Η προσασρμοστική μάθηση (adaptive learning) είναι μια εκπαιδευτική μέθοδος η οποία χρησιμοποιεί κάποιο υπολογιστικό σύστημα ως διαδραστική συσκευή διδασκαλίας αναλαμβάνοντας να προσαρμόσει την παρουσίαση του εκπαιδευτικού υλικού σύμφωνα με τις ανάγκες των μαθητών, όπως αυτές προκύπτουν από τις απαντήσεις τους στις ερωτήσεις και τις εργασίες αλλά και γενικότερα παρατηρώντας παραμέτρους της συμπεριφοράς τους στο σύστημα. Η τεχνολογία που υποστηρίζει τη συγκεκριμένη εκπαιδευτική μέθοδο περιλαμβάνει τις πτυχές που προέρχονται από διάφορους επιστημονικούς τομείς όπως η επιστήμη των υπολογιστών, η εκπαίδευση και η ψυχολογία. Η προσαρμοστικής μάθηση έχει οδηγηθεί εν μέρει από τη συνειδητοποίηση ότι προσωπική μάθηση δεν μπορεί να επιτευχθεί σε μια μεγάλη κλίμακα χρησιμοποιώντας παραδοσιακές, μη-προσαρμοστικές προσεγγίσεις. Τα συστήματα προσαρμοστικής μάθησης στοχεύουν στο να μετατρέψουν τον μαθητή από παθητικό δέκτη πληροφοριών σε συνεργαζόμενο και ενεργό μέλος στην εκπαιδευτική διαδικασία. Ενώ μπορεί να υπάρχουν εξαιρέσεις, τα συστήματα προσαρμοστικής μάθησης είναι γενικά χτισμένα με τρία βασικά στοιχεία: ένα μοντέλο εμπειρογνώμονα ή περιεχομένου, ένα μοντέλο μαθητή, και ένα εκπαιδευτικό ή διδασκαλικό μοντέλο. Στα πλαίσια της διπλωματικής αυτής εργασίας μεταπτυχιακής ειδίκευσης αναπτύχθηκε ένα ηλεκτρονικό εκπαιδευτικό παιχνίδι για φορητή συσκευή το οποίο απευθύνεται σε μαθητές επιπέδου δημοτικού σχολείου και υιοθετεί τις αρχές της προσαρμοστικής μάθησης. Στόχος του παιχνιδιού είναι η εξάσκηση και η σταδιακή βελτίωση εκμάθησης της προπαίδειας. Το εκπαιδευτικό παιχνίδι υλοποιήθηκε σε LUA (Corona SDK) και δοκιμάστηκε σε Android συσκευές. Για να καθοριστούν οι λειτουργικές προδιαγραφές διερευνήθηκαν και καταγράφηκαν ήδη υπάρχοντα αντίστοιχα εκπαιδευτικά παιχνίδια, πραγματοποιήθηκε συνέντευξη με έμπειρη εκπαιδευτικό ώστε να προσαρμοστεί ο σχεδιασμός του σεναρίου του παιχνιδιού στην εκπαιδευτική πρακτική που εφαρμόζεται στο σχολείο, ενώ αφού ολοκληρώθηκε η υλοποίηση πραγματοποιήθηκαν δοκιμές με μαθητές α’, β’, γ’ δημοτικού ώστε να διερευνηθεί η αποτελεσματικότητα του εκπαιδευτικού παιχνιδιού. / Adaptive learning is an educational method that uses a computer system as an interactive teaching apparatus undertaking to adjust the presentation of educational material according to the needs of students, as reflected by their answers to the questions and work well generally observing aspects of their behavior in the system. The technology that supports this educational method includes aspects from different disciplines such as computer science, education and psychology. Adaptive learning has been driven in part by the realization that personal learning can not be achieved on a large scale using traditional non-adaptive approaches. Adaptive learning systems aim to transform the student from passive recipient of information at a partner and active member in the educational process. While there may be exceptions, adaptive learning systems are generally built with three key elements: a model expert or content, a user model, and an educational teaching model. As part of this thesis postgraduate specialization developed an online educational game for mobile device which is aimed at primary school level students and adopts the principles of adaptive learning. The objective of the game is to practice and the gradual improvement of learning the multiplication tables. The educational game implemented in LUA (Corona SDK) and tested on Android devices. To determine the functional specifications were investigated and recorded existing respective educational games, interviewed by experienced teacher to fit the design of the scenario of the game in the educational practice at school, and after the completed implementation was tested with students a, b, c grade to investigate the effectiveness of educational game.

The intergenerational continuity of knowledge has become a concern as small-scale societies worldwide balance the challenges of adapting to environmental change associated with globalization while retaining continuity in their ways of life. This dissertation examines the intergenerational continuity of environmental knowledge through the conceptual lens of an Ethnoecology of Practice framework (EofP) developed to guide this research. Integrating insights from political ecology, social wellbeing and adaptive learning, the EofP provides theoretical and methodological tools based on practice theory to examine the knowledge of small-scale societies. Based on fieldwork in the community of Ponta Negra (Atlantic Forest Coast, Brazil), this dissertation uses a qualitative case study strategy of inquiry guided by a phenomenological worldview. Methods included participant observation, semi-structured interviews covering livelihoods, life histories and marine and terrestrial knowledge themes, document review and a census. Chapters 4 and 5 examine the perception of marine and terrestrial natural resources by tracing their social life from harvesting grounds to exchange and consumption sites. Chapters 6 and 9 analyse historical and contemporary adaptation to environmental change. While Chapter 6 describes the adoption of the pound net fishery, Chapter 9 illustrates contemporary modes of learning associated with natural resource harvesting and presents the processes associated with production of new knowledge through the example of local participation in the tourism economy. Chapter 7 examines local perspectives on livelihood transition from a social wellbeing perspective and highlights factors underlying the continuity of natural resource harvesting practice in Ponta Negra. Chapter 8 discusses how the term Caiçara, as used in biodiversity conservation and tourism development discourses, circumscribes the relation between coastal people and their local environments to a subsistence economy, denying their current economic engagements as well as their desires and aspirations. This dissertation contributes to ethnobiological understandings of the intergenerational continuity of knowledge by providing a framework and grounding evidence that demonstrates how knowledge is generated through context-specific practice attuned to dynamic environments that leads to individual innovation. It provides a theoretical contribution to our understanding of framing and creating processes inherent to human-in environment relations that lead to fluidity in ways of life over time.

This study investigated personalized adaptive learning, teacher education, and self-efficacy to determine if personalized adaptive teacher education can increase self-efficacy. It is suggested that teachers with higher self-efficacy tend to stay in the teaching profession longer. Chapters 2 and 3 are literature reviews on personalizing adaptive learning to determine what common components are used in personalized adaptive learning systems to get a clear understanding of what previous literature suggests building this study on it. Chapter 4 investigates the data collected from 385 teachers to understand better what teachers report on factors that increase their self-efficacy. As a result, it was found that teachers' self-efficacy increases with more training, support, and resources. In chapter 5, a framework was developed based on previous findings, with components of personalized adaptive learning to provide support/help at the right time for teachers to increase their self-efficacy. An empirical study was conducted to validate this framework, where the framework was used as a guide to personalize and adapt summer teacher preservice training and survey teachers on their self-efficacy before and after the training to see its impact on teachers' self-efficacy. However, since summer preservice training was virtual, the framework could not be implemented fully, as we were not able to observe teachers' behaviors and monitor their learning to provide them help and support, as needed and being in the post-COVID-19 year as educators dealing with about two-year learning loss systemwide, seems decreased teachers' self-efficacy. The findings of this study can guide preservice teacher education institutions and decision-makers of teacher education to assess inservice teachers' needs and self-efficacy to help and support them with a more personalized adaptive education to improve their self-efficacy.

x, 132 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This dissertation examines the role that institutions play in the existence of multiple equilibria in models of economic development. In addition, it examines the dynamics of transition between such equilibria. In the first chapter of this dissertation, I build a dynamic model of institutional choice, wherein the government invests in the legal infrastructure in response to the need for the protection of output from appropriation. A unique equilibrium exists only under commitment, not under discretion. This would suggest that a measure of institutional quality must not only consider the extent to which current policies protect property rights but also include the ability of the government to commit to reform in the long run. The second chapter of this dissertation examines the effect of adaptive learning on stability and transitional dynamics between multiple equilibria in a growth model with human capital externalities. I find that there are two equilibria, one a poverty trap with no education. Only the poverty trap is locally stable under learning. However, productivity shocks are not sufficient to generate transitions between the equilibria. Indeed, productivity shocks must lie below a threshold in order for the economy to escape the poverty trap. These escape paths do not allow the economy to transition to the upper steady state. I propose instead the use of shocks to expectations to permit such a transition. The third chapter of this dissertation presents an empirical test for the role that human capital and institutions may play in transitions between equilibria by estimating a Markov-switching regression. This methodology allows me to characterize both distinct growth regimes and transitions between them. I explore the effects of time-varying institutional measures and human capital on transition probabilities. I find that political and economic institutions are similar in their effects on transitions arid that the time variation in the institutional measure increases the probability of identifying both miracle growth and stagnation regimes. Furthermore, human capital has a significant effect on switches between miracle growth, stable growth and stagnation. / Committee in charge: George Evans, Co-Chairperson, Economics; Shankha Chakraborty, Co-Chairperson, Economics; Jeremy Piger, Member, Economics; Yue Fang, Outside Member, Decision Sciences

xi, 87 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The behavior of the macroeconomy and monetary policy is heavily influenced by expectations. Recent research has explored how minor changes in expectation formation can change the stability properties of a model. One common way to alter expectation formation involves agents' use of econometrics to form forecasting equations. Agents update their forecasts based on new information that arises as the economy progresses through time. In this way agents "learn" about the economy. Previous learning literature mostly focuses on agents using a fixed data size or increasing the amount of data they use. My research explores how agents might endogenously change the amount of data they use to update their forecast equations. My first chapter explores how an established endogenous learning algorithm, proposed by Marcet and Nicolini, may influence monetary policy decisions. Under rational expectations (RE) determinacy serves as the main criterion for favoring a model or monetary policy rule. A determinant model need not result in stability under an alternative expectation formation process called learning. Researchers appeal to stability under learning as a criterion for monetary policy rule selection. This chapter provides a cautionary tale for policy makers and reinforces the importance of the role of expectations. Simulations appear stable for a prolonged interval of time but may suddenly deviate from the RE solution. This exotic behavior exhibits significantly higher volatility relative to RE yet over long simulations remains true to the RE equilibrium. In the second chapter I address the effectiveness of endogenous gain learning algorithms in the presence of occasional structural breaks. Marcet and Nicolini's algorithm relies on agents reacting to forecast errors. I propose an alternative, which relies on agents using statistical information. The third chapter uses standard macroeconomic data to find out whether a model that has non-rational expectations can outperform RE. I answer this question affirmatively and explore what learning means to the economy. In addition, I conduct a Monte Carlo exercise to investigate whether a simple learning model does, empirically, imbed an RE model. While theoretically a very small constant gain implies RE, empirically learning creates bias in coefficient estimates. / Committee in charge: George Evans, Co-Chairperson, Economics; Jeremy Piger, Co-Chairperson, Economics; Shankha Chakraborty, Member, Economics; Sergio Koreisha, Outside Member, Decision Sciences

In this dissertation I incorporate high dimensional data vectors in estimated Dynamic Stochastic General Equilibrium (DSGE) models, evaluating the labor market dynamics incorporated inside such data vectors, out-of-sample forecasting performance of many models estimated with such data vectors and analytically examining the reduction of macroeconomic volatility that can occur when such data vectors are used in the formation of expectations about the future. The second chapter investigates the extent to which modern DSGE models can produce labor market dynamics in response to a financial crisis that are consistent with the experience of the Great Recession. I estimate two New-Keynesian models, one with and one without financial frictions, in a data-rich environment. I find that negative financial shocks are associated with longer recoveries in real investment, capital-intensive sectors of the labor market and average unemployment duration. I also find the model with a financial accelerator is equipped with better tools to identify the dynamics associated with the Great Recession and its recovery in regard to many labor and financial metrics. The third chapter compares the out-of-sample forecasting performance of the two DSGE models of Chapter II when they are estimated both out of and in a data-rich environment. This chapter finds that many financial time series variance decomposition are significantly better explained using the structural set-up of the New-Keynesian model with financial frictions. DSGE models estimated with high dimensional data vectors significantly out forecast their regularly estimated counterpart in regard to output, investment and consumption growth. Lastly, the use of real-time optimal pool model weighting significantly out-forecasts traditional macroeconomic models as well as an equally weighted weighting scheme in terms of many macroeconomic variables. The fourth chapter examines the role forecasts derived by high dimensional data vectors can have on lowering macroeconomic volatility. Bounded rational agents are introduced into the Chapter II DSGE model with financial frictions and are given the option to use or ignore professionally generated forecasts from a dynamic factor model in their perceived forecasting model. In simulations, I find that professionally generated forecasts can significantly lower the volatility of many macroeconomic variables including inflation and hours worked.

This dissertation studies the impact embedding boundedly rational agents in real business cycle-type news-shock models may have on a variety of model predictions, from simulated moments to structural parameter estimates. In particular, I analyze the qualitative and quantitative effects of assuming agents are boundedly rational in a class of DSGE models which attempt to explain the observed volatility and comovements in key aggregate measures of U.S. economic performance as the result of endogenous responses to information in the form of ``news shocks''. The first chapter explores the theoretical feasibility of relaxing the rational expectations hypothesis in a three-sector real business cycle (RBC) model which generates boom-bust cycles as a result of periods of optimism and pessimism on the part of households. The second chapter determines whether agents forming linear forecasts of shadow prices in a nonlinear framework can lead to behavior approximately consistent with fully informed individuals in a one-sector real business cycle model. The third chapter analyzes whether empirical estimates of the relative importance of anticipated shocks may be biased by assuming rational expectations. By merging the two hitherto separate but complementary strands of literature related to bounded rationality and news shocks I am able to conduct in-depth analysis of the importance of both the information agents have and what they choose to do with it. At its core, the study of news in macroeconomics is a study of the specific role alternative information sets play in generating macroeconomic volatility. Adaptive learning on the other hand is concerned with the behavior of agents given an information set. Taken together, these fields jointly describe the input and the ``black box'' which produce model predictions from DSGE models. While previous research has been conducted on the effects of bounded rationality or news shocks in isolation, this dissertation marks the first set of research explicitly focused on the interaction of these two model features.

Será que os estudantes de hoje têm habilidades para alternar o foco, dividindo seu tempo de estudo entre duas ou mais “fontes didáticas” às quais são expostos? Nesta tese se entende por “fonte didática” toda fonte de comunicação que pode passar informações através de pessoas ou máquinas, com intuito de ensinar um conceito. Assim, pesquisou-se através de experimentos em que os estudantes eram expostos às diferentes “fontes didáticas”, sendo medidos seus desempenhos por meio de testes como forma de entender suas capacidades de aprendizagem. As TICs têm possibilitado o acesso em simultâneo a várias “fontes didáticas” por um mesmo estudante ao mesmo tempo. Embora este acesso possa ocasionar um excesso de estímulos aos aprendizes, é preciso, então, pesquisar as consequências no processo de aprendizagem: um discente que está assistindo, por exemplo, a uma aula de um bom professor e, ao mesmo tempo, através de seu celular, consulta outras fontes didáticas disponíveis, ou simplesmente decide assistir dois objetos de aprendizagem ao mesmo tempo, sendo um interativo e outro visual, ou um visual e auditivo. Esta forma de estudo é, todavia, benéfica para seu processo de aprendizagem? É justamente na busca de respostas a estas perguntas que a presente tese de doutorado investigou a forma de navegação de estudantes quando expostos a duas apresentações paralelas multimídias e multimodais, considerando o conceito de trajetórias de aprendizagem em função dos tempos de estudo envolvidos. Este estudo tem como base teórica o construtivismo e o interacionismo de Piaget, neste contexto de exploração paralela ou alternada de vários objetos de aprendizagem. A pesquisa teve natureza explicativa, abordagem quantitativa e modalidade quase-experimental. Foi desenvolvido um sistema capaz de apresentar, ao mesmo tempo, dois objetos de aprendizagem para um mesmo estudante, e de monitorar a navegação desse aprendiz. O sistema desenvolvido no âmbito dessa tese foi denominado Apresentações Adaptativas Multimídias e Multimodais (AAMM), e foi implementado em HTML, PHP, AJAX e JavaScript. Nessa pesquisa foi avaliado o desempenho dos estudantes através de dois testes diferentes (pré-teste e pós-teste), mas com os mesmos níveis de dificuldade (um antes e outro após a exploração dos objetos de aprendizagem interativos e não interativos). Após o desenvolvimento do sistema AAMM e a realização do estudo piloto apresentado na proposta da tese, foram realizados dois experimentos com o objetivo de investigar a forma de navegação dos estudantes face a duas ou mais apresentações paralelas multimídia, considerando os estilos de aprendizagem preferenciais. Foram realizados testes estatísticos de Wilcoxon e Kruskal-Wallis, e os resultados das análises mostraram evidências para afirmar que em apresentações adaptativas multimídia compostas por objetos de aprendizagem interativos e não interativos é recomendável que se priorize os objetos de aprendizagem interativos seguidos dos não interativos; estudantes que efetuam múltiplas transições entre os materiais didáticos apresentam mau rendimento; o tempo que os estudantes levam a interagir com um objeto de aprendizagem não influencia no seu aproveitamento final, mas, quanto maior o tempo de dedicação aos objetos de aprendizagem interativos maior a probabilidade de se obter bom aproveitamento nos processos de ensino e aprendizagem. / Do students today have the ability to shift focus by dividing their study time between two or more didactic sources to which they are exposed? In this thesis is meant by "didactic source" all source of communication that can pass information through people or machines, in order to teach a concept. Thus, we investigated through experiments in which students were exposed to different "didactic sources", being measured their performances through tests as a way of understanding their learning abilities. ICTs have enabled simultaneous access to several didactic resources by the same student at the same time. Although this access may lead to an excess of stimuli for learners, it is necessary to investigate the consequences in the learning process: a student who is watching, for example, a lesson of a good teacher and, at the same time, through his Cell phone, consult other educational resources available, or simply decide to watch two learning objects at once, being an interactive and another visual, or a visual and auditory. Is this form of study, however, beneficial to his learning process? It is precisely in the search for answers to these questions that the present thesis investigated the way students navigate when exposed to two multimodal and multimodal parallel presentations, considering the concept of learning trajectories according to the study times involved. This study is based on Piaget’s constructivism and interactionism, in this context of a parallel or alternating exploration of several learning objects. The research had explanatory nature, quantitative approach, and quasi-experimental modality. A system was developed capable of presenting at the same time two learning objects for the same student, and of monitoring the navigation of this learner. The system developed under this thesis was called Multimedia and Multimodal Adaptive Presentations (AAMM), and was implemented in HTML, PHP, AJAX and JavaScript. In this research, students' performance was evaluated through two different tests (pre-test and post-test), but with the same levels of difficulty (one before and one after the exploration of interactive and non-interactive learning objects). After the development of the AAMM system and the pilot study presented in the thesis proposal, two experiments were carried out to investigate the way students navigate two or more parallel multimedia presentations, considering the preferred learning styles. Wilcoxon and Kruskal-Wallis statistical tests were performed, and The results of the analyses showed evidence to affirm that in multimedia adaptive presentations composed of interactive and noninteractive learning objects it is recommended that prioritized interactive learning objects followed by non-interactive ones; Students who carry out multiple transitions between didactic materials present poor performance; The time that students take to interact with a learning object does not influence their final achievement, but the longer the time of dedication to interactive learning objects the greater the likelihood of successful achievement in the learning process.

abstract: Science instructors need questions for use in exams, homework assignments, class discussions, reviews, and other instructional activities. Textbooks never have enough questions, so instructors must find them from other sources or generate their own questions. In order to supply instructors with biology questions, a semantic network approach was developed for generating open response biology questions. The generated questions were compared to professional authorized questions. To boost students’ learning experience, adaptive selection was built on the generated questions. Bayesian Knowledge Tracing was used as embedded assessment of the student’s current competence so that a suitable question could be selected based on the student’s previous performance. A between-subjects experiment with 42 participants was performed, where half of the participants studied with adaptive selected questions and the rest studied with mal-adaptive order of questions. Both groups significantly improved their test scores, and the participants in adaptive group registered larger learning gains than participants in the control group. To explore the possibility of generating rich instructional feedback for machine-generated questions, a question-paragraph mapping task was identified. Given a set of questions and a list of paragraphs for a textbook, the goal of the task was to map the related paragraphs to each question. An algorithm was developed whose performance was comparable to human annotators. A multiple-choice question with high quality distractors (incorrect answers) can be pedagogically valuable as well as being much easier to grade than open-response questions. Thus, an algorithm was developed to generate good distractors for multiple-choice questions. The machine-generated multiple-choice questions were compared to human-generated questions in terms of three measures: question difficulty, question discrimination and distractor usefulness. By recruiting 200 participants from Amazon Mechanical Turk, it turned out that the two types of questions performed very closely on all the three measures. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2015

Será que os estudantes de hoje têm habilidades para alternar o foco, dividindo seu tempo de estudo entre duas ou mais “fontes didáticas” às quais são expostos? Nesta tese se entende por “fonte didática” toda fonte de comunicação que pode passar informações através de pessoas ou máquinas, com intuito de ensinar um conceito. Assim, pesquisou-se através de experimentos em que os estudantes eram expostos às diferentes “fontes didáticas”, sendo medidos seus desempenhos por meio de testes como forma de entender suas capacidades de aprendizagem. As TICs têm possibilitado o acesso em simultâneo a várias “fontes didáticas” por um mesmo estudante ao mesmo tempo. Embora este acesso possa ocasionar um excesso de estímulos aos aprendizes, é preciso, então, pesquisar as consequências no processo de aprendizagem: um discente que está assistindo, por exemplo, a uma aula de um bom professor e, ao mesmo tempo, através de seu celular, consulta outras fontes didáticas disponíveis, ou simplesmente decide assistir dois objetos de aprendizagem ao mesmo tempo, sendo um interativo e outro visual, ou um visual e auditivo. Esta forma de estudo é, todavia, benéfica para seu processo de aprendizagem? É justamente na busca de respostas a estas perguntas que a presente tese de doutorado investigou a forma de navegação de estudantes quando expostos a duas apresentações paralelas multimídias e multimodais, considerando o conceito de trajetórias de aprendizagem em função dos tempos de estudo envolvidos. Este estudo tem como base teórica o construtivismo e o interacionismo de Piaget, neste contexto de exploração paralela ou alternada de vários objetos de aprendizagem. A pesquisa teve natureza explicativa, abordagem quantitativa e modalidade quase-experimental. Foi desenvolvido um sistema capaz de apresentar, ao mesmo tempo, dois objetos de aprendizagem para um mesmo estudante, e de monitorar a navegação desse aprendiz. O sistema desenvolvido no âmbito dessa tese foi denominado Apresentações Adaptativas Multimídias e Multimodais (AAMM), e foi implementado em HTML, PHP, AJAX e JavaScript. Nessa pesquisa foi avaliado o desempenho dos estudantes através de dois testes diferentes (pré-teste e pós-teste), mas com os mesmos níveis de dificuldade (um antes e outro após a exploração dos objetos de aprendizagem interativos e não interativos). Após o desenvolvimento do sistema AAMM e a realização do estudo piloto apresentado na proposta da tese, foram realizados dois experimentos com o objetivo de investigar a forma de navegação dos estudantes face a duas ou mais apresentações paralelas multimídia, considerando os estilos de aprendizagem preferenciais. Foram realizados testes estatísticos de Wilcoxon e Kruskal-Wallis, e os resultados das análises mostraram evidências para afirmar que em apresentações adaptativas multimídia compostas por objetos de aprendizagem interativos e não interativos é recomendável que se priorize os objetos de aprendizagem interativos seguidos dos não interativos; estudantes que efetuam múltiplas transições entre os materiais didáticos apresentam mau rendimento; o tempo que os estudantes levam a interagir com um objeto de aprendizagem não influencia no seu aproveitamento final, mas, quanto maior o tempo de dedicação aos objetos de aprendizagem interativos maior a probabilidade de se obter bom aproveitamento nos processos de ensino e aprendizagem. / Do students today have the ability to shift focus by dividing their study time between two or more didactic sources to which they are exposed? In this thesis is meant by "didactic source" all source of communication that can pass information through people or machines, in order to teach a concept. Thus, we investigated through experiments in which students were exposed to different "didactic sources", being measured their performances through tests as a way of understanding their learning abilities. ICTs have enabled simultaneous access to several didactic resources by the same student at the same time. Although this access may lead to an excess of stimuli for learners, it is necessary to investigate the consequences in the learning process: a student who is watching, for example, a lesson of a good teacher and, at the same time, through his Cell phone, consult other educational resources available, or simply decide to watch two learning objects at once, being an interactive and another visual, or a visual and auditory. Is this form of study, however, beneficial to his learning process? It is precisely in the search for answers to these questions that the present thesis investigated the way students navigate when exposed to two multimodal and multimodal parallel presentations, considering the concept of learning trajectories according to the study times involved. This study is based on Piaget’s constructivism and interactionism, in this context of a parallel or alternating exploration of several learning objects. The research had explanatory nature, quantitative approach, and quasi-experimental modality. A system was developed capable of presenting at the same time two learning objects for the same student, and of monitoring the navigation of this learner. The system developed under this thesis was called Multimedia and Multimodal Adaptive Presentations (AAMM), and was implemented in HTML, PHP, AJAX and JavaScript. In this research, students' performance was evaluated through two different tests (pre-test and post-test), but with the same levels of difficulty (one before and one after the exploration of interactive and non-interactive learning objects). After the development of the AAMM system and the pilot study presented in the thesis proposal, two experiments were carried out to investigate the way students navigate two or more parallel multimedia presentations, considering the preferred learning styles. Wilcoxon and Kruskal-Wallis statistical tests were performed, and The results of the analyses showed evidence to affirm that in multimedia adaptive presentations composed of interactive and noninteractive learning objects it is recommended that prioritized interactive learning objects followed by non-interactive ones; Students who carry out multiple transitions between didactic materials present poor performance; The time that students take to interact with a learning object does not influence their final achievement, but the longer the time of dedication to interactive learning objects the greater the likelihood of successful achievement in the learning process.