La détection d'anomalies comme outil de renforcement d'analyse des données et de prédiction dans l'éducation

Les établissements d'enseignement cherchent à concevoir des mécanismes efficaces pour améliorer les résultats scolaires, renforcer le processus d'apprentissage et éviter l'abandon scolaire. L'analyse et la prédiction des performances des étudiants au cours de leurs études peuvent mettre en évidence certaines lacunes d'une formation et détecter les étudiants ayant des problèmes d'apprentissage. Il s'agit donc de développer des techniques et des modèles basés sur des données qui visent à améliorer l'enseignement et l'apprentissage. Les modèles classiques ignorent généralement les étudiants présentant des comportements et incohérences inhabituels, bien qu'ils puissent fournir des informations importantes aux experts du domaine et améliorer les modèles de prédiction. Les profils atypiques dans l'éducation sont à peine explorés et leur impact sur les modèles de prédiction n'a pas encore été étudié dans la littérature. Cette thèse vise donc à étudier les valeurs anormales dans les données éducatives et à étendre les connaissances existantes à leur sujet. La thèse présente trois études de cas de détection de données anormales pour différents contextes éducatifs et modes de représentation des données (jeu de données numériques pour une université allemande, jeu de données numériques pour une université russe, jeu de données séquentiel pour les écoles d'infirmières françaises). Pour chaque cas, l'approche de prétraitement des données est proposée en tenant compte des particularités du jeu de données. Les données préparées ont été utilisées pour détecter les valeurs anormales dans des conditions de vérité terrain inconnue. Les caractéristiques des valeurs anormales détectées ont été explorées et analysées, ce qui a permis d'étendre les connaissances sur le comportement des étudiants dans un processus d'apprentissage. L'une des principales tâches dans le domaine de l'éducation est de développer des mécanismes essentiels qui permettront d'améliorer les résultats scolaires et de réduire l'abandon scolaire. Ainsi, il est nécessaire de construire des modèles de prédiction de performance qui sont capables de détecter les étudiants ayant des problèmes d'apprentissage, qui ont besoin d'une aide spéciale. Le deuxième objectif de la thèse est d'étudier l'impact des valeurs anormales sur les modèles de prédiction. Nous avons considéré deux des tâches de prédiction les plus courantes dans le domaine de l'éducation: (i) la prédiction de l'abandon scolaire, (ii) la prédiction du score final. Les modèles de prédiction ont été comparés en fonction de différents algorithmes de prédiction et de la présence de valeurs anormales dans les données d'entraînement. Cette thèse ouvre de nouvelles voies pour étudier les performances des élèves dans les environnements éducatifs. La compréhension des valeurs anormales et des raisons de leur apparition peut aider les experts du domaine à extraire des informations précieuses des données. La détection des valeurs aberrantes pourrait faire partie du pipeline des systèmes d'alerte précoce pour détecter les élèves à haut risque d'abandon. De plus, les tendances comportementales des valeurs aberrantes peuvent servir de base pour fournir des recommandations aux étudiants dans leurs études ou prendre des décisions concernant l'amélioration du processus éducatif.Educational institutions seek to design effective mechanisms that improve academic results, enhance the learning process, and avoid dropout. The performance analysis and performance prediction of students in their studies may show drawbacks in the educational formations and detect students with learning problems. This induces the task of developing techniques and data-based models which aim to enhance teaching and learning. Classical models usually ignore the students-outliers with uncommon and inconsistent characteristics although they may show significant information to domain experts and affect the prediction models. The outliers in education are barely explored and their impact on the prediction models has not been studied yet in the literature. Thus, the thesis aims to investigate the outliers in educational data and extend the existing knowledge about them. The thesis presents three case studies of outlier detection for different educational contexts and ways of data representation (numerical dataset for the German University, numerical dataset for the Russian University, sequential dataset for French nurse schools). For each case, the data preprocessing approach is proposed regarding the dataset peculiarities. The prepared data has been used to detect outliers in conditions of unknown ground truth. The characteristics of detected outliers have been explored and analysed, which allowed extending the comprehension of students' behaviour in a learning process. One of the main tasks in the educational domain is to develop essential tools which will help to improve academic results and reduce attrition. Thus, plenty of studies aim to build models of performance prediction which can detect students with learning problems that need special help. The second goal of the thesis is to study the impact of outliers on prediction models. The two most common prediction tasks in the educational field have been considered: (i) dropout prediction, (ii) the final score prediction. The prediction models have been compared in terms of different prediction algorithms and the presence of outliers in the training data. This thesis opens new avenues to investigate the students' performance in educational environments. The understanding of outliers and the reasons for their appearance can help domain experts to extract valuable information from the data. Outlier detection might be a part of the pipeline in the early warning systems of detecting students with a high risk of dropouts. Furthermore, the behavioral tendencies of outliers can serve as a basis for providing recommendations for students in their studies or making decisions about improving the educational process

The role of machine learning in identifying students at-risk and minimizing failure

Education is very important for students' future success. The performance of students can be supported by the extra assignments and projects given by the instructors for students with low performance. However, a major problem is that students at-risk cannot be identified early. This situation is being investigated by various researchers using Machine Learning techniques. Machine learning is used in a variety of areas and has also begun to be used to identify students at-risk early and to provide support by instructors. This research paper discusses the performance results found using Machine learning algorithms to identify at-risk students and minimize student failure. The main purpose of this project is to create a hybrid model using the ensemble stacking method and to predict at-risk students using this model. We used machine learning algorithms such as Naive Bayes, Random Forest, Decision Tree, K-Nearest Neighbors, Support Vector Machine, AdaBoost Classifier and Logistic Regression in this project. The performance of each machine learning algorithm presented in the project was measured with various metrics. Thus, the hybrid model by combining algorithms that give the best prediction results is presented in this study. The data set containing the demographic and academic information of the students was used to train and test the model. In addition, a web application developed for the effective use of the hybrid model and for obtaining prediction results is presented in the report. In the proposed method, it has been realized that stratified k-fold cross validation and hyperparameter optimization techniques increased the performance of the models. The hybrid ensemble model was tested with a combination of two different datasets to understand the importance of the data features. In first combination, the accuracy of the hybrid model was obtained as 94.8% by using both demographic and academic data. In the second combination, when only academic data was used, the accuracy of the hybrid model increased to 98.4%. This study focuses on predicting the performance of at-risk students early. Thus, teachers will be able to provide extra assistance to students with low performance

Assignments as Influential Factor to Improve the Prediction of Student Performance in Online Courses

Studies on the prediction of student success in distance learning have explored mainly demographics factors and student interactions with the virtual learning environments. However, it is remarkable that a very limited number of studies use information about the assignments submitted by students as influential factor to predict their academic achievement. This paper aims to explore the real importance of assignment information for solving students’ performance prediction in distance learning and evaluate the beneficial effect of including this information. We investigate and compare this factor and its potential from two information representation approaches: the traditional representation based on single instances and a more flexible representation based on Multiple Instance Learning (MIL), focus on handle weakly labeled data. A comparative study is carried out using the Open University Learning Analytics dataset, one of the most important public datasets in education provided by one of the greatest online universities of United Kingdom. The study includes a wide set of different types of machine learning algorithms addressed from the two data representation commented, showing that algorithms using only information about assignments with a representation based on MIL can outperform more than 20% the accuracy with respect to a representation based on single instance learning. Thus, it is concluded that applying an appropriate representation that eliminates the sparseness of data allows to show the relevance of a factor, such as the assignments submitted, not widely used to date to predict students’ academic performance. Moreover, a comparison with previous works on the same dataset and problem shows that predictive models based on MIL using only assignments information obtain competitive results compared to previous studies that include other factors to predict students performance

Predicción del rendimiento académico universitario mediante mecanismos de aprendizaje automático y métodos supervisados

Context:  In the education sector, variables have been identified which considerably affect students’ academic performance. In the last decade, research has been carried out from various fields such as psychology, statistics, and data analytics in order to predict academic performance. Method: Data analytics, especially through Machine Learning tools, allows predicting academic performance using supervised learning algorithms based on academic, demographic, and sociodemographic variables. In this work, the most influential variables in the course of students’ academic life are selected through wrapping, embedded, filter, and assembler methods, as well as the most important characteristics semester by semester using Machine Learning algorithms (Decision Trees, KNN, SVC, Naive Bayes, LDA), which were implemented using the Python language. Results: The results of the study show that the KNN is the model that best predicts academic performance for each of the semesters, followed by Decision Trees, with precision values that oscillate around 80 and 78,5% in some semesters. Conclusions: Regarding the variables, it cannot be said that a student’s per-semester academic average necessarily influences the prediction of academic performance for the next semester. The analysis of these results indicates that the prediction of academic performance using Machine Learning tools is a promising approach that can help improve students’ academic life allow institutions and teachers to take actions that contribute to the teaching-learning process.considerablemente en el rendimiento académico de los estudiantes. En la última década se han llevado a cabo investigaciones desde diversos campos como la psicología, la estadística y el análisis de datos con el fin de predecir el rendimiento académico. Método: La analítica de datos, especialmente a través de herramientas de Machine Learning, permite predecir el rendimiento académico utilizando algoritmos de aprendizaje supervisado basados ​​en variables académicas, demográficas y sociodemográficas. En este trabajo se seleccionan las variables más influyentes en el transcurso de la vida académica de los estudiantes mediante métodos de filtro, embebidos, y de ensamble, así como las características más importantes semestre a semestre utilizando algoritmos de Machine Learning (árbol de decisión, KNN, SVC, Naive Bayes, LDA), implementados en el lenguaje Python. Resultados: Los resultados del estudio muestran que el KNN es el modelo que mejor predice el rendimiento académico para cada uno de los semestres, seguido de los árboles de decisión, con valores de precisión que oscilan alrededor del 80 y 78,5 % en algunos semestres. Conclusiones: Con respecto a las variables, no se puede decir que el promedio académico semestral de un estudiante influya necesariamente en la predicción del rendimiento académico del siguiente semestre. El análisis de estos resultados indica que la predicción del rendimiento académico utilizando herramientas de Machine Learning es un enfoque promisorio que puede ayudar a mejorar la vida académica de los estudiantes y permitir a las instituciones y a los docentes adoptar acciones que ayuden al proceso de enseñanza-aprendizaje

IDENTIFICATION OF STUDENTS AT RISK OF LOW PERFORMANCE BY COMBINING RULE-BASED MODELS, ENHANCED MACHINE LEARNING, AND KNOWLEDGE GRAPH TECHNIQUES

Technologies and online learning platforms have changed the contemporary educational paradigm, giving institutions more alternatives in a complex and competitive environment. Online learning platforms, learning-based analytics, and data mining tools are increasingly complementing and replacing traditional education techniques. However, academic underachievement, graduation delays, and student dropouts remain common problems in educational institutions. One potential method of preventing these issues is by predicting student performance through the use of institution data and advanced technologies. However, to date, scholars have yet to develop a module that can accurately predict students’ academic achievement and commitment. This dissertation attempts to bridge that gap by presenting a framework that allows instructors to achieve four goals: (1) track and monitor the performance of each student on their course, (2) identify at-risk students during the earliest stages of the course progression (3), enhance the accuracy with which at-risk student performance is predicted, and (4) improve the accuracy of student ranking and development of personalized learning interventions. These goals are achieved via four objectives. Objective One proposes a rule-based strategy and risk factor flag to warn instructors about at-risk students. Objective Two classifies at-risk students using an explainable ML-based model and rule-based approach. It also offers remedial strategies for at-risk students at each checkpoint to address their weaknesses. Objective Three uses ML-based models, GCNs, and knowledge graphs to enhance the prediction results. Objective Four predicts students’ ranking using ML-based models and clustering-based KGEs with the aim of developing personalized learning interventions. It is anticipated that the solution presented in this dissertation will help educational institutions identify and analyze at-risk students on a course-by-course basis and, thereby, minimize course failure rates

Towards Personalized Learning using Counterfactual Inference for Randomized Controlled Trials

Personalized learning considers that the causal effects of a studied learning intervention may differ for the individual student (e.g., maybe girls do better with video hints while boys do better with text hints). To evaluate a learning intervention inside ASSISTments, we run a randomized control trial (RCT) by randomly assigning students into either a control condition or a treatment condition. Making the inference about causal effects of studies interventions is a central problem. Counterfactual inference answers “What if� questions, such as Would this particular student benefit more if the student were given the video hint instead of the text hint when the student cannot solve a problem? . Counterfactual prediction provides a way to estimate the individual treatment effects and helps us to assign the students to a learning intervention which leads to a better learning. A variant of Michael Jordan\u27s Residual Transfer Networks was proposed for the counterfactual inference. The model first uses feed-forward neural networks to learn a balancing representation of students by minimizing the distance between the distributions of the control and the treated populations, and then adopts a residual block to estimate the individual treatment effect. Students in the RCT usually have done a number of problems prior to participating it. Each student has a sequence of actions (performance sequence). We proposed a pipeline to use the performance sequence to improve the performance of counterfactual inference. Since deep learning has achieved a huge amount of success in learning representations from raw logged data, student representations were learned by applying the sequence autoencoder to performance sequences. Then, incorporate these representations into the model for counterfactual inference. Empirical results showed that the representations learned from the sequence autoencoder improved the performance of counterfactual inference

A Comprehensive Survey of Deep Learning in Remote Sensing: Theories, Tools and Challenges for the Community

In recent years, deep learning (DL), a re-branding of neural networks (NNs), has risen to the top in numerous areas, namely computer vision (CV), speech recognition, natural language processing, etc. Whereas remote sensing (RS) possesses a number of unique challenges, primarily related to sensors and applications, inevitably RS draws from many of the same theories as CV; e.g., statistics, fusion, and machine learning, to name a few. This means that the RS community should be aware of, if not at the leading edge of, of advancements like DL. Herein, we provide the most comprehensive survey of state-of-the-art RS DL research. We also review recent new developments in the DL field that can be used in DL for RS. Namely, we focus on theories, tools and challenges for the RS community. Specifically, we focus on unsolved challenges and opportunities as it relates to (i) inadequate data sets, (ii) human-understandable solutions for modelling physical phenomena, (iii) Big Data, (iv) non-traditional heterogeneous data sources, (v) DL architectures and learning algorithms for spectral, spatial and temporal data, (vi) transfer learning, (vii) an improved theoretical understanding of DL systems, (viii) high barriers to entry, and (ix) training and optimizing the DL.Comment: 64 pages, 411 references. To appear in Journal of Applied Remote Sensin