. Inparticular, the notion of teaching the appropriate cognitive behaviour and thought processes as demanded by academic tasks such as reading to learn physiology seems to be a particularly fruitful area into which science educational research should develop and be encouraged.
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Connecting Unsupervised and Supervised Categorization Behavior from a Parainformative PerspectiveDoan, Charles A. 12 June 2018 (has links)
No description available.
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Grade 11 mathematics learner's concept images and mathematical reasoning on transformations of functionsMukono, Shadrick 02 1900 (has links)
The study constituted an investigation for concept images and mathematical reasoning of
Grade 11 learners on the concepts of reflection, translation and stretch of functions. The
aim was to gain awareness of any conceptions that learners have about these
transformations. The researcher’s experience in high school and university mathematics
teaching had laid a basis to establish the research problem.
The subjects of the study were 96 Grade 11 mathematics learners from three conveniently
sampled South African high schools. The non-return of consent forms by some learners
and absenteeism during the days of writing by other learners, resulted in the subsequent
reduction of the amount of respondents below the anticipated 100. The preliminary
investigation, which had 30 learners, was successful in validating instruments and
projecting how the main results would be like. A mixed method exploratory design was
employed for the study, for it was to give in-depth results after combining two data
collection methods; a written diagnostic test and recorded follow-up interviews. All the 96
participants wrote the test and 14 of them were interviewed.
It was found that learners’ reasoning was more based on their concept images than on
formal definitions. The most interesting were verbal concept images, some of which were
very accurate, others incomplete and yet others exhibited misconceptions. There were a lot of inconsistencies in the students’ constructed definitions and incompetency in using
graphical and symbolical representations of reflection, translation and stretch of functions.
For example, some learners were misled by negative sign on a horizontal translation to the right to think that it was a horizontal translation to the left. Others mistook stretch for
enlargement both verbally and contextually.
The research recommends that teachers should use more than one method when teaching
transformations of functions, e.g., practically-oriented and process-oriented instructions,
with practical examples, to improve the images of the concepts that learners develop.
Within their methodologies, teachers should make concerted effort to be aware of the
diversity of ways in which their learners think of the actions and processes of reflecting,
translating and stretching, the terms they use to describe them, and how they compare the
original objects to images after transformations. They should build upon incomplete
definitions, misconceptions and other inconsistencies to facilitate development of accurate
conceptions more schematically connected to the empirical world. There is also a need for
accurate assessments of successes and shortcomings that learners display in the quest to
define and master mathematical concepts but taking cognisance of their limitations of
language proficiency in English, which is not their first language. Teachers need to draw a
clear line between the properties of stretch and enlargement, and emphasize the need to
include the invariant line in the definition of stretch. To remove confusion around the effect
of “–” sign, more practice and spiral testing of this knowledge could be done to constantly
remind learners of that property. Lastly, teachers should find out how to use smartphones,
i-phones, i-pods, tablets and other technological devices for teaching and learning, and
utilize them fully to their own and the learners’ advantage in learning these and other
concepts and skills / Mathematics Education / D.Phil. (Mathematics, Science and Technology Education)
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Learning about and understanding fractions and their role in the high school curriculumPienaar, Etienne 04 1900 (has links)
Thesis (MEd)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Many learners, even at high school level, have difficulty with fractions and computations involving fractions. A report from the Department of Basic Education (DBE, 2012c: 15) has highlighted that the lack in basic fraction sense was one of the areas of concern that contributed to the low achievement in matriculation mathematics examinations in 2012. Fractions play an important role in our ever-advancing technological society. Many occupations today rely heavily on the ability to compute accurately, proficiently, and insightfully with fractions. High school learners’ understanding or the lack thereof is carried over to their tertiary studies and workplaces. It is for that reason that in this dissertation, the learning and understanding of fractions and their role in the high school curriculum are studied through a critical literature review. Fractions are compound constructs and can therefore be interpreted in many different ways, depending on the area of study within mathematics. The concept of fractions consists of five sub-constructs, namely, part-whole, ratio, operator, quotient, and measure (Behr, Lesh, Post, & Silver, 1983; Kieren, 1980). This thesis starts with discussion of the background of the study and its importance. Thereafter the elements that assist in the understanding of the fraction concept is discussed. Then, the five different sub-constructs are elaborated on, and how these different sub-constructs are used in the high school curriculum is demonstrated. The conclusion offers some implications for classroom teaching and mathematics teachers’ professional development. / AFRIKAANSE OPSOMMING: Talle leerders, tot op hoërskool vlak, ervaar probleme met breuke en berekeninge met breuke nie. ‘n Verslag van die Departement van Basiese Onderwys (DBE, 2012c: 15) het beklemtoon dat die gebrek aan basiese breuk vaardighede een van die oorsake was wat daartoe gely het dat die prestasie in die 2012 matriek wiskunde eksamen so laag was. Breuke speel ‘n belangrike rol in ons voortdurende tegnologiese voor uitgaande samelewing. Talle beroepe vandag is grootliks afhanklik van die akkurate, bekwame en insiggewende berekeninge van breuke. Hoërskool leerders se begrip, of die gebrek daaraan word oorgedra na hul tersiêre studies en werksplekke. Dit is vir dié rede dat hierdie tesis die leer en begrip van breuke en hul rol in die hoërskool kurrikulum bestudeer deur middel van ‘n kritiese literatuur studie. Breuke is ‘n saamgestelde konsep en kan vir hierdie rede op verskillende wyses geïnterpreteer word, afhangende van die area van studie in wiskunde. Die konsep van ‘n breuk bestaan uit vyf sub-konstrukte, naamlik deel-van-‘n-geheel, ‘n verhouding, operateur, kwosiënt en meting (Behr, Lesh, Post, & Silver, 1983; Kieren, 1980). Hierdie tesis begin met ‘n bespreking oor die agtergrond van hierdie studie en die belangrikheid daarvan. Daarna word die faktore wat bydra tot die verstaan van die breuk konsep. Dit word gevolg deur ‘n uitbreiding op die vyf verskillende sub-konstrukte en waar hierdie verskillende sub-konstrukte in die hoërskool kurrikulum voorkom. Die bevinding bied ‘n paar implikasies vir onderrig. Hierdie studie fokus nie op die ontwerp van enige take of ander leermateriaal vir ‘n intervensie program nie, maar konsentreer op die belangrike kwessies rondom breuke. My hoop is dat die bevindinge van hierdie studie implikasies inhou vir wiskunde onderwysers se professionele ontwikkeling deur hul te motiveer om nuwe leerondersteuningsmateriaal te ontwikkel en die aanbieding van breuke in klaskamers aan te pas sodat die begrip van breuke by leerders ten volle ontwikkel kan word.
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Grade 11 mathematics learner's concept images and mathematical reasoning on transformations of functionsMukono, Shadrick 02 1900 (has links)
The study constituted an investigation for concept images and mathematical reasoning of
Grade 11 learners on the concepts of reflection, translation and stretch of functions. The
aim was to gain awareness of any conceptions that learners have about these
transformations. The researcher’s experience in high school and university mathematics
teaching had laid a basis to establish the research problem.
The subjects of the study were 96 Grade 11 mathematics learners from three conveniently
sampled South African high schools. The non-return of consent forms by some learners
and absenteeism during the days of writing by other learners, resulted in the subsequent
reduction of the amount of respondents below the anticipated 100. The preliminary
investigation, which had 30 learners, was successful in validating instruments and
projecting how the main results would be like. A mixed method exploratory design was
employed for the study, for it was to give in-depth results after combining two data
collection methods; a written diagnostic test and recorded follow-up interviews. All the 96
participants wrote the test and 14 of them were interviewed.
It was found that learners’ reasoning was more based on their concept images than on
formal definitions. The most interesting were verbal concept images, some of which were
very accurate, others incomplete and yet others exhibited misconceptions. There were a lot of inconsistencies in the students’ constructed definitions and incompetency in using
graphical and symbolical representations of reflection, translation and stretch of functions.
For example, some learners were misled by negative sign on a horizontal translation to the right to think that it was a horizontal translation to the left. Others mistook stretch for
enlargement both verbally and contextually.
The research recommends that teachers should use more than one method when teaching
transformations of functions, e.g., practically-oriented and process-oriented instructions,
with practical examples, to improve the images of the concepts that learners develop.
Within their methodologies, teachers should make concerted effort to be aware of the
diversity of ways in which their learners think of the actions and processes of reflecting,
translating and stretching, the terms they use to describe them, and how they compare the
original objects to images after transformations. They should build upon incomplete
definitions, misconceptions and other inconsistencies to facilitate development of accurate
conceptions more schematically connected to the empirical world. There is also a need for
accurate assessments of successes and shortcomings that learners display in the quest to
define and master mathematical concepts but taking cognisance of their limitations of
language proficiency in English, which is not their first language. Teachers need to draw a
clear line between the properties of stretch and enlargement, and emphasize the need to
include the invariant line in the definition of stretch. To remove confusion around the effect
of “–” sign, more practice and spiral testing of this knowledge could be done to constantly
remind learners of that property. Lastly, teachers should find out how to use smartphones,
i-phones, i-pods, tablets and other technological devices for teaching and learning, and
utilize them fully to their own and the learners’ advantage in learning these and other
concepts and skills / Mathematics Education / D.Phil. (Mathematics, Science and Technology Education)
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Lifelong learning of concepts in CRAFTVasishta, Nithin Venkatesh 08 1900 (has links)
La planification à des niveaux d’abstraction plus élevés est essentielle lorsqu’il s’agit de
résoudre des tâches à long horizon avec des complexités hiérarchiques. Pour planifier avec
succès à un niveau d’abstraction donné, un agent doit comprendre le fonctionnement de
l’environnement à ce niveau particulier. Cette compréhension peut être implicite en termes de
politiques, de fonctions de valeur et de modèles, ou elle peut être définie explicitement. Dans
ce travail, nous introduisons les concepts comme un moyen de représenter et d’accumuler
explicitement des informations sur l’environnement.
Les concepts sont définis en termes de transition d’état et des conditions requises pour
que cette transition ait lieu. La simplicité de cette définition offre flexibilité et contrôle
sur le processus d’apprentissage. Étant donné que les concepts sont de nature hautement
interprétable, il est facile d’encoder les connaissances antérieures et d’intervenir au cours
du processus d’apprentissage si nécessaire. Cette définition facilite également le transfert
de concepts entre différents domaines. Les concepts, à un niveau d’abstraction donné, sont
intimement liés aux compétences, ou actions temporellement abstraites. Toutes les transitions
d’état suffisamment importantes pour être représentées par un concept se produisent après
l’exécution réussie d’une compétence. En exploitant cette relation, nous introduisons un
cadre qui facilite l’apprentissage tout au long de la vie et le raffinement des concepts à
différents niveaux d’abstraction. Le cadre comporte trois volets:
Le sytème 1 segmente un flux d’expérience (par exemple une démonstration) en
une séquence de compétences. Cette segmentation peut se faire à différents niveaux
d’abstraction.
Le sytème 2 analyse ces segments pour affiner et mettre à niveau son ensemble de
concepts, lorsqu’applicable.
Le sytème 3 utilise les concepts disponibles pour générer un graphe de dépendance de
sous-tâches. Ce graphe peut être utilisé pour planifier à différents niveaux d’abstraction.
Nous démontrons l’applicabilité de ce cadre dans l’environnement hiérarchique 2D CRAFT. Nous effectuons des expériences pour explorer comment les concepts peuvent être appris
de différents flux d’expérience et comment la qualité de la base de concepts affecte l’optimalité
du plan général. Dans les tâches avec des dépendances de sous-tâches complexes, où
la plupart des algorithmes ne parviennent pas à se généraliser ou prennent un temps impraticable
à converger, nous démontrons que les concepts peuvent être utilisés pour simplifier
considérablement la planification. Ce cadre peut également être utilisé pour comprendre
l’intention d’une démonstration donnée en termes de concepts. Cela permet à l’agent de
répliquer facilement la démonstration dans différents environnements. Nous montrons que
cette méthode d’imitation est beaucoup plus robuste aux changements de configuration de
l’environnement que les méthodes traditionnelles. Dans notre formulation du problème, nous
faisons deux hypothèses: 1) que nous avons accès à un ensemble de compétences suffisamment
exhaustif, et 2) que notre agent a accès à des environnements de pratique, qui peuvent
être utilisés pour affiner les concepts en cas de besoin. L’objectif de ce travail est d’explorer
l’aspect pratique des concepts d’apprentissage comme moyen d’améliorer la compréhension
de l’environnement. Dans l’ensemble, nous démontrons que les concepts d’apprentissage / Planning at higher levels of abstraction is critical when it comes to solving long horizon tasks with hierarchical complexities. To plan successfully at a given level of abstraction, an agent must have an understanding of how the environment functions at that particular level. This understanding may be implicit in terms of policies, value functions, and world models, or it can be defined explicitly. In this work, we introduce concepts as a means to explicitly represent and accumulate information about the environment. Concepts are defined in terms of a state transition and the conditions required for that transition to take place. The simplicity of this definition offers flexibility and control over the learning process. Since concepts are highly interpretable in nature, it is easy to encode prior knowledge and intervene during the learning process if necessary. This definition also makes it relatively straightforward to transfer concepts across different domains wherever applicable. Concepts, at a given level of abstraction, are intricately linked to skills, or temporally abstracted actions. All the state transitions significant enough to be represented by a concept occur only after the successful execution of a skill. Exploiting this relationship, we introduce a framework that aids in lifelong learning and refining of concepts across different levels of abstraction. The framework has three components: - System 1 segments a stream of experience (e.g. a demonstration) into a sequence of skills. This segmentation can be done at different levels of abstraction. - System 2 analyses these segments to refine and upgrade its set of concepts, whenever applicable. - System 3 utilises the available concepts to generate a sub-task dependency graph. This graph can be used for planning at different levels of abstraction We demonstrate the applicability of this framework in the 2D hierarchical environment CRAFT. We perform experiments to explore how concepts can be learned from different streams of experience, and how the quality of the concept base affects the optimality of the overall plan. In tasks with complex sub-task dependencies, where most algorithms fail to generalise or take an impractical amount of time to converge, we demonstrate that concepts can be used to significantly simplify planning. This framework can also be used to understand the intention of a given demonstration in terms of concepts. This makes it easy for the agent to replicate a demonstration in different environments. We show that this method of imitation is much more robust to changes in the environment configurations than traditional methods. In our problem formulation, we make two assumptions: 1) that we have access to a sufficiently exhaustive set of skills, and 2) that our agent has access to practice environments, which can be used to refine concepts when needed. The objective behind this work is to explore the practicality of learning concepts as a means to improve one’s understanding about the environment. Overall, we demonstrate that learning concepts can be a light-weight yet efficient way to increase the capability of a system.
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