@conference {Katif2014a,
	title = {Visualization method effectiveness in ontology-based information retrieval tasks involving entity evolution},
	booktitle = {Proceedings of SMAP 2014},
	year = {2014},
	month = {11},
	abstract = {Incorporating digital tools in the business and scientific research workflows is at the moment an on-going process, challenging and demanding as every domain has its own needs in terms of data models and information retrieval methods. The information in some domains involves entity evolution, a characteristic that introduces additional tasks, such as finding all evolution stages of an entity, and poses additional requirements for the information retrieval process. In this paper we present a user study aiming to investigate the effectiveness of current ontology browsing and visualization methods for supporting users in tasks involving research on entity evolution.},
	doi = {10.1109/SMAP.2014.24},
	author = {Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@article {torou2010,
	title = {Historical research in archives: user methodology and supporting tools},
	journal = {International Journal on Digital Libraries},
	volume = {11(1)},
	year = {2010},
	pages = {25{\textendash}36},
	abstract = {Historic research involves finding, using, and correlating informationwithin primary and secondary sources, in order to communicate an understanding of past events. In this process, historians employ their scientific knowledge, experience, and intuition to formulate queries (who was involved in an event, when did an event occur etc.), and subsequently try to locate the pertinent information from their sources. In this article, the authors investigate how historians formulate queries, which query terms are chosen, and how historians proceed in searching for related information in sources. The insight gained from this investigation can be subsequently used for organizing documentswithin historical source repositories and building tools that will enable historians to access the needed informationmore rapidly and fully.},
	doi = {10.1007/s00799-010-0062-4},
	author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@conference {torou2009a,
	title = {Capturing the historical research methodology: an experimental approach},
	booktitle = {Proceedings of International Conference of Education, Research and Innovation (ICERI 2009)},
	year = {2009},
	month = {11},
	abstract = {This paper presents the results of a study on how historians conduct research in a historical archive, and the methodologies they use while searching. Historic research involves finding, using, interpreting and correlating information within primary and secondary sources, in order to understand past events. The collection of historical data is accomplished through methodical and comprehensive research in primary and secondary sources. An important factor in our study was to understand what kind of data and/or information historians are looking for in a library/historical archive, either printed or digitized, and which research methodologies or research models they use while they investigate a historical archive. Since this issue has not been addressed insofar, and therefore there are no methods for elucidating research methodologies or research models that historians employ / use, we formulated a questionnaire comprising of seven information retrieval tasks commonly addressed in the context of historic research. History researchers were asked to describe in detail how they would proceed in searching for the information they need for completing these tasks. Through this procedure we aimed to investigate the different ways a historian can use to tackle a specific question, examine whether there exists a common research methodology, and the historic researchers? expectations and preferences. The insight gained from this investigation can be used for educational purposes, since it could be useful in the creation / development of a methodology for conducting research on historical information. Furthermore, the findings can be exploited in the context of organizing documents within historical source repositories, so as to facilitate the retrieval of documents by historians; finally the presented findings can serve as a preliminary requirement analysis phase for building tools that will enable historians to access more rapidly and fully the information they need.},
	author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@conference {golem2009b,
	title = {Visualizing Hierarchies: Evaluating the Efficiency and Cognitive Effects of Six Visualization Techniques for Browsing and Management Tasks},
	booktitle = {Information Visualization 2009, book of abstracts},
	year = {2009},
	month = {7},
	abstract = {Hierarchical data structures are one of the most commonly used data structures in computer science, and therefore numerous methods and techniques have been proposed for their visualization. In this paper, we present our findings from a user study, in which a number of folder visualization environments were evaluated to assess (a) how efficiently a number of tasks can be performed within the different environments (b) the extent to which using a particular visualization may help the user acquire an accurate cognitive image of the hierarchy structure and its contents and (c) the overall user experience from using a particular visualization environment. The visualization environments considered are representative of major visualization paradigms (zoomable user interfaces, context+focus and space-filling), while both 2D and 3D environments have been included.},
	author = {M. Golemati and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras and C. Halatsis}
}
@inbook {gol2009a,
	title = {Intelligent User Interfaces: Adaptation and Personalization Systems and Technologies},
	year = {2008},
	pages = {188{\textendash}204},
	publisher = {IGI Publishing},
	organization = {IGI Publishing},
	chapter = {Context and Adaptivity-Driven Visualization Method Selection},
	abstract = {Novel and intelligent visualization methods are being developed in order to accommodate user searching and browsing tasks, including new and advanced functionalities. Besides, research in the field of user modeling is progressing in order to personalize these visualization systems, according to its users{\textquoteright} individual profiles. However, employing a single visualization system, may not suit best any information seeking activity. In this paper we present a visualization environment, which is based on a visualization library, i.e. is a set of visualization methods, from which the most appropriate one is selected for presenting information to the user. This selection is performed combining information extracted from the context of the user, the system configuration and the data collection. A set of rules inputs such information and assigns a score to all candidate visualization methods. The presented environment additionally monitors user behavior and preferences to adapt the visualization method selection criteria.},
	author = {M. Golemati and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras and C. Halatsis},
	editor = {C. Mourlas and P. Germanakos}
}
@conference {Golemati2008106,
	title = {An interview-based user study on the use of visualizations for folder browsing},
	booktitle = {Proceedings of the International Conference on Information Visualisation},
	year = {2008},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {106-112},
	abstract = {Hierarchically structured data collections often need to be visualized for the purposes of digital information management and presentation. File browsing, in particular, has an inherent hierarchical structure and plays an important role in the context of Personal Information Management (PIM). A multitude of file browsers are nowadays available, offering different functionalities, while users adopt diverse practices and habits for browsing activities. In this paper, we investigate these aspects to obtain insights into their advantages and disadvantages and suggest solutions in the area of PIM, as well as in other domains employing similar visualization paradigms. The presented study focuses on the two most widespread visualizations used by file browsers, the indented list and zoomable interface paradigms, and assesses their effectiveness for various tasks and contexts, both by exploiting results on existing evaluations on hierarchy visualizations and folder hierarchy visualizations in particular, and by conducting an interviewbased user study. Β{\textcopyright} 2008 IEEE.},
	keywords = {Administrative data processing, File browser visualization, Indented list visualization, Information analysis, Information management, Information science, Intermodulation, Intermodulation measurement, International conferences, Management, Management information systems, Telecommunication services, User study, Windows explorer},
	doi = {10.1109/IV.2008.90},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51749097531\&partnerID=40\&md5=66afc30e74191773d1c950ac83ba9ac7},
	author = {M. Golemati and Akrivi Katifori and E.G. Giannopoulou and I. Daradimos and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@conference {Katifori2008133,
	title = {Selected results of a comparative study of four ontology visualization methods for information retrieval tasks},
	booktitle = {Proceedings of the 2nd International Conference on Research Challenges in Information Science, RCIS 2008},
	year = {2008},
	note = {cited By (since 1996) 0},
	month = {6},
	pages = {133-140},
	abstract = {The need for effective ontology visualization for design, management and browsing has arisen as a result of the progress in the areas of Semantic Web and Personal Information Management. There are several ontology visualizations available through existing ontology management tools, but not as many evaluations to determine their advantages and disadvantages and their suitability for various ontologies and user groups. This work presents selected results of an evaluation of four visualization methods in ProtΓ{\textcopyright}gΓ{\textcopyright}.},
	keywords = {Communication, Comparative studies, Information management, Information retrieval, Information science, Information services, Information theory, Management, Management information systems, Ontology, Ontology managements, Personal Information managements, Semantic Web, Telecommunication services, User groups, User interfaces, Visualization, visualization methods},
	doi = {10.1109/RCIS.2008.4632101},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-57349172797\&partnerID=40\&md5=1f36a9a0febecb929cd7904c84004143},
	author = {Akrivi Katifori and Elena Torou and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@conference {Katifori200832,
	title = {Supporting research in historical archives: Historical information visualization and modeling requirements},
	booktitle = {Proceedings of the International Conference on Information Visualisation},
	year = {2008},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {32-37},
	abstract = {The on-going progress in the area of digital libraries has lead to the beginning of a digitization effort in Historical Archives, as well. The requirements of historical research, which works with histories of entities and incomplete information, create the need for supplementary tools to support users in handling the digitized content. This work is based on a user study of historian information retrieval methods in order to create a set of tools for the context of historical archives, which will facilitate historical data storage, management and visualization. Β{\textcopyright} 2008 IEEE.},
	keywords = {Data visualization, Digital libraries, Heuristics, Historical archive, Information analysis, Information management, Information retrieval, Information science, Information services, Information systems, International conferences, Libraries, Ontology, Search engines, Visualization},
	doi = {10.1109/IV.2008.70},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51749114860\&partnerID=40\&md5=a5b3e7f74314d5651816424c11e6cbc1},
	author = {Akrivi Katifori and Elena Torou and Costas Vassilakis and C. Halatsis}
}
@conference {KatiforiGVLH07,
	title = {Creating an Ontology for the User Profile: Method and Applications},
	booktitle = {RCIS},
	year = {2007},
	month = {4/2007},
	pages = {407{\textendash}412},
	abstract = {User profiling is commonly employed nowadays to enhance usability as well as to support personalization, adaptivity and other user-centric features. Insofar, application designers model user profiles mainly in an ad-hoc manner, hindering thus application interoperability at the user profile level, increasing the amount of work to be done and the possibility of errors or omissions in the profile model. This work aims at creating a user profile ontology that incorporates concepts and properties used to model the user profile. Existing literature, applications and ontologies related to the domain of user context and profiling have been taken into account in order to create a general, comprehensive and extensible user model. This ontology can be used as a reference model, in order to alleviate the aforementioned issues. The model, available for download, is exemplified through its application in two different areas, personal information management and adaptive visualization.},
	author = {Akrivi Katifori and M. Golemati and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@article {Lepouras200779,
	title = {Domain expert user development: The smartgov approach},
	journal = {Communications of the ACM},
	volume = {50},
	number = {9},
	year = {2007},
	month = {sep},
	pages = {79-83},
	publisher = {Association for Computing Machinery (ACM)},
	abstract = {SmartGov project funded by the European Union is a knowledge-based platform that assists pubic-sector employees with suitable expertise to generate online transaction devices by simplifying service development, maintenance, and integration with installed information technology systems. The project delivers intelligent e-forms development and maintenance environment and associated framework for e-government services. SmartGov address various problems faced by the stakeholders while implementing e-services such as limited view of domain experts, lost information, complexity of creating e-forms, and inadequate access. In a SmartGov approach, the implicit knowledge is made explicit in the form of documentation and data validation rules. The central concept of SmartGov is the transaction service element (TSE) that contain metadata and domain knowledge.},
	keywords = {Data validation, Documentation, Information services, Information technology, Knowledge based platform, Knowledge based systems, Metadata, Online systems, Project management, Transaction service element (TSE)},
	doi = {10.1145/1284621.1284623},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34548411694\&partnerID=40\&md5=43df285b5a79ef731b3466106642af9f},
	author = {Giorgos Lepouras and Costas Vassilakis and C. Halatsis and P. Georgiadis}
}
@conference {KatiforiVTLHD07,
	title = {Historical Archive Ontologies Requirements, Modeling and Visualization},
	booktitle = {RCIS},
	year = {2007},
	month = {4},
	pages = {401-406},
	abstract = {Most ontology development methodologies and tools for ontology management deal with ontology snapshots, i.e. they model and manage only the most recent version of ontologies, which is inadequate for contexts where the history of the ontology is of interest, such as historical archives. This work presents a set of requirements for the modeling and visualization of a temporal ontology used as a tool for the representation of historical information. In accordance to these requirements, a visualization plug-in was designed and implemented, featuring a set of tools that enable users to efficiently examine ontology temporal characteristics such as class and instance evolution along the timeline.},
	author = {Akrivi Katifori and Costas Vassilakis and Elena Torou and Giorgos Lepouras and C. Halatsis and I. Daradimos}
}
@article {Vassilakis2007113,
	title = {A knowledge-based approach for developing multi-channel e-government services},
	journal = {Electronic Commerce Research and Applications},
	volume = {6},
	number = {1},
	year = {2007},
	note = {cited By (since 1996) 0},
	pages = {113-124},
	abstract = {Having realised the benefits resulting from delivering on-line public services in the context of electronic government, administrations strive to extend the spectrum of services offered to citizens and enterprises, as well as to engage multiple communication channels in service delivery, in order to increase the target audience and, consequently, the service effectiveness. Insofar, however, only the web channel has been sufficiently used for service delivery, whereas other channels have not been adequately exploited. One of the main reasons of this lag is the cost incurred for the development and maintenance of multiple versions of an electronic service, each version targeted to a different platform. In this paper, we present an approach and the associated tools for developing and maintaining electronic services that allows the automated production of different versions of the electronic service, each targeted to a specific platform. Β{\textcopyright} 2006 Elsevier B.V. All rights reserved.},
	keywords = {Communication channels (information theory), e-government, Electronic commerce, electronic services, EServices, Government data processing, Knowledge based systems, Multi channel service delivery, Online systems, Websites},
	doi = {10.1016/j.elerap.2006.07.004},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33947371200\&partnerID=40\&md5=ebf06c2eee159fbeeab64c607e84415d},
	author = {Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@article {Katifori2007,
	title = {Ontology visualization methods - A survey},
	journal = {ACM Computing Surveys},
	volume = {39},
	number = {4},
	year = {2007},
	note = {cited By (since 1996) 21},
	pages = {10:1-10:43},
	abstract = {Ontologies, as sets of concepts and their interrelations in a specific domain, have proven to be a useful tool in the areas of digital libraries, the semantic web, and personalized information management. As a result, there is a growing need for effective ontology visualization for design, management and browsing. There exist several ontology visualization methods and also a number of techniques used in other contexts that could be adapted for ontology representation. The purpose of this article is to present these techniques and categorize their characteristics and features in order to assist method selection and promote future research in the area of ontology visualization. Β{\textcopyright} 2007 ACM.},
	keywords = {Digital libraries, Human computer interaction, Information management, Ontology, Ontology representation, Ontology visualization, Personalized information management, Semantic Web, visualization methods},
	doi = {10.1145/1287620.1287621},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-36048959880\&partnerID=40\&md5=a74cd76829bee9bb1cc21d6118e65340},
	author = {Akrivi Katifori and C. Halatsis and Giorgos Lepouras and Costas Vassilakis and E.G. Giannopoulou}
}
@conference {1154709,
	title = {A Comparative Study of Four Ontology Visualization Techniques in Protege: Experiment Setup and Preliminary Results},
	booktitle = {IV {\textquoteright}06: Proceedings of the conference on Information Visualization},
	year = {2006},
	month = {7},
	pages = {417{\textendash}423},
	publisher = {IEEE Computer Society},
	organization = {IEEE Computer Society},
	address = {Washington, DC, USA},
	abstract = {The continuing need for more effective information retrieval has lead to the creation of the notions of the semantic web and personalized information management, areas of study that very often employ ontologies to represent the semantic context of a domain. Consequently, the need for effective ontology visualization for design, management and browsing has arisen. There are several ontology visualizations available through the existing ontology management tools, but not as many evaluations to determine their advantages and disadvantages and their suitability for various ontologies and user groups. This work presents the preliminary results of an evaluation of four visualization methods in Protege.},
	isbn = {0-7695-2602-0},
	doi = {10.1109/IV.2006.3},
	author = {Akrivi Katifori and Elena Torou and C. Halatsis and Giorgos Lepouras and Costas Vassilakis}
}
@conference {Golemati200662,
	title = {A context-based adaptive visualization environment},
	booktitle = {Proceedings of the International Conference on Information Visualisation},
	year = {2006},
	note = {cited By (since 1996) 0},
	month = {7},
	pages = {62-67},
	abstract = {Digital libraries and historical archives are increasingly employing visualization systems to facilitate the information retrieval and knowledge extraction tasks of their users. Typically, each organization employs a single visualization system, which may not suit best the needs of certain user groups, specific tasks, or properties of document collections to be visualized. In this paper we present a context-based adaptive visualization environment, which embeds a set of visualization methods into a visualization library, from which the most appropriate one is selected for presenting information to the user. Methods are selected by examining parameters related to the user profile, system configuration and the set of data to be visualized, and employing a set of rules to assess the suitability of each method. The presented environment additionally monitors user behavior and preferences to adapt the visualization method selection criteria. Β{\textcopyright} 2006 IEEE.},
	keywords = {(PL) properties, Adaptive systems, Adaptive visualization, Behavioral research, Digital libraries, document collections, Extraction, Information analysis, Information science, Information services, Information systems, Information visualization, Knowledge extraction, Libraries, Retrieval (MIR), Search engines, Selection criterion, Set of rules, Solvent extraction, Specific tasks, System configurations, User behaviors, User groups, user profiling, Visualization, visualization methods, Visualization systems},
	doi = {10.1109/IV.2006.5},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-45149121827\&partnerID=40\&md5=ec45ad555b132faaf0bd2ca53e3292dc},
	author = {M. Golemati and C. Halatsis and Costas Vassilakis and Akrivi Katifori and Giorgos Lepouras}
}
@conference {DBLP:conf/icdim/TorouKVLH06,
	title = {Creating an Historical Archive Ontology: Guidelines and Evaluation},
	booktitle = {ICDIM},
	year = {2006},
	month = {12},
	pages = {102-109},
	abstract = {Ontologies have been proven invaluable tools both for the semantic web and for personal information management. In the context of a historical archive an ontology may provide meaningful and efficient support for search tasks as well as be used as a tool for storage and presentation of historical data. The creation however of such an ontology is complex, since the digitized archive documents are not in text format and the concepts that must be captured may vary among different time periods. This work presents a user-centric methodological approach for extracting the ontology of an historical archive focusing on the evaluation issues related to this process. The approach is exemplified through cases from its application in the University of Athens Historical Archive.},
	doi = {10.1109/ICDIM.2007.369337},
	author = {Elena Torou and Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and C. Halatsis}
}
@conference {1133365,
	title = {Visualizing a temporally-enhanced ontology},
	booktitle = {AVI {\textquoteright}06: Proceedings of the working conference on Advanced visual interfaces},
	year = {2006},
	month = {5},
	pages = {488{\textendash}491},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {Most ontology development methodologies and tools for ontology management deal with ontology snapshots, i.e. they model and manage only the most recent version of ontologies, which is inadequate for contexts where the history of the ontology is of interest, such as historical archives. This work presents a modeling for entity and relationship timelines in the Prot.g. tool, complemented with a visualization plug-in, which enables users to examine entity evolution along the timeline.},
	isbn = {1-59593-353-0},
	doi = {10.1145/1133265.1133365},
	author = {Akrivi Katifori and Costas Vassilakis and Giorgos Lepouras and I. Daradimos and C. Halatsis}
}
@article {DBLP:journals/eg/VassilakisLHL05,
	title = {An XML model for electronic services},
	journal = {Electronic Government},
	volume = {2},
	number = {1},
	year = {2005},
	pages = {41-55},
	abstract = {With the need for electronic services to be developed and deployed more and more rapidly, it is imperative that concrete models of electronic services are developed, to facilitate systematic work of electronic service stakeholders, concrete semantics and coherent representations across services developed within an organisation. Using the XML language to develop such a model, offers a number of additional advantages, such as rich semantics, facilitation of data interchange, extensibility, high abstraction levels and possibility for mechanical processing. In this paper we present the design aspects of an XML model for electronic services, which has been used for building a repository of interlinked elements representing e-services. A web-based interface for the management of this repository and a tool for automatically compiling e-service descriptions into executable images have been developed alongside. The model has been evaluated by a mixture of electronic service stakeholders, and the results of this evaluation are also presented.},
	doi = {10.1504/EG.2005.006647},
	author = {Costas Vassilakis and Giorgos Lepouras and C. Halatsis and Tomas Pariente Lobo}
}
@conference {Dimitrios00anapproach,
	title = {An Approach to Designing and Implementing Virtual Museums},
	booktitle = {Proceedings of the seventh UK VR-SIG Conference},
	year = {2000},
	month = {9},
	abstract = {The current paper describes an approach to designing and implementing a virtual environment comprising ten different museums. The number of museums as well as the variety of their exhibits lead to the adoption of a generalised strategy that catered for all museum presentation needs and allowed for future expansion. Furthermore, the system architecture supports the delivery of multimedia content either over the Internet or via a local immersive virtual reality installation.},
	author = {D. Charitos and Giorgos Lepouras and Costas Vassilakis and Akrivi Katifori and C. Halatsis}
}
