Ricardo Conejo | Universidad de Málaga (original) (raw)

Papers by Ricardo Conejo

Research paper thumbnail of Fuzzy-Lisp: Un Modelo De Calculo Funcional Borroso

Se define teóricamente una extensión del modelo de evaluación Lisp básico, de forma que, mediante... more Se define teóricamente una extensión del modelo de evaluación Lisp básico, de forma que, mediante el empleo sistemático del principio de extensionalidad, se puedan evaluar tanto expresiones difusas como expresiones de argumentos difusos. Se presenta una sencilla implementación de este modelo, realizada en Common Lisp.

Research paper thumbnail of BABEL (versión para Windows): Batería para aprendizajes básicos de estimulación lectora

Creacion De Materiales Para La Innovacion Educativa Con Nuevas Tecnologias Vol 1 1998 Isbn 84 600 9457 X Pags 227 229, 1998

Research paper thumbnail of Data Calibration for Statistical-Based Assessment in Constraint-Based Tutors

Knowledge-Based Systems, 2016

Research paper thumbnail of Personal attributes of authors and reviewers, social bias and the outcomes of peer review: a case study

F1000Research, 2015

Peer review is the &a... more Peer review is the "gold standard" for evaluating journal and conference papers, research proposals, on-going projects and university departments. However, it is widely believed that current systems are expensive, conservative and prone to various forms of bias. One form of bias identified in the literature is "social bias" linked to the personal attributes of authors and reviewers. To quantify the importance of this form of bias in modern peer review, we analyze three datasets providing information on the attributes of authors and reviewers and review outcomes: one from Frontiers - an open access publishing house with a novel interactive review process, and two from Spanish and international computer science conferences, which use traditional peer review. We use a random intercept model in which review outcome is the dependent variable, author and reviewer attributes are the independent variables and bias is defined by the interaction between author and reviewer attributes. We find no evidence of bias in terms of gender, or the language or prestige of author and reviewer institutions in any of the three datasets, but some weak evidence of regional bias in all three. Reviewer gender and the language and prestige of reviewer institutions appear to have little effect on review outcomes, but author gender, and the characteristics of author institutions have moderate to large effects. The methodology used cannot determine whether these are due to objective differences in scientific merit or entrenched biases shared by all reviewers.

Research paper thumbnail of The structure and complexity of Nash equilibria for a selfish routing game

Theoretical Computer Science, 2009

In this work, we study the combinatorial structure and the computational complexity of Nash equil... more In this work, we study the combinatorial structure and the computational complexity of Nash equilibria for a certain game that models selfish routing over a network consisting of m parallel links. We assume a collection of n users, each employing a mixed strategy, which is a probability distribution over links, to control the routing of its own assigned traffic. In a Nash equilibrium, each user selfishly routes its traffic on those links that minimize its expected latency cost, given the network congestion caused by the other users. The social cost of a Nash equilibrium is the expectation, over all random choices of the users, of the maximum, over all links, latency through a link. We embark on a systematic study of several algorithmic problems related to the computation of Nash equilibria for the selfish routing game we consider. In a nutshell, these problems relate to deciding the existence of a Nash equilibrium, constructing a Nash equilibrium with given support characteristics, constructing the worst Nash equilibrium (the one with maximum social cost), constructing the best Nash equilibrium (the one with minimum social cost), or computing the social cost of a (given) Nash equilibrium. Our work provides a comprehensive collection of efficient algorithms, hardness results (both as N P-hardness and #P-completeness results), and structural results for these algorithmic problems. Our results span and contrast a wide range of assumptions on the syntax of the Nash equilibria and on the parameters of the system.

Research paper thumbnail of User Modeling, Adaption and Personalization

Lecture Notes in Computer Science, 2011

Research paper thumbnail of Exploring Quality of Constraints for Assessment in Problem Solving Environments

Lecture Notes in Computer Science, 2012

One of the approaches that has demonstrated by far its efficiency as a tutorial strategy in probl... more One of the approaches that has demonstrated by far its efficiency as a tutorial strategy in problem solving learning environments is the Constraint-Based Modeling (CBM). In existing works it has been combined with a datadriven technique for automatic assessment, the Item Response Theory (IRT). The result is a well-founded model for assessing students while solving problems. In this paper a novel technique for studying quality of constraints for this type of assessment is presented. It has been tested with two new systems, an independent component for assessment that implements CBM with IRT, which provides assessment to a new problem solving environment developed to assess the students' skills in decision-making in project investments. The results of testing our approach and the application of these two systems with undergraduate students are also discussed in this paper.

Research paper thumbnail of Automata, languages and programming-Preface

Research paper thumbnail of Validating Item Response Theory Models in Simulated Environments

Research paper thumbnail of Context-aware Assessment Using QR-codes

ABSTRACT In this paper we present the implementation of a general mechanism to deliver tests base... more ABSTRACT In this paper we present the implementation of a general mechanism to deliver tests based on mobile devices and matrix codes. The system is an extension of Siette, and has not been specifically developed for any subject matter. To evaluate the performance of the system and show some of its capabilities, we have developed a test for a second-year college course on Botany at the School of Forestry Engineering. Students were equipped with iPads and took an outdoor test on plant species identification. All students were able to take and complete the test in a reasonable time. Opinions expressed anonymously by the students in a survey about the usability of the system and the usefulness of the test were very favorable. We think that the application presented in this paper can broaden the applicability of automatic assessment techniques

Research paper thumbnail of An Intelligent Assistant for the Design of Green Areas

Knowledge Based Systems for Civil & Structural Engineering, 1993

Research paper thumbnail of Personalized Adaptation to Device Characteristics

Lecture Notes in Computer Science, 2002

Device characteristics, such as screen size and means of interaction, and the context in which a ... more Device characteristics, such as screen size and means of interaction, and the context in which a device is used, seriously affect the user's mental representation of an information environment and its intended use. We hypothesize that user characteristics are valuable resources for determining which information is of interest in specific situations. Our project goal is to design mechanisms for adapting navigation support to device characteristics and its context of use, thereby considering that user goals and the resulting expected navigation behavior might be subject to change.

Research paper thumbnail of Bias in peer review: a case study

F1000Research, 2015

Peer review is the "gold standard" for evaluating journal and conference papers, research proposa... more Peer review is the "gold standard" for evaluating journal and conference papers, research proposals, on-going projects and university departments. However, it is widely believed that current systems are expensive, conservative and prone to various forms of bias. One form of bias identified in the literature is "social bias" linked to the personal attributes of authors and reviewers. To quantify the importance of this form of bias in modern peer review, we analyze three datasets providing information on the attributes of authors and reviewers and review outcomes: one from Frontiers -an open access publishing house with a novel interactive review process, and two from Spanish and international computer science conferences, which use traditional peer review. We use a random intercept model in which review outcome is the dependent variable, author and reviewer attributes are the independent variables and bias is defined by the interaction between author and reviewer attributes. We find no evidence of bias in terms of gender, or the language or prestige of author and reviewer institutions in any of the three datasets, but some weak evidence of regional bias in all three. Reviewer gender and the language and prestige of reviewer institutions appear to have little effect on review outcomes, but author gender, and the characteristics of author institutions have large effects. The methodology used cannot determine whether these are due to objective differences in scientific merit or entrenched biases shared by all reviewers.

Research paper thumbnail of Measuring Procedural Knowledge in Problem Solving Environments with Item Response Theory

Lecture Notes in Computer Science, 2013

Research paper thumbnail of Statistical Techniques to Explore the Quality of Constraints in Constraint-Based Modeling Environments

International Journal of Artificial Intelligence in Education, 2013

ABSTRACT One of the most popular student modeling approaches is Constraint-Based Modeling (CBM). ... more ABSTRACT One of the most popular student modeling approaches is Constraint-Based Modeling (CBM). It is an efficient approach that can be easily applied inside an Intelligent Tutoring System (ITS). Even with these characteristics, building new ITSs requires carefully designing the domain model to be taught because different sources of errors could affect the efficiency of the system. In this paper a novel mechanism for studying the quality of the elements in the domain model of CBM systems is presented. This mechanism combines CBM with the Item Response Theory (IRT), a data-driven technique for automatic assessment. The goal is to improve the quality of the elements that are used in problem solving environments for assessment or instruction. In this paper we propose a set of statistical techniques, i.e., the analysis of the point-biserial correlation, the Cronbach’s alpha and the information function, to explore the quality of constraints. Two different tools have been used to test this approach: a problem solving environment designed to assess students in project investment analysis; and an independent component that performs assessments using CBM and IRT. Results suggest that the three methods produce consistent diagnosis and may be complementary in some cases. In the experiments we have carried out they were able to detect faulty, bad and good quality constraints.

Research paper thumbnail of An empirical study on the quantitative notion of task difficulty

Expert Systems with Applications, 2014

ABSTRACT Most Adaptive and Intelligent Web-based Educational Systems (AIWBES) use tasks in order ... more ABSTRACT Most Adaptive and Intelligent Web-based Educational Systems (AIWBES) use tasks in order to collect evidence for inferring knowledge states and adapt the learning process appropriately. To this end, it is important to determine the difficulty of tasks posed to the student. In most situations, difficulty values are directly provided by one or more persons. In this paper we explore the relationship between task difficulty estimations made by two different types of individuals, teachers and students, and compare these values with those estimated from experimental data. We have performed three different experiments with three different real student samples. All these experiments have been done using the SIETTE web-based assessment system. We conclude that heuristic estimation is not always the best solution and claim that automatic estimation should improve the performance of AIWBES.

Research paper thumbnail of Current topics in artificial intelligence(San Sebastian, 12-14 November 2003, revised selected papers)

Lecture notes in computer science

RefDoc Refdoc est un service / is powered by. ...

Research paper thumbnail of La Segunda Conferencia Internacional sobre Sistemas Hipermedia y Web Adaptativos (AH2002)

Research paper thumbnail of LEDA: A Language for Heuristic Architectural Design

Research paper thumbnail of Acerca de la Calculabilidad de las Funciones Difusas

Research paper thumbnail of Fuzzy-Lisp: Un Modelo De Calculo Funcional Borroso

Se define teóricamente una extensión del modelo de evaluación Lisp básico, de forma que, mediante... more Se define teóricamente una extensión del modelo de evaluación Lisp básico, de forma que, mediante el empleo sistemático del principio de extensionalidad, se puedan evaluar tanto expresiones difusas como expresiones de argumentos difusos. Se presenta una sencilla implementación de este modelo, realizada en Common Lisp.

Research paper thumbnail of BABEL (versión para Windows): Batería para aprendizajes básicos de estimulación lectora

Creacion De Materiales Para La Innovacion Educativa Con Nuevas Tecnologias Vol 1 1998 Isbn 84 600 9457 X Pags 227 229, 1998

Research paper thumbnail of Data Calibration for Statistical-Based Assessment in Constraint-Based Tutors

Knowledge-Based Systems, 2016

Research paper thumbnail of Personal attributes of authors and reviewers, social bias and the outcomes of peer review: a case study

F1000Research, 2015

Peer review is the &a... more Peer review is the "gold standard" for evaluating journal and conference papers, research proposals, on-going projects and university departments. However, it is widely believed that current systems are expensive, conservative and prone to various forms of bias. One form of bias identified in the literature is "social bias" linked to the personal attributes of authors and reviewers. To quantify the importance of this form of bias in modern peer review, we analyze three datasets providing information on the attributes of authors and reviewers and review outcomes: one from Frontiers - an open access publishing house with a novel interactive review process, and two from Spanish and international computer science conferences, which use traditional peer review. We use a random intercept model in which review outcome is the dependent variable, author and reviewer attributes are the independent variables and bias is defined by the interaction between author and reviewer attributes. We find no evidence of bias in terms of gender, or the language or prestige of author and reviewer institutions in any of the three datasets, but some weak evidence of regional bias in all three. Reviewer gender and the language and prestige of reviewer institutions appear to have little effect on review outcomes, but author gender, and the characteristics of author institutions have moderate to large effects. The methodology used cannot determine whether these are due to objective differences in scientific merit or entrenched biases shared by all reviewers.

Research paper thumbnail of The structure and complexity of Nash equilibria for a selfish routing game

Theoretical Computer Science, 2009

In this work, we study the combinatorial structure and the computational complexity of Nash equil... more In this work, we study the combinatorial structure and the computational complexity of Nash equilibria for a certain game that models selfish routing over a network consisting of m parallel links. We assume a collection of n users, each employing a mixed strategy, which is a probability distribution over links, to control the routing of its own assigned traffic. In a Nash equilibrium, each user selfishly routes its traffic on those links that minimize its expected latency cost, given the network congestion caused by the other users. The social cost of a Nash equilibrium is the expectation, over all random choices of the users, of the maximum, over all links, latency through a link. We embark on a systematic study of several algorithmic problems related to the computation of Nash equilibria for the selfish routing game we consider. In a nutshell, these problems relate to deciding the existence of a Nash equilibrium, constructing a Nash equilibrium with given support characteristics, constructing the worst Nash equilibrium (the one with maximum social cost), constructing the best Nash equilibrium (the one with minimum social cost), or computing the social cost of a (given) Nash equilibrium. Our work provides a comprehensive collection of efficient algorithms, hardness results (both as N P-hardness and #P-completeness results), and structural results for these algorithmic problems. Our results span and contrast a wide range of assumptions on the syntax of the Nash equilibria and on the parameters of the system.

Research paper thumbnail of User Modeling, Adaption and Personalization

Lecture Notes in Computer Science, 2011

Research paper thumbnail of Exploring Quality of Constraints for Assessment in Problem Solving Environments

Lecture Notes in Computer Science, 2012

One of the approaches that has demonstrated by far its efficiency as a tutorial strategy in probl... more One of the approaches that has demonstrated by far its efficiency as a tutorial strategy in problem solving learning environments is the Constraint-Based Modeling (CBM). In existing works it has been combined with a datadriven technique for automatic assessment, the Item Response Theory (IRT). The result is a well-founded model for assessing students while solving problems. In this paper a novel technique for studying quality of constraints for this type of assessment is presented. It has been tested with two new systems, an independent component for assessment that implements CBM with IRT, which provides assessment to a new problem solving environment developed to assess the students' skills in decision-making in project investments. The results of testing our approach and the application of these two systems with undergraduate students are also discussed in this paper.

Research paper thumbnail of Automata, languages and programming-Preface

Research paper thumbnail of Validating Item Response Theory Models in Simulated Environments

Research paper thumbnail of Context-aware Assessment Using QR-codes

ABSTRACT In this paper we present the implementation of a general mechanism to deliver tests base... more ABSTRACT In this paper we present the implementation of a general mechanism to deliver tests based on mobile devices and matrix codes. The system is an extension of Siette, and has not been specifically developed for any subject matter. To evaluate the performance of the system and show some of its capabilities, we have developed a test for a second-year college course on Botany at the School of Forestry Engineering. Students were equipped with iPads and took an outdoor test on plant species identification. All students were able to take and complete the test in a reasonable time. Opinions expressed anonymously by the students in a survey about the usability of the system and the usefulness of the test were very favorable. We think that the application presented in this paper can broaden the applicability of automatic assessment techniques

Research paper thumbnail of An Intelligent Assistant for the Design of Green Areas

Knowledge Based Systems for Civil & Structural Engineering, 1993

Research paper thumbnail of Personalized Adaptation to Device Characteristics

Lecture Notes in Computer Science, 2002

Device characteristics, such as screen size and means of interaction, and the context in which a ... more Device characteristics, such as screen size and means of interaction, and the context in which a device is used, seriously affect the user's mental representation of an information environment and its intended use. We hypothesize that user characteristics are valuable resources for determining which information is of interest in specific situations. Our project goal is to design mechanisms for adapting navigation support to device characteristics and its context of use, thereby considering that user goals and the resulting expected navigation behavior might be subject to change.

Research paper thumbnail of Bias in peer review: a case study

F1000Research, 2015

Peer review is the "gold standard" for evaluating journal and conference papers, research proposa... more Peer review is the "gold standard" for evaluating journal and conference papers, research proposals, on-going projects and university departments. However, it is widely believed that current systems are expensive, conservative and prone to various forms of bias. One form of bias identified in the literature is "social bias" linked to the personal attributes of authors and reviewers. To quantify the importance of this form of bias in modern peer review, we analyze three datasets providing information on the attributes of authors and reviewers and review outcomes: one from Frontiers -an open access publishing house with a novel interactive review process, and two from Spanish and international computer science conferences, which use traditional peer review. We use a random intercept model in which review outcome is the dependent variable, author and reviewer attributes are the independent variables and bias is defined by the interaction between author and reviewer attributes. We find no evidence of bias in terms of gender, or the language or prestige of author and reviewer institutions in any of the three datasets, but some weak evidence of regional bias in all three. Reviewer gender and the language and prestige of reviewer institutions appear to have little effect on review outcomes, but author gender, and the characteristics of author institutions have large effects. The methodology used cannot determine whether these are due to objective differences in scientific merit or entrenched biases shared by all reviewers.

Research paper thumbnail of Measuring Procedural Knowledge in Problem Solving Environments with Item Response Theory

Lecture Notes in Computer Science, 2013

Research paper thumbnail of Statistical Techniques to Explore the Quality of Constraints in Constraint-Based Modeling Environments

International Journal of Artificial Intelligence in Education, 2013

ABSTRACT One of the most popular student modeling approaches is Constraint-Based Modeling (CBM). ... more ABSTRACT One of the most popular student modeling approaches is Constraint-Based Modeling (CBM). It is an efficient approach that can be easily applied inside an Intelligent Tutoring System (ITS). Even with these characteristics, building new ITSs requires carefully designing the domain model to be taught because different sources of errors could affect the efficiency of the system. In this paper a novel mechanism for studying the quality of the elements in the domain model of CBM systems is presented. This mechanism combines CBM with the Item Response Theory (IRT), a data-driven technique for automatic assessment. The goal is to improve the quality of the elements that are used in problem solving environments for assessment or instruction. In this paper we propose a set of statistical techniques, i.e., the analysis of the point-biserial correlation, the Cronbach’s alpha and the information function, to explore the quality of constraints. Two different tools have been used to test this approach: a problem solving environment designed to assess students in project investment analysis; and an independent component that performs assessments using CBM and IRT. Results suggest that the three methods produce consistent diagnosis and may be complementary in some cases. In the experiments we have carried out they were able to detect faulty, bad and good quality constraints.

Research paper thumbnail of An empirical study on the quantitative notion of task difficulty

Expert Systems with Applications, 2014

ABSTRACT Most Adaptive and Intelligent Web-based Educational Systems (AIWBES) use tasks in order ... more ABSTRACT Most Adaptive and Intelligent Web-based Educational Systems (AIWBES) use tasks in order to collect evidence for inferring knowledge states and adapt the learning process appropriately. To this end, it is important to determine the difficulty of tasks posed to the student. In most situations, difficulty values are directly provided by one or more persons. In this paper we explore the relationship between task difficulty estimations made by two different types of individuals, teachers and students, and compare these values with those estimated from experimental data. We have performed three different experiments with three different real student samples. All these experiments have been done using the SIETTE web-based assessment system. We conclude that heuristic estimation is not always the best solution and claim that automatic estimation should improve the performance of AIWBES.

Research paper thumbnail of Current topics in artificial intelligence(San Sebastian, 12-14 November 2003, revised selected papers)

Lecture notes in computer science

RefDoc Refdoc est un service / is powered by. ...

Research paper thumbnail of La Segunda Conferencia Internacional sobre Sistemas Hipermedia y Web Adaptativos (AH2002)

Research paper thumbnail of LEDA: A Language for Heuristic Architectural Design

Research paper thumbnail of Acerca de la Calculabilidad de las Funciones Difusas