Carla Limongelli - Academia.edu (original) (raw)
Papers by Carla Limongelli
IEEE Access
The Web offers an unprecedented number of resources and has become the most popular source of inf... more The Web offers an unprecedented number of resources and has become the most popular source of information for students shaping their understanding of a new topic, and for instructors selecting relevant material for learning and teaching activities. Even though search engines are the most widely used tools for searching for educational content, the realities of the learning and teaching processes make the retrieval and evaluation of educational resources more complex than they are for other goods or services. The lack of recourse to educational metadata in web pages, as well as the size of the Web itself, call for specific techniques to be adopted for a more effective ranking of educational content. In this study, we propose an innovative approach based on semantic technologies. The SemanticSearch approach described in this paper leverages knowledge graph representation of teaching contexts and proposes a new ranking method for rating educational web content. In the literature we find an Educational Ranking Principle that ranks web pages for a specific teaching context. In this study, we integrate the Educational Ranking Principle with semantic data to extend the experimentation and analyse performance further. We undertake an evaluation involving university teachers, considering more than 70 queries to measure the SemanticSearch performance against the Educational Ranking Principle in addition to two state-of-the-art methodologies: Tf-Idf and BM25F. Paired t-tests of four accuracy measures provide statistical evidence for improvements made by using SemanticSearch method when compared to the three baselines. INDEX TERMS Semantic-based retrieval, instructional materials, web ranking principles, teacher support.
Although ubiquitous and fast access to the Internet allows us to admire objects and artworks exhi... more Although ubiquitous and fast access to the Internet allows us to admire objects and artworks exhibited worldwide from the comfort of our home, visiting a museum or an exhibition remains an essential experience today. Current technologies can help make that experience even more satisfying. For instance, they can assist the user during the visit, personalizing her experience by suggesting the artworks of her higher interest and providing her with related textual and multimedia content. To this aim, it is necessary to automatically acquire information relating to the active user. In this paper, we show how a deep neural network-based approach can allow us to obtain accurate information for understanding the behavior of the visitor alone or in a group. This information can also be used to identify users similar to the active one to suggest not only personalized itineraries but also possible visiting companions for promoting the museum as a vehicle for social and cultural inclusion.
Communications in Computer and Information Science, 2020
2017 IEEE 17th International Conference on Advanced Learning Technologies (ICALT), 2017
The public availability of datasets of teaching resources is an issue for the design, development... more The public availability of datasets of teaching resources is an issue for the design, development and evaluation of Information Retrieval and Recommender Systems in Technology Enhanced Learning. Recently, the Dataset of Joint Educational Entities (DAJEE) has provided the community with a very exhaustive collection of resources coming from Massive Open Online Courses. This work proposes a representation of the DAJEE dataset according to Linked Data principles, interlinking the large amount of resources in DAJEE with the Web of Data. The transcript of the educational resources in DAJEE have been annotated through a Named Entity Recognition tool in order to create interlinks with the DBpedia entities. The DBpedia knowledge base provides additional information related to categories, that can be exploited to infer new knowledge and support reasoning processes.
Current image/video acquisition and analysis techniques allow for not only the identification and... more Current image/video acquisition and analysis techniques allow for not only the identification and classification of objects in a scene but also more sophisticated processing. For example, there are video cameras today able to capture micro facial expressions, namely, facial expressions that occur in a fraction of a second. Such micro expressions can provide useful information to define a person’s emotional state. In this article, we propose to use these features to collect useful information for designing and implementing increasingly effective interactive technologies. In particular, facial micro expressions could be used to develop interfaces capable of fostering the social and cultural inclusion of users belonging to different realities and categories. The preliminary experimental results obtained by recording the reactions of individuals while observing artworks demonstrate the existence of correlations between the action units (i.e., single components of the muscular movement i...
This paper presents a newborn collaboration between heterogeneous AI competences. In particular, ... more This paper presents a newborn collaboration between heterogeneous AI competences. In particular, it describes current work on the integration of machine learning techniques for the automatic generation of contents for an Intelligent Tutoring System grounded on automated planning techniques. The joint use of these two approaches allows on the one hand to facilitate the task of instructional designers in defining and preparing courses, and on the other hand to dynamically support the use of content according to different users context.
The DAtaset of Joint Educational Entities (DAJEE) is a repository which hosts more than 20,000 ed... more The DAtaset of Joint Educational Entities (DAJEE) is a repository which hosts more than 20,000 educational resources crawled from the MOOC platform Coursera. The resources are divided per category according to the MOOC categorization on Coursera, which is, however, very shallow. This contribution focuses on a more meaningful categorization of the resources in DAJEE, tailored to their content. To achieve such goal, our approach enriches the resources in DAJEE with semantic entities by applying state-of-the-art semantic techniques. The result is a significant improvement of the categorization of the resources in DAJEE than the previous version.
Lecture Notes in Computer Science, 2019
The retrieval and composition of educational material are topics that attract many studies from t... more The retrieval and composition of educational material are topics that attract many studies from the field of Information Retrieval and Artificial Intelligence. The Web is gradually gaining popularity among teachers and students as a source of learning resources. This transition is, however, facing skepticism from some scholars in the field of education. The main concern is about the quality and reliability of the teaching on the Web. While online educational repositories are explicitly built for educational purposes by competent teachers, web pages are designed and created for offering different services, not only education. In this study, we analyse if the Internet is a good source of teaching material compared to the currently available repositories in education. Using a collection of 50 queries related to educational topics, we compare how many useful learning resources a teacher can retrieve in Google and three popular learning object repositories. The results are very insightful and in favour of Google supported by the t-tests. For most of the queries, Google retrieves a larger number of useful web pages than the repositories (\(p < .01\)), and no queries resulted in zero useful items. Instead, the repositories struggle to find even one relevant material for many queries. This study is clear evidence that even though the repositories offer a richer description of the learning resources through metadata, it is time to undertake more research towards the retrieval of web pages for educational applications.
2021 25th International Conference Information Visualisation (IV), 2021
Concept maps are significant tools able to support several tasks in the educational area such as ... more Concept maps are significant tools able to support several tasks in the educational area such as curriculum design, knowledge organization and modeling, students’ assessment and many others. They are also successfully used in learning activities in which students have to represent domain knowledge according to teacher’s assignment. In this context, the development of Learning Analytics approaches would benefit of methods that automatically compare concept maps. Detecting concept maps similarities is relevant to identify how the same concepts are used in different knowledge representations. Algorithms for comparing graphs have been extensively studied in the literature, but they do not appear appropriate for concept maps. In concept maps, concepts exposed are at least as relevant as the structure that contains them. Neglecting the semantic and didactic aspect inevitably causes inaccuracies and the consequently limited applicability in Learning Analytics approaches. In this work, starting from an algorithm which compares didactic characteristic of concept maps, we present an extension which exploits a semantic approach to catch the actual meaning of the concepts expressed in the nodes of the map.
Intelligent Tutoring Systems, 2021
This paper shows how explicit parallel function calls can be defined and implemented on top of Co... more This paper shows how explicit parallel function calls can be defined and implemented on top of Concurrent ML hidingthedetails aboutcreation and communication of differentthreads. Theprovided parallel schemes are mainly inspired bytheAnd/Or-parallelism known from logic programmingand pipelining whichtogether provideanoutlinehowother schemes can be coded. Theapplication of these functions is demonstrated by examples taken from logic andalgebraic computation. 2 1
Lecture Notes in Computer Science, 2002
The "planning as satisfiability" paradigm, which reduces solving a planning problem P to the sear... more The "planning as satisfiability" paradigm, which reduces solving a planning problem P to the search of a model of a logical description of P , relies on the assumption that the agent has complete knowledge and control over the world. This work faces the problem of planning in the presence of incomplete information and/or exogenous events, still keeping inside the "planning as satisfiability" paradigm, in the context of linear time logic. We give a logical characterization of a "conditioned model", which represents a plan solving a given problem together with a set of "conditions" that guarantee its executability. During execution, conditions have to be checked by means of sensing actions. When a condition turns out to be false, a different "conditioned plan" must be considered. A whole conditional plan is represented by a set of conditioned models. The interest of splitting a conditional plan into significant sub-parts is due to the heavy computational complexity of conditional planning. The paper presents an extension of the standard tableau calculus for linear time logic, allowing one to extract from a single open branch a conditioned model of the initial set of formulae, i.e. a partial description of a model and a set of conditions U guaranteeing its "executability". As can be expected, if U is required to be minimal, the analysis of a single branch is not sufficient. We show how a global view on the whole tableau can be used to prune U from redundant conditions. In any case, if the calculus is to be used with the aim of producing the whole conditional plan off-line, a complete tableau must be built. On the other hand, a single conditioned model can be used when planning and execution (with sensing actions) are intermingled. In that case, the requirement for minimality can reasonably be relaxed.
The planning as satis ability" paradigm, which reduces solving a planning problem P to the s... more The planning as satis ability" paradigm, which reduces solving a planning problem P to the search of a model of a logical description of P , relies on the assumption that the agent has complete knowledge and control over the world. This work faces the problem of planning in the presence of incomplete information and/or exogenous events, still keeping inside the planning as satis ability" paradigm, in the context of linear time logic.
Texts and Monographs in Symbolic Computation, 1997
ABSTRACT The aim of the paper is to show the effectiveness of the p-adic arithmetic in scientific... more ABSTRACT The aim of the paper is to show the effectiveness of the p-adic arithmetic in scientific computation by selecting and solving problems which manipulates “big” numbers. By “big” integer number, we mean a number which is greater than the maximum integer that can be stored in a word of a given computer. We define a rational number (in reduced form) a/b to be big when a or b (or both) is a big integer. The reason of our interest in big numbers manipulations is in that they often arise as intermediate or final results in various algebraic algorithms such as Gröbner bases, cylindrical algebraic decomposition (Collins 1975), characteristic sets, polynomial remainder sequences, exponentiation and Gaussian elimination.
Texts and Monographs in Symbolic Computation, 1997
In this paper we propose the use of the p-adic arithmetic as a basic computational tool for a sym... more In this paper we propose the use of the p-adic arithmetic as a basic computational tool for a symbolic computation system in the framework of the TASSO project. This arithmetic has been chosen for two main reasons.
Lecture Notes in Computer Science, 1989
In the past years, great attention has been payed to approximated p-adic arithmetic expressed in ... more In the past years, great attention has been payed to approximated p-adic arithmetic expressed in the form of Hensel codes and several contributions have made this p-adic arithmetic really effective, just according to this new consideration of it. However it has been shown that the appliability of p-adic arithmetic is strongly constrained by the size of rational numbers which constitutes
Lecture Notes in Computer Science, 1993
... digits, as stated in the following definition. Definitionl (Hensel Codes). Given a prime numb... more ... digits, as stated in the following definition. Definitionl (Hensel Codes). Given a prime number p, a Hensel code of length r of any rational nmnber ~ = (c/d). pe is a pair (manta,exp,) = (. aoal ".a,.-1,e), where the r leftmost digits and ...
Lecture Notes in Computer Science, 2003
Page 1. Planning under Uncertainty in Linear Time Logic * Marta Cialdea Mayer, Carla Limongelli, ... more Page 1. Planning under Uncertainty in Linear Time Logic * Marta Cialdea Mayer, Carla Limongelli, Andrea Orlandini, and Valentina Poggioni ... AAAI Press / The MIT Press, 1996. 325 [3] P. Bertoli, A. Cimatti, M. Roveri, and P. Traverso. ...
Lecture Notes in Computer Science, 2005
This paper presents the planning system Pdk (Planning with Domain Knowledge), based on the transl... more This paper presents the planning system Pdk (Planning with Domain Knowledge), based on the translation of planning problems into Linear Time Logic theories, in such a way that finding solution plans is reduced to model search. The model search mechanism is based on temporal tableaux. The planning language accepted by the system allows one to specify extra problem dependent information, that can be of help both in reducing the search space and finding plans of better quality.
IEEE Access
The Web offers an unprecedented number of resources and has become the most popular source of inf... more The Web offers an unprecedented number of resources and has become the most popular source of information for students shaping their understanding of a new topic, and for instructors selecting relevant material for learning and teaching activities. Even though search engines are the most widely used tools for searching for educational content, the realities of the learning and teaching processes make the retrieval and evaluation of educational resources more complex than they are for other goods or services. The lack of recourse to educational metadata in web pages, as well as the size of the Web itself, call for specific techniques to be adopted for a more effective ranking of educational content. In this study, we propose an innovative approach based on semantic technologies. The SemanticSearch approach described in this paper leverages knowledge graph representation of teaching contexts and proposes a new ranking method for rating educational web content. In the literature we find an Educational Ranking Principle that ranks web pages for a specific teaching context. In this study, we integrate the Educational Ranking Principle with semantic data to extend the experimentation and analyse performance further. We undertake an evaluation involving university teachers, considering more than 70 queries to measure the SemanticSearch performance against the Educational Ranking Principle in addition to two state-of-the-art methodologies: Tf-Idf and BM25F. Paired t-tests of four accuracy measures provide statistical evidence for improvements made by using SemanticSearch method when compared to the three baselines. INDEX TERMS Semantic-based retrieval, instructional materials, web ranking principles, teacher support.
Although ubiquitous and fast access to the Internet allows us to admire objects and artworks exhi... more Although ubiquitous and fast access to the Internet allows us to admire objects and artworks exhibited worldwide from the comfort of our home, visiting a museum or an exhibition remains an essential experience today. Current technologies can help make that experience even more satisfying. For instance, they can assist the user during the visit, personalizing her experience by suggesting the artworks of her higher interest and providing her with related textual and multimedia content. To this aim, it is necessary to automatically acquire information relating to the active user. In this paper, we show how a deep neural network-based approach can allow us to obtain accurate information for understanding the behavior of the visitor alone or in a group. This information can also be used to identify users similar to the active one to suggest not only personalized itineraries but also possible visiting companions for promoting the museum as a vehicle for social and cultural inclusion.
Communications in Computer and Information Science, 2020
2017 IEEE 17th International Conference on Advanced Learning Technologies (ICALT), 2017
The public availability of datasets of teaching resources is an issue for the design, development... more The public availability of datasets of teaching resources is an issue for the design, development and evaluation of Information Retrieval and Recommender Systems in Technology Enhanced Learning. Recently, the Dataset of Joint Educational Entities (DAJEE) has provided the community with a very exhaustive collection of resources coming from Massive Open Online Courses. This work proposes a representation of the DAJEE dataset according to Linked Data principles, interlinking the large amount of resources in DAJEE with the Web of Data. The transcript of the educational resources in DAJEE have been annotated through a Named Entity Recognition tool in order to create interlinks with the DBpedia entities. The DBpedia knowledge base provides additional information related to categories, that can be exploited to infer new knowledge and support reasoning processes.
Current image/video acquisition and analysis techniques allow for not only the identification and... more Current image/video acquisition and analysis techniques allow for not only the identification and classification of objects in a scene but also more sophisticated processing. For example, there are video cameras today able to capture micro facial expressions, namely, facial expressions that occur in a fraction of a second. Such micro expressions can provide useful information to define a person’s emotional state. In this article, we propose to use these features to collect useful information for designing and implementing increasingly effective interactive technologies. In particular, facial micro expressions could be used to develop interfaces capable of fostering the social and cultural inclusion of users belonging to different realities and categories. The preliminary experimental results obtained by recording the reactions of individuals while observing artworks demonstrate the existence of correlations between the action units (i.e., single components of the muscular movement i...
This paper presents a newborn collaboration between heterogeneous AI competences. In particular, ... more This paper presents a newborn collaboration between heterogeneous AI competences. In particular, it describes current work on the integration of machine learning techniques for the automatic generation of contents for an Intelligent Tutoring System grounded on automated planning techniques. The joint use of these two approaches allows on the one hand to facilitate the task of instructional designers in defining and preparing courses, and on the other hand to dynamically support the use of content according to different users context.
The DAtaset of Joint Educational Entities (DAJEE) is a repository which hosts more than 20,000 ed... more The DAtaset of Joint Educational Entities (DAJEE) is a repository which hosts more than 20,000 educational resources crawled from the MOOC platform Coursera. The resources are divided per category according to the MOOC categorization on Coursera, which is, however, very shallow. This contribution focuses on a more meaningful categorization of the resources in DAJEE, tailored to their content. To achieve such goal, our approach enriches the resources in DAJEE with semantic entities by applying state-of-the-art semantic techniques. The result is a significant improvement of the categorization of the resources in DAJEE than the previous version.
Lecture Notes in Computer Science, 2019
The retrieval and composition of educational material are topics that attract many studies from t... more The retrieval and composition of educational material are topics that attract many studies from the field of Information Retrieval and Artificial Intelligence. The Web is gradually gaining popularity among teachers and students as a source of learning resources. This transition is, however, facing skepticism from some scholars in the field of education. The main concern is about the quality and reliability of the teaching on the Web. While online educational repositories are explicitly built for educational purposes by competent teachers, web pages are designed and created for offering different services, not only education. In this study, we analyse if the Internet is a good source of teaching material compared to the currently available repositories in education. Using a collection of 50 queries related to educational topics, we compare how many useful learning resources a teacher can retrieve in Google and three popular learning object repositories. The results are very insightful and in favour of Google supported by the t-tests. For most of the queries, Google retrieves a larger number of useful web pages than the repositories (\(p < .01\)), and no queries resulted in zero useful items. Instead, the repositories struggle to find even one relevant material for many queries. This study is clear evidence that even though the repositories offer a richer description of the learning resources through metadata, it is time to undertake more research towards the retrieval of web pages for educational applications.
2021 25th International Conference Information Visualisation (IV), 2021
Concept maps are significant tools able to support several tasks in the educational area such as ... more Concept maps are significant tools able to support several tasks in the educational area such as curriculum design, knowledge organization and modeling, students’ assessment and many others. They are also successfully used in learning activities in which students have to represent domain knowledge according to teacher’s assignment. In this context, the development of Learning Analytics approaches would benefit of methods that automatically compare concept maps. Detecting concept maps similarities is relevant to identify how the same concepts are used in different knowledge representations. Algorithms for comparing graphs have been extensively studied in the literature, but they do not appear appropriate for concept maps. In concept maps, concepts exposed are at least as relevant as the structure that contains them. Neglecting the semantic and didactic aspect inevitably causes inaccuracies and the consequently limited applicability in Learning Analytics approaches. In this work, starting from an algorithm which compares didactic characteristic of concept maps, we present an extension which exploits a semantic approach to catch the actual meaning of the concepts expressed in the nodes of the map.
Intelligent Tutoring Systems, 2021
This paper shows how explicit parallel function calls can be defined and implemented on top of Co... more This paper shows how explicit parallel function calls can be defined and implemented on top of Concurrent ML hidingthedetails aboutcreation and communication of differentthreads. Theprovided parallel schemes are mainly inspired bytheAnd/Or-parallelism known from logic programmingand pipelining whichtogether provideanoutlinehowother schemes can be coded. Theapplication of these functions is demonstrated by examples taken from logic andalgebraic computation. 2 1
Lecture Notes in Computer Science, 2002
The "planning as satisfiability" paradigm, which reduces solving a planning problem P to the sear... more The "planning as satisfiability" paradigm, which reduces solving a planning problem P to the search of a model of a logical description of P , relies on the assumption that the agent has complete knowledge and control over the world. This work faces the problem of planning in the presence of incomplete information and/or exogenous events, still keeping inside the "planning as satisfiability" paradigm, in the context of linear time logic. We give a logical characterization of a "conditioned model", which represents a plan solving a given problem together with a set of "conditions" that guarantee its executability. During execution, conditions have to be checked by means of sensing actions. When a condition turns out to be false, a different "conditioned plan" must be considered. A whole conditional plan is represented by a set of conditioned models. The interest of splitting a conditional plan into significant sub-parts is due to the heavy computational complexity of conditional planning. The paper presents an extension of the standard tableau calculus for linear time logic, allowing one to extract from a single open branch a conditioned model of the initial set of formulae, i.e. a partial description of a model and a set of conditions U guaranteeing its "executability". As can be expected, if U is required to be minimal, the analysis of a single branch is not sufficient. We show how a global view on the whole tableau can be used to prune U from redundant conditions. In any case, if the calculus is to be used with the aim of producing the whole conditional plan off-line, a complete tableau must be built. On the other hand, a single conditioned model can be used when planning and execution (with sensing actions) are intermingled. In that case, the requirement for minimality can reasonably be relaxed.
The planning as satis ability" paradigm, which reduces solving a planning problem P to the s... more The planning as satis ability" paradigm, which reduces solving a planning problem P to the search of a model of a logical description of P , relies on the assumption that the agent has complete knowledge and control over the world. This work faces the problem of planning in the presence of incomplete information and/or exogenous events, still keeping inside the planning as satis ability" paradigm, in the context of linear time logic.
Texts and Monographs in Symbolic Computation, 1997
ABSTRACT The aim of the paper is to show the effectiveness of the p-adic arithmetic in scientific... more ABSTRACT The aim of the paper is to show the effectiveness of the p-adic arithmetic in scientific computation by selecting and solving problems which manipulates “big” numbers. By “big” integer number, we mean a number which is greater than the maximum integer that can be stored in a word of a given computer. We define a rational number (in reduced form) a/b to be big when a or b (or both) is a big integer. The reason of our interest in big numbers manipulations is in that they often arise as intermediate or final results in various algebraic algorithms such as Gröbner bases, cylindrical algebraic decomposition (Collins 1975), characteristic sets, polynomial remainder sequences, exponentiation and Gaussian elimination.
Texts and Monographs in Symbolic Computation, 1997
In this paper we propose the use of the p-adic arithmetic as a basic computational tool for a sym... more In this paper we propose the use of the p-adic arithmetic as a basic computational tool for a symbolic computation system in the framework of the TASSO project. This arithmetic has been chosen for two main reasons.
Lecture Notes in Computer Science, 1989
In the past years, great attention has been payed to approximated p-adic arithmetic expressed in ... more In the past years, great attention has been payed to approximated p-adic arithmetic expressed in the form of Hensel codes and several contributions have made this p-adic arithmetic really effective, just according to this new consideration of it. However it has been shown that the appliability of p-adic arithmetic is strongly constrained by the size of rational numbers which constitutes
Lecture Notes in Computer Science, 1993
... digits, as stated in the following definition. Definitionl (Hensel Codes). Given a prime numb... more ... digits, as stated in the following definition. Definitionl (Hensel Codes). Given a prime number p, a Hensel code of length r of any rational nmnber ~ = (c/d). pe is a pair (manta,exp,) = (. aoal ".a,.-1,e), where the r leftmost digits and ...
Lecture Notes in Computer Science, 2003
Page 1. Planning under Uncertainty in Linear Time Logic * Marta Cialdea Mayer, Carla Limongelli, ... more Page 1. Planning under Uncertainty in Linear Time Logic * Marta Cialdea Mayer, Carla Limongelli, Andrea Orlandini, and Valentina Poggioni ... AAAI Press / The MIT Press, 1996. 325 [3] P. Bertoli, A. Cimatti, M. Roveri, and P. Traverso. ...
Lecture Notes in Computer Science, 2005
This paper presents the planning system Pdk (Planning with Domain Knowledge), based on the transl... more This paper presents the planning system Pdk (Planning with Domain Knowledge), based on the translation of planning problems into Linear Time Logic theories, in such a way that finding solution plans is reduced to model search. The model search mechanism is based on temporal tableaux. The planning language accepted by the system allows one to specify extra problem dependent information, that can be of help both in reducing the search space and finding plans of better quality.