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Saha - Browser Based Semantic Annotation Tool

Page updated: 11.05.2011

User-interface of SAHA Saha is a browser-based annotation tool, which can be used to annotate e.g. web-pages and other documents on the web. With Saha, annotation process can be easily distributed and it can be used without installing any annotation software on user's computer.

Annotations are stored in a database, from which they can be retrieved for use in semantic applications, like portals using multi facet search paradigm. Saha uses semantic web technologies such as OWL and RDF(S).

Saha's user-interface consists of property-input-form, which can be easily configured for the annotation-schema being used. Different kinds of resources can be used as values of the properties:

  • Resources defined in external ontologies and fetched to the annotation using the Onki Ontology Library Service
  • Resources defined in other external sources, such as CultureSampo
  • Instances of classes defined in the annotation-schema
  • Literal values

Saha has undergone several major development versions. Demo of the current Saha (SAHA3) is available here. Please note that while browser interoperability is a design goal, some advanced features might not work properly in older versions of Internet Explorer.

Saha (SAHA3) is open source software and published in Google Code under the MIT license for open collaboration.

Basic documentation about Saha is available in the Saha Technical Report



Jussi Kurki and Eero Hyvönen: Collaborative Metadata Editor Integrated with Ontology Services and Faceted Portals. Workshop on Ontology Repositories and Editors for the Semantic Web (ORES 2010), the Extended Semantic Web Conference ESWC 2010, Heraklion, Greece, CEUR Workshop Proceedings, http://ceur-ws.org/, June, 2010. bib pdf


Onni Valkeapää, Olli Alm and Eero Hyvönen: Efficient Content Creation on the Semantic Web Using Metadata Schemas with Domain Ontology Services (System Description). Proceedings of the European Semantic Web Conference ESWC 2007, Innsbruck, Austria, Springer, June 4-5, 2007. bib pdf
Onni Valkeapää, Olli Alm and Eero Hyvönen: A Framework for Ontology-based Adaptable Content Creation on the Semantic Web. Journal of Universal Computer Science, 2007. bib pdf
Creation of rich, ontology-based metadata is one of the major challenges in developing the Semantic Web. Emerging applications utilizing semantic web techniques, such as semantic portals, cannot be realized if there are no proper tools to provide metadata for them. This paper discusses how to make provision of metadata easier and cost-effective by an annotation framework comprising of annotation editor combined with shared ontology services. We have developed an annotation system supporting distributed collaboration in creating annotations, and hiding the complexity of the annotation schema and the domain ontologies from the annotators. Our system adapts flexibly to different metadata schemas, which makes it suitable for different applications. Support for using ontologies is based on ontology services, such as concept searching and browsing, concept URI fetching, semantic autocompletion and linguistic concept extraction. The system is being tested in various practical semantic portal projects.


Onni Valkeapää and Eero Hyvönen: A Browser-based Tool for Collaborative Distributed Annotation for the Semantic Web. September 26, 2006. 5th International Semantic Web Conference, Semantic Authoring and Annotation Workshop, November, 2006. bib pdf
Onni Valkeapää: Verkkoresurssien ontologiaperustainen annotointi. MSc Thesis, Helsinki University of Technology, September, 2006. bib pdf
Onni Valkeapää and Eero Hyvönen: Semantic Annotation with Browser-based Annotation Tool SAHA. July 17, 2006. Demo paper, 1st Asian Semantic Web Conference (ASWC2006). bib pdf
Onni Valkeapää and Eero Hyvönen: A Browser-based Semantic Annotation Tool for Distributed Content Creation. June 16, 2006. Poster paper, 1st Asian Semantic Web Conference (ASWC2006). bib pdf

Contact person:

Jussi Kurki
University of Helsinki

Prof. Eero Hyvönen
Helsinki University of Technology, Laboratory of Media Technology and University of Helsinki
eero.hyvonen [at] tkk.fi

/m/fs/seco/www/www.seco.tkk.fi/include/secoweb/utils.php; Tue, 28 Mar 2017 11:07:41 +0300