The QALL-ME Framework is a reusable architecture skeleton for building question answering systems. Question answering is an advanced type of information retrieval (IR) which for given natural language questions returns appropriate answers. See section 2.2.1: “Target Audience” for decision guidance on whether the QALL-ME Framework might be interesting for your purposes.

The QALL-ME Framework has been designed with multilingual capabilities in mind. This means that questions can be posed in several different natural languages like German, Italian or English. Answers can be retrieved from structured data sources like databases or simply XML documents. Answers can even be retrieved crosslingually, i.e., the language of the answer documents needn’t equal the language of the input question. Check out the detailed overview in section 2.1 for more information on these features.

The QALL-ME Framework is based on a Service Oriented Architecture which is implemented using standard web service technology for the service components. Therewith the framework inherits the advantages of service oriented architectures, such as easy reuse of existing components. Section 2.1.6: “Service Oriented Architecture” provides all the details on this.

QA systems which are built with the QALL-ME Framework are targeted at a specific domain, i.e., at a certain area like tourism or science. The answer data for this domain has to be modeled according to an ontology which is a formal representation of the conceptual knowledge of the domain. Again, have a look at the system architecture in section 2.1.3 for further information on how ontologies are integrated into the overall framework.

The critical spot in every QA system is to find the mapping between the information need from the question and possible answer documents. To solve this problem the QALL-ME Framework utilizes textual entailment components for every question language. In general these components allow a machine to find out whether a given hypothesis sentence is semantically contained in another piece of text. If you are wondering how this capability can be applied to question answering, then you should head over to section 2.1.5 for a detailed explanation of this central idea.

Releasing a piece of software as “open source” is not just about releasing code to the public, especially not if the software is a framework that other developers are supposed to build on. Probably you already have seen open source initiatives of other projects that have been fruitless although providing good software; the problem being that this software is completely inaccessible to other developers or users because of the lack of sufficient documentation. To make a difference, a major part of the QALL-ME Framework is substantial documentation. Now that you are reading this you have already found your way to this documentation.

The best documentation may be useless if one doesn’t know what the actual outcome shall look like or if the entrance barrier for trying out a software product is too high. Therefore the QALL-ME Framework ships with working demo components that can be customized and used for testing. In addition there are step-by-step guides to easily get you started with common tasks in the framework. All this can be found in section 3: “Tutorials”.

The QALL-ME Framework seeks to be compliant with standards as far as possible. In general this standards compliance enhances interoperability; in particular this may be a smooth integration of the framework into existing environments, a quick integration of existing components into the framework or even just an easier understanding of existing code for new developers. Amongst the standards that the QALL-ME Framework supports are for example web standards like WSDL, SPARQL, OWL or RDF but also rather generic standards such as RFC 3066. Section 2.2 provides a coarse overview of what standards you should be familiar with in order to efficiently use the framework.

The QALL-ME Framework is not just open source but it is also free software, i.e., you are free to modify, extend and use the framework according to the terms of the Apache License 2.0. Despite its rather young age, the framework has already gained high potential for application in production systems, i.e., its quality is being evaluated in an industrial project: Comdata S.p.A. and FBK – both members of the QALL-ME project consortium (cf. section 2.4: “By the Way: What is QALL-ME?”) – are currently developing a QA system for the tourism domain. This system is based on the QALL-ME Framework and strives to open up new market segments with bleeding edge NLP technology.

The QALL-ME Framework has gotten its name from the EU funded QALL-ME project. The project is driven by four international language technology research institutes and three companies. As with every EU project, quality is assured through independent reviewers and evaluations. More information on the roots of the QALL-ME Framework can be found in section 2.4.