ThesearetheproceedingsofthefourthbiennialconferenceintheIntelligentData Analysisseries. TheconferencetookplaceinCascais,Portugal,13¿15September 2001. Thethemeofthisconferenceseriesistheuseofcomputersinintelligent waysindataanalysis,includingtheexplorationofintelligentprogramsfordata analysis. Dataanalytictoolscontinuetodevelop,drivenbythecomputerrevo- tion. Methodswhichwouldhaverequiredunimaginableamountsofcomputing power,andwhichwouldhavetakenyearstoreachaconclusion,cannowbe appliedwitheaseandvirtuallyinstantly. Suchmethodsarebeingdevelopedby avarietyofintellectualcommunities,includingstatistics,arti?cialintelligence, neuralnetworks,machinelearning,datamining,andinteractivedynamicdata visualization. Thisconferenceseriesseekstobringtogetherresearchersstudying theuseofintelligentdataanalysisinthesevariousdisciplines,tostimulate- teractionsothateachdisciplinemaylearnfromtheothers. Soastoencourage suchinteraction,wedeliberatelykepttheconferencetoasingletrackmeeting. Thismeantthat,ofthealmost150submissionswereceived,wewereableto selectonly23fororalpresentationand16forposterpresentation. Inaddition tothesecontributedpapers,therewasakeynoteaddressfromDarylPregibon, invitedpresentationsfromKatharinaMorik,RolfBackhofen,andSunilRao,and aspecial¿datachallenge¿session,whereresearchersdescribedtheirattemptsto analyseachallengingdatasetprovidedbyPaulCohen. Thisacceptancerate enabledustoensureahighqualityconference,whilealsopermittingustop- videgoodcoverageofthevarioustopicssubsumedwithinthegeneralheading ofintelligentdataanalysis. Wewouldliketoexpressourthanksandappreciationtoeveryoneinvolved intheorganizationofthemeetingandtheselectionofthepapers. Itisthe behind-the-scenese?ortswhichensurethesmoothrunningandsuccessofany conference. Wewouldalsoliketoexpressourgratitudetothesponsors:Fundac¿ ¿ao paraaCi¿enciaeaTecnologia,Minist¿eriodaCi¿enciaedaTecnologia,Faculdade deCi¿enciaseTecnologia,UniversidadeNovadeLisboa,Fundäc¿aoCalousteG- benkianandIPEInvestimentoseParticipac¿ ¿oe

Includes supplementary material: sn.pub/extras

The Fourth International Symposium on Intelligent Data Analysis.- Feature Characterization in Scientific Datasets.- Relevance Feedback in the Bayesian Network Retrieval Model: An Approach Based on Term Instantiation.- Generating Fuzzy Summaries From Fuzzy Multidimensional Databases.- A Mixture-of-Experts Framework for Learning from Imbalanced Data Sets.- Predicting Time-Varying Functions with Local Models.- Building Models of Ecological Dynamics Using HMM Based Temporal Data Clustering - A Preliminary Study.- Tagging with Small Training Corpora.- A Search Engine for Morphologically Complex Languages.- Errors Detection and Correction in Large Scale Data Collecting.- A New Framework to Assess Association Rules.- Communities of Interest.- An Evaluation of Grading Classifiers.- Finding Informative Rules in Interval Sequences.- Correlation-Based and Contextual Merit-Based Ensemble Feature Selection.- Nonmetric Multidimensional Scaling with Neural Networks.- Functional Trees for Regression.- Data Mining with Products of Trees.- S 3Bagging: Fast Classifier Induction Method with Subsampling and Bagging.- RNA-Sequence-Structure Properties and Selenocysteine Insertion.- An Algorithm for Segmenting Categorical Time Series into Meaningful Episodes.- An Empirical Comparison of Pruning Methods for Ensemble Classifiers.- A framework for Modelling Short, High-Dimensional Multivariate Time Series: Preliminary Results in Virus Gene Expression Data Analysis.- Using Multiattribute Prediction Suffix Graphs for Spanish Part-of-Speech Tagging.- Self-Supervised Chinese Word Segmentation.- Analyzing Data Clusters: A Rough Sets Approach to Extract Cluster-Defining Symbolic Rules.- Finding Polynomials to Fit Multivariate Data Having Numeric and Nominal Variables.- Fluent Learning: Elucidatingthe Structure of Episodes.- An Intelligent Decision Support Model for Aviation Weather Forcasting.- MAMBO: Discovering Association Rules Based on Conditional Independencies.- Model Building for Random Fields.- Active Hidden Markov Models for Information Extraction.- Adaptive Lightweight Text Filtering.- General Algorithm for Approximate Inference in Multiply Sectioned Bayesian Networks.- Investigating Temporal Patterns of Fault Behaviour Within Large Telephony Networks.- Closed Set Based Discovery of Representative Association Rules.- Intelligent Sensor Analysis and Actuator Control.- Sampling of Highly Correlated Data for Polynomial Regression and Model Discovery.- The IDA'01 Robot Data Challenge.- The IDA'01 Robot Data Challenge.