Goal Formulation based on Communicative Principles

The paper presents the Constructive Dialogue Model as a new approach to formulate system goals in intelligent dialogue systems. The departure point is in general communicative principles which constrain cooperative and coherent communication. Dialogue participants are engaged in a cooperative task whereby a model of the joint purpose is constructed. Contributions are planned as reactions to the changing context, and no dialogue grammar is needed. Also speech act classification is abandoned, in favour of contextual reasoning and rationality considerations.

Introduction
Two general approaches can be distinguished in dialogue management: the structural approach, which uses a dialogue grammar to capture regularities of the dialogue in terms of exchanges and moves (Bilange, 1992;Cawsey, 1993;Grosz and Sidner, 1986), and the intention-based approach, which classifies the speaker's beliefs and intentions into speech acts, and uses planning operators to describe them (Appel% 1985;Allen and Perrault, 1980;Bunt et al., 1984). Both regard natural language as purposeful behaviour, but differ in how this behaviour is to be described. The former sees dialogues as products and compiles participants' beliefs and intentions into a predefined dialogue structure, whereas the latter focusses on the participants' goals, and hides the structure in the relations between acts which contain appropriately chosen sets of beliefs and intentions as their preconditions and effects.
We will not go into detailed evaluation of the approaches, see e.g. (Jokinen, 1994), but draw attention to three aspects of dialogues which have *I am grateful to Yuji Matsumoto for providing an excellent resem'ch environment during my JSPS Postdoctoral Fellowship, and Graham Wilcock for helpful discussions.
not been properly addressed before, although widely acknowledged in literature, and important in building robust Natural Language interfaces: 1. dialogue is a collaborative process and its structure is recognised by external observation, not prescribed as an internal constraint of dialogue management (Sacks et al., 1974;Clark and Wilkes-Gibbs, 1990), 2. the speakers' beliefs and intentions in a given dialogue situation are various, and cannot all be checked when deciding oil the next response (Cherniak, 1986), 3. communicative acts are part of social activity, constrained by normative obligations of rational agency (Allwood, 1976).
We discuss these aspects from the point of view of cooperative goal formulation and present the Constructive Dialogue Model as a new approach to plan system responses. Our departure point is in general conmmnicative principles which constrain cooperative and coherent communication, and radical steps are taken in two respects: the dialogue grammar is abandoned as an infeasible way to describe dialogues, and also speech act recognition is abandoned as a redundant labelling of intention configurations. The first step means that the structure is not built according to structuring rules, but emerges from local coherence as the dialogue goes on. The second step means that beliefs and intentions are dealt with by reasoning about the utterance context and communicative constraints instead of speech act types. The decision about what to say next falls out as a result of the agent complying with the communicative principles which refer to the agent's rationality, sire cerity, motivation and consideration. Combined with contextual knowledge, they account for the acceptability of different alternative responses.
The paper is organised as follows. The theoretical framework and its formalisation as the Constructive Dialogue Model are discussed in Section 2. Section 3 presents how the system's communicative goal is determined, and Section 4 provides comparision with related work. Finally, conclusions and filture directions are given in Section 5.  (Allwood, 1976) in comimmication: (1) assume a joint l)urpose, (2) show cognitive consideration (epistemic rationality regarding appropriate ways to react) and ethical consideration (intention to react in a way that does not prevent the partner fi'om fiflfilling her goals), and (3) trust, that the partner is acting according to the same principles. Ideal cooperation does not mean that the agents always react in the way the partner intended to evoke, but rather, it sets the normality assumptions for the way the agents would behave if no disturbing factors were present. As (Galliers, 1989) points out, conflict resolution forms an important part of human conmmnication, and if systems are always ready to adopt the user's role, they becolne rigid and unrealistic. However, if the conflict becomes so serious that it makes any cooperation impossible, communication will break down as well. Rational agents thus try to conlnlunicate so as to conforln to the shared assumptions about operationally appropriate and ethically acceptable acts in a given situation (Jokinen, 11995). Empirical dialogue research has emphasised collaborative nature of dialogues (Sacks et al., 1974;Clark and Wilkes-Gibbs, 1990). Also computationally oriented dialogue studies show that the users express themselves vaguely and continue with follow-up questions (Moore and Paris, 1993), and our corpus 1 supports the view that even sin> ple information seeking dialogues resemble negotiations rather than straightforward question-answer sequences. Based on these obeservations and the theoretical assumptions of Ideal Cooperation, we distinguished the main factors in rational, cooperative dialogue management as follows: Surface form Expressive intentions Declarative express a belief: want (Sp ,know(He ,P) ) Interrogative desire for information: want (Sp,know(Sp, P) ) hnperative desire for action: want (Sp,do(ge,P)) Exclamative express action:

want (Sp, do (Sp,P))
whereas the information seeker is not expected to teach the information provider how to look for the information. The roles can be further difl'erentiated with respect to social factors such as acquaintance of the addressee and fornlality of the situation. • Communicative obligations. Social, normative requirements that concern the agent's sincerit'9 (exchange information which is true or for which evidence can be provided), motivation (exchange information which is related to one's goals and strategies), and consideration (exchange information which the. partner is able to deal with). • Task. Gives rise to communication. Task goals are planned to complete a real workt task (rent a car, book ~ flight, repair a pump) but because of uneven distribution of knowledge, the agents usually need to collaborate to achieve the goal, and thus formulate com-,nunicative goals to obtain missing information, el. (Guilm, 1994). B. Commmficative act: • Expressive and evocative attitudes. To distinguish between the effects of an utterance and the intentions behind it, Austin's concept of illocution is split up into two: ezpvession of the speaker's attitude and evocation of a reaction in the partner; perlocution corresponds to what is actually achieved by the act: the evoked respoT~se, cf. (Allwood, 1976). Expression may differ fl'om evocation (irony, indirectness), aud the evoked response fi'om the evocative intentions (the agent requests ilfformation that the partner cannot or does not want to disclose; the agent fa.ils to fi'ighten the partner becmme this has guessed the agent's malicious intentions).

A. Communicative situation: C. Communicative context:
• Role. Characterised by global communica-• Expectations. Evocative intentions put live rights and obligations of the agents. E.g. the information provider is expected to give information which is relevant for the task, 1The corpus was collected by the Wizard-of-Oz technique with users trying to find information on car-[tire companies and restaurants in a particular area, and is reported in (Nivre, 1992). pressure on the agent to react in a particular way. Conventional expectations, carried by the surface form ( Fig. 1), serve as anchoring points in reasoning about the partner's communicative goal (Cohen and Levesque, 1990). Initiatives. If the agent has initiated a con> municative goal, she "has the initiative" and also the right to pursue the goal until it is achieved or not relevant anymore. She also has the right to expect the partner to collaborate or at least not prevent the agent from achieving her goal. • Unfulfilled goals. If the expressive attitudes of the partner's response match the evocative intentions of the agent's contribution, the communicative goal of the agent's contribution is fulfilled. An unfulfilled goal is pushed forward or stored for later processing.
When the agent has the right to take the initiative, a previously unfulfilled goal can be taken up. If the goal is still unfulfilled and relevant, it is resumed, otherwise dropped. • Thematic coherence. A competent agent relates the topic of her contribution to what has been discussed previously or marks an awkward topic shift appropriately; otherwise the agent risks being understood. Thematic relatedness is based on the types of relationships which occur in the domain.

The CDM System
The theoretical framework is formalised as an approach to dialogue management called the Constructive Dialogue Model, CDM (Jokinen, 1994).
In CDM, the dialogue is an instrument to exchange new information on a particular topic to complete a real world task, and it is managed locally by reacting to the changed dialogue context. The task division and information flow in a CDM system 2 is shown in Fig. 2. The dialogue manager operates on the Context Model which is a dynamic knowledge base containing facts about the agents' goals, expressive and evocative attitudes, central concepts (topic), and new information. It also has access to three static knowledge bases: Communicative Principles (knowledge about rational, cooperative communication), Application Model (knowledge about tasks and roles), and World Model (general knowledge about the entities and their relations in the world). 3 Dialogue contributions are constructed in three phases corresponding to the three main processing tasl~s. Analysis of the input message results in the user's communicative goal, and contains four subtasks: determine the explicitness level, interpret the propositional content, check coherence and verify obligations. Evaluation of the user goal concerns an appropriate joint purpose and determines the next system goal. Response specifies the system's communicative goal up to the semantic representation using the same subtasks as analysis but in a reverse order. Evaluation and response form the agent's reaction.
2The prototype is implemented in SICStus Prolog 2.1, running under UNIX TM on a Sun SPARCStation.
3 Linguistic knowledge is encoded in a linguistic lexicon and grammar, and not discussed here.  The Context Model is represented as a partitioned Prolog database and the predicates have an extra argument referring to the contribution whose processing introduced them. In the attitude language the predicates know, want and do represent belief, intention and action, respectively, s refers to the system and u to the user. Communicative Principles are reasoning rules of the fort0: if cntxtFactl .... , cntxtFactN then cntxtFactM+1,...,cntxtYactK.
The World Model uses neo-Davidsonian event representation, and the Application Model provides mappings from World Model concepts to task and role related facts.

3
Cooperative Goal Formulation In CDM, joint purpose represents the communicative strategy that an agent has chosen in a particular situation to collaborate with her partner. It is determined by evaluating the partner's goal with respect to the communicative context: expectations, initiatives, unfulfilled goals and coherence.
Assigning binary values to these aspects, we get 2 4 = 16 joint purposes, summarised in Fig. 3. The The joint purpose describes coinnmnieative intentions in a context where no speaker obligations or considerations hold. In order to attend the requirements of a particular communicative situation, the joint purpose needs to be specified with respect to the agent's role, task and communicative obligations.
Specification of the joint purpose via the Application Model captures the cognitive consider= ation of Ideal Cooperation: the agent plans her response to be operationally appropriate in the current situation. The result is a communicative goal (c-goal), a set of communicative intentions instantiated according to the current task and role.
The c-goal is then filtered through communicative obligations which impleinent the ethical consideration of Ideal Cooperation: the agent's communicative competence shows in the ways she can realise the same c-goal in various situations. Some communicative obligations are listed in Fig. 4.
Sincerity: "do I know this or can provide evidence?" 1. Everything that the speaker asserts or implies is true unless otherwise explicitly stated.
Motivation: "can I say this?" 1. Everything that the speaker wants to know or wants the partner to do is motivated except if the speaker cmmot take the initiative on it. 2. Everything that addresses what the partner wanted to know or wanted the speaker to do is motivated, except if the speaker emmot disclose the information or do the act. 3. Everything that is related to CC is motivated if not already known. 4. Everything that informs of inconsistency is motivated if not already known.
Consideration: "may I say this?" 1. If the partner's goal cammt be fulfilled (presuppositions are false, facts contradictory, no information exists), it is considerate to inform why (explain, compensate, initiate repair). 2. If the response would repeat previous information, it is considerate to leave this implicit unless the information is assigned a special emphasis. 3. If the partner's response is unrelated, it is considerate to inform of the irrelevance, given that the speaker has unfulfilled goals. 4. [f the partner did not request a piece of related information, it is considerate to include this explicitly in the response, given that the speaker intends to close the topic.

Example
Consider the following sample dialogue where tile system's task is to provide service information to the user: Uh I need a car. $1: Do yon want to buy or rent one? Ui: Rent. $2: Where? U3: In Bolton. $3: OK. ttere are the car hire companies in Bolton: ....
The analysis of the first user contribution U1 is given in Fig. 5. The content of the user's c-goal is inferred from the World Model which says that 'needing a car' can be interpreted as 'wanting to have a cl~r'.
NEW INPO: needE(n,u,c), user(u), car(c) USER C-GOAL: want (u, want(s, know(s, [want~e E(h, u, e )]) )) CENTRAL CONCEPT: needE (n,u,c) EXPRESSIVE ATTITUDES: intention: user intend that system know P: want (u, know(s,[needE(n,u, c ), user(u), car(c)])) assumptions: user know that system not know P: know (u, not know(s,[needE(n,u,d, user(u),car(e)])) EVOCATIVE ATTITUDES: intention: user intend that system intend that system know P: want (u, want#, know(s, [.eed E(n, u, c ), user(u ), ear(c)]))) want (u, want(s, know(s,[wantHave E(h,u,c )], user(u ),~a,'(~ )]) ) ) In the beginning of the dialogue the system has no unfulfilled goals, and its role as an obedient information provider does not allow it to have the initiative. Moreover, any contribution is trivially unrelated to the previous topic, since no previous topic exists. According to the Joint Purpose rule (2), the user's c-goal is thus adopted, and the system also takes the initiative, since the user contribution is non-expected (an information seeker is expected to start with a question or a request).
The joint purpose becomes new-indir-request with "user wants to have a car" as the content, i.e. the communicative strategy is to share the user's want to have a car, and check if this want can be satisfied within the Application Model.
The system cannot provide the user with a car, but it can provide information about the services that, enable the user to have a car. Application Model lists car hire companies and car garages as possible services, so the communicative goal is formulated as to know which is the preferred service. The services are associated with renting or buying cars, thus the disjunction is realised as 5'1.
The system responses $2 and 5"3 are based on the same strategy baclcto: the system 'goes back' to adopt the user's previous unfulfilled goal and tries to satisfy this in the updated context. 4 However, they carry different c-goals due to different specification in the Application Model: $2 aims at narrowing down the database search, 5,3 completes the original task. Finally, the communicative obligation Consideration (4) requires that the application service (car hire company) and location (Bolton) are explicitly expressed in $3 before the list of services.
4The user response fulfills expectations and is themaritally related, and the system has the initiative and unfulfilled goals, at least one based on the original task to provide information.

Discussion and related work
In Section 1 we pointed out three important aspects of dialogues which have been insufficiently accounted for in the earlier approaches to dialogue management. In CDM, these aspects form the basis of the system's functionality: dialogues are regarded as collaborative activities, planned locally in the changed context as reactions to the previous contributions and governed by the rationality principles of Ideal Cooperation. The logical omniscience assumption is tackled by partitioning the Context Model and focussing on specific knowledge with the hel f ) of thematic coherence; also rationality considerations constrain reasoning.
By adhering to general communicative principles, CDM provides a new and uniform way to treat various phenomena that have been separately studied in previous research: goal formulation, coherence and cooperativeness. Communicative principles fimetion on the following levels:

Determination of the joint purpose:
reasoning about a communicative strategy in the context (expectations, initiatives, unflflfilled goals, thematic coherence) 2. Selection of the communicative goal: filtering the joint purpose with respect to the agent's role and task. 3. Realisation of the goal: specifying the goal in regard to the communicative obligations sincerity, motivation and consideration.
However, we also use insights from the huge body of research that exists on dialogue management and natural language planning. For instance, the negotiative nature of dialogues is emphasised in (Moore and Paris, 1993) who show how rhetorical knowledge can be combined with the knowledge about the speaker's intentions and communicative goals so that the system can understand follow-up questions or justify its explanations.
Our work differs from this in that we study general requirements of communication rather than rhetorical relations and their augmentation with speaker intentions, to determine @propriate responses. It is possible to modify our joint purpose algorithm with information about rhetorical relations so as to check expectations in regard to argmnentation, or to include rhetorical knowledge in the obligations used when reasoning about multisentential contributions, but as our primary goal has been to specify communicative principles and use them in the formalisation of the cooperative and rational nature of dialogues, this kind of extension is left for future. (Guinn, 1994) presents a model of mixedinitative negotiation as collaborative problem solving. His Missing Axiom approach demonstrates collaboration and communication between two agents wl~o possess complementary knowledge: if the agent's information is not sufficient to allow completion of the proof the agent is set to do, the agent attempts to provide the missing axioms through interaction. This is similar to our basic assumption of how domain tasks give rise to eonlinunication. The differences lie again in our einphasis on 'Rational and Cooperative Communication' as opposed to 'Interaction as a FMlure to Prove'.
In abandoning dialogue grammar and speech act classification, we agree with the common view currently held among researches: dialogue structure is constructed on the basis of the participants' beliefs and intentions, and speech act types are at most convenient abbreviations for a set of attitudes held by the speakers, but do not constitute an explanation of the dialogue (Cohen and Levesque, 1990;Galliers, 1989). We Mso use contextual knowledge extensively, and connect intention-based approaches to practical dialogue management: rationality and cooperation are not only tied to the agent's beliefs and intentions of the desidered next state of the world, but also to the wider social context in which the communication takes place.

Conclusion and future directions
This paper has presented a new way to formulate system goals in intelligent dialogue systems. It advocates a view-point where the system's fnnctionality is iml)roved by relating the dialogue situation to communication in general. The constraints of rational, cooperative communication p,:ovide the framework in which to deal with contributions: communicators have a joint purpose, they obey communicative obligations and they trust that the partner behaves so that these constraints are tifffilled. Dialogues are dynamic constructions, and contributions are locally planned and realised so that the communicative requirements of the dialogue us a whole are respected.
Current interests concern the extension of the communicative principles into different activities and agent roles. This contributes to the generality of the model by spelling out specific requirements of different communicative situations. It also enables us to study strategic planning and how different roles affect the obligations that the agents want to obey (e.g. in conflict situations). Work is now in progress to cover other types of task dialogues, and to enhance the impleinentation.


The state of machine translation in Europe

This first half of this general survey covers MT and translation tools in use, including translators workstations, software localisation, and recent commercial and in-house MT systems. The second half covers the research scene, multilingual projects supported by the European Union, networking and evaluation. In comparison with the United States and elsewhere, the distinctive features of activity in Europe in the field of machine translation and machine-aided translation are: (i) the development and popularity of translator workstations, (ii) the strong software localisation industry, (iii) the vigorous activity in the area of lexical resources and terminology, (iv) and the broad based research on language engineering supported primarily by European Union funds. 1. Translator's workstations Recent years have seen great advances in the development and exploitation of support tools for translator. The four most widely used translator's workstations originate from Europe: Trados' Translation Workbench, IBM's TranslationManager, Eurolang's Optimizer, and STAR's Transit. In addition, Europe has been the centre for most of the background and current research on workstations: the TWB project funded by the European Union, and the Commission's own EURAMIS project. For professional translators, the attraction of the workstation is the integration of tools from simple word processing aids (spelling and grammar checkers) to full automatic translation. The translator can choose to make use of whichever tool seems most appropriate for the task in hand. The vendors of these systems always stress that translators do not have to change their work patterns; the systems aim to increase productivity with translator-oriented tools which are easy to use and fully compatible with existing word processing systems. In facilities and functions, each offer similar ranges: multilingual split-screen word processing, terminology recognition, retrieval and management, translation memory (pre-translation based on existing texts), alignment software for users to create their own bilingual text databases, retention of original text formatting, and support for very wide range of European languages, both as source and target languages. Integration to MT systems is now provided by three of the workstations. In the case of Trados access is provided to the Transcend software from Intergraph; IBM Translation Manager links up with Systran; and Eurolang Optimzer with Logos. After its disappointing experience with Eurotra, the European Commission has devoted most of its research support to the development of practical tools for translators and to the creation of essential lexical resources. Most of these projects will be described later. A major project was the TWB (Translator's Work Bench) project -within the ESPRIT framework -which began in 1989 and ended in 1994. The project, led by Triumph-Adler and involving 10 members from companies and universities, investigated the requirements of translators and proposed most of the features which are now commonplace in translator workstations: multilingual editor, document converters, access to lexica and terminology databases (e.g. Eurodicautom), access to MT systems (in this case, METAL), tools for term bank building, pre-translation and translation memory, and in particular a tool kit (System Quirk) for the analysis of texts and the development of lexical resource databases (thesauri, knowledge bases) from corpora and term banks. (A full description of the TWB project has recently been published: Kugler et al. 1995). A second project in this area has been TRANSLEARN, an LRE project for an interactive corpusbased translation drafting tool (a prototype translation memory system) based on EU regulations and directives from the CELEX (European Union law) database. The languages involved have been English, French, Portuguese and Greek. A third project, this time funded by Volkswagen, is investigating the use of a domain knowledge base integrated with a linguistic database as a translation tool; the languages are German and Bulgarian. The Translation Service of the Commission itself is now developing its own workstation: EURAMIS. The aim is to optimize the efficiency of the translation resources already available (e.g. the termbank Eurodicautom), to create a database of translated EU documents (as a 'translation memory'), and to provide easy access to MT systems. It will allow individual translators to develop their own tailor-made resources and facilities, with tools for text corpus management, glossary construction, and text alignment. A particular emphasis will be on the integration of MT and translation tools, including the mutual enrichment of Systran dictionaries and Eurodicautom lexical databases. The European strength in the area of terminology continues. A recent list of termbanks from InfoTerm in Vienna reveals that over two thirds of the 100 terminological databases recorded are based in Europe. The links between terminologists and translators have been a marked feature on the European scene -links which are now extending to the MT community. Terminology and the lexicon was the topic of an EAMT workshop in 1993 (Steffens 1995), and this August another EAMT workshop was held in conjunction with the international terminology conference in Vienna.

Translator's workstations
Recent years have seen great advances in the development and exploitation of support tools for translator. The four most widely used translator's workstations originate from Europe: Trados' Translation Workbench, IBM's TranslationManager, Eurolang's Optimizer, and STAR's Transit. In addition, Europe has been the centre for most of the background and current research on workstations: the TWB project funded by the European Union, and the Commission's own EURAMIS project.
For professional translators, the attraction of the workstation is the integration of tools from simple word processing aids (spelling and grammar checkers) to full automatic translation. The translator can choose to make use of whichever tool seems most appropriate for the task in hand. The vendors of these systems always stress that translators do not have to change their work patterns; the systems aim to increase productivity with translator-oriented tools which are easy to use and fully compatible with existing word processing systems. In facilities and functions, each offer similar ranges: multilingual split-screen word processing, terminology recognition, retrieval and management, translation memory (pre-translation based on existing texts), alignment software for users to create their own bilingual text databases, retention of original text formatting, and support for very wide range of European languages, both as source and target languages. Integration to MT systems is now provided by three of the workstations. In the case of Trados access is provided to the Transcend software from Intergraph; IBM Translation Manager links up with Systran; and Eurolang Optimzer with Logos.
After its disappointing experience with Eurotra, the European Commission has devoted most of its research support to the development of practical tools for translators and to the creation of essential lexical resources. Most of these projects will be described later. A major project was the TWB (Translator's Work Bench) project --within the ESPRIT framework --which began in 1989 and ended in 1994. The project, led by Triumph-Adler and involving 10 members from companies and universities, investigated the requirements of translators and proposed most of the features which are now commonplace in translator workstations: multilingual editor, document converters, access to lexica and terminology databases (e.g. Eurodicautom), access to MT systems (in this case, METAL), tools for term bank building, pre-translation and translation memory, and in particular a tool kit (System Quirk) for the analysis of texts and the development of lexical resource databases (thesauri, knowledge bases) from corpora and term banks. (A full description of the TWB project has recently been published: Kugler et al. 1995).
A second project in this area has been TRANSLEARN, an LRE project for an interactive corpusbased translation drafting tool (a prototype translation memory system) based on EU regulations and directives from the CELEX (European Union law) database. The languages involved have been English, French, Portuguese and Greek. A third project, this time funded by Volkswagen, is investigating the use of a domain knowledge base integrated with a linguistic database as a translation tool; the languages are German and Bulgarian.
The Translation Service of the Commission itself is now developing its own workstation: EURAMIS. The aim is to optimize the efficiency of the translation resources already available (e.g. the termbank Eurodicautom), to create a database of translated EU documents (as a 'translation memory'), and to provide easy access to MT systems. It will allow individual translators to develop their own tailor-made resources and facilities, with tools for text corpus management, glossary construction, and text alignment. A particular emphasis will be on the integration of MT and translation tools, including the mutual enrichment of Systran dictionaries and Eurodicautom lexical databases.
The European strength in the area of terminology continues. A recent list of termbanks from InfoTerm in Vienna reveals that over two thirds of the 100 terminological databases recorded are based in Europe. The links between terminologists and translators have been a marked feature on the European scene --links which are now extending to the MT community. Terminology and the lexicon was the topic of an EAMT workshop in 1993 (Steffens 1995), and this August another EAMT workshop was held in conjunction with the international terminology conference in Vienna.

MT in use
As many observers have commented the take-up of MT systems in Europe has been much slower than expected; markets are small and fragmented, and professional translators remain hostile. The potential is enormous, but far from being exploited. MT systems are used primarily by large translation services and by multinational companies. Smaller organisations favour translation workbenches, sometimes networked for sharing term databases and translation memories; and increasingly workstations are being considered by individual freelance translators. The cheaper PC-based systems are generally only of interest to those with occasional translation needs, and still not being purchased on the scale apparent in North America or Japan.
Some of the more notable recent installations in multinational companies to mention are: Ericsson, where the Logos system is providing 10% of translation needs (for producing manuals and documentation in French, German and Spanish); SAP, using Metal for German-English translation and Logos for English-French (totalling some 8 million words in the current year); and Siemens, providing a service based on Metal.
At the European Commission, the use of Systran continues to grow, now amounting to some 200,000 pages per year. The main users are non-linguist staff needing translations for information purposes (short-lived and/or repetitive documents), and drafts for writing documents in non-native languages. The increased use is attributable to improved interfaces and access tools. For translators the main development is EURAMIS.
However, perhaps the most distinctive feature of the European scene is the growth of companies providing software localisation. These services are acquiring considerable experience in the use of translation aids and MT systems (e.g. Logos, Metal and XL8). As a forum for the interchange of experience and the establishment of standards the Localisation Industry Standards Association was set up in 1990; the association publishes a newsletter (LISA Forum) and has produces a CD-Rom directory of products, standards and methods (LISA Showcase). A major centre for localisation is Ireland, which since 1994 has its own Software Localisation Group, holding conferences and workshops and recently setting up a Localisation Resources Center (with support from the Irish government and EU.)

Commercial systems
In comparison with the United States and Japan, there have been surprisingly few MT systems developed and manufactured by European organisations. Two come from the former Soviet Union. From St Petersburg comes the very successful PC-based Stylus Russian-English, English-Russian, and German-Russian systems oriented primarily to business correspondence. Sales have been good in both East and West Europe. From Kharkov (Ukraine) come the PARS systems for Russian and Ukrainian to and from English, with sales mainly in the Ukraine and East Europe.
In Germany, changes in organisation have affected the development of Metal in recent years, however it is now available as a client/server system on Unix workstations and PCs, and as a network service for occasional users. Best developed remains the German-English system, but other languages have now been released: German-Danish, French-English, English-Spanish, and work is reported on Catalan, Italian, Portuguese.
The most recent entrant from Germany is the Personal Translator, a joint product of IBM and von Rheinbaben & Busch, based on the LMT (Logic-Programming based Machine Translation) slot-grammar transfer-based system under development at IBM since 1985. LMT itself is available as an MT component for the IBM Translation Manager. The Personal Translator is a PC-based system and intended primarily for the non-professional translator (consultants, secretaries, technicians) and competing therefore with Globalink and similar products. At present the languages are German and English in both directions.
Other less sophisticated PC-based systems include the following: from Italy there is Hypertrans, developed initially for translating patents in Italian and English, then expanded to include other European languages (French and German, Spanish) and currently used to translate patent abstracts for the European Patent Office, and now sold for wider general purposes; from France there is the Al-Nakil system for translating between Arabic, French and English; and from Denmark there is the PC-based Winger system for Danish-English, French-English and English-Spanish, now also marketed in North America, and the TranSmart system for Finnish-English from Kielikone Ltd.

Custom-built systems
Both Winger and TranSmart were initially built for specific customers. In the case of TranSmart, this was developed originally as the Kielikone translation workstation for Nokia Telecommunications. Subsequently, versions were installed at other Finnish companies and the system is now being marketed more widely.
A similar story applies to GSI-Erli. This large language engineering company developed an integrated in-house translation system combining an MT engine and various translation aids and tools on a common platform AlethTrad. Recently it has been making the system available in customised versions for outside clients.
Custom-built MT has become a speciality of Cap Volmac Lingware Services, a Dutch subsidiary of the Cap Gemini Sogeti Group. Over the years this software company has constructed controlled-language systems for textile and insurance companies, mainly from Dutch to English.
The Dutch language has also been the focus of an in-house system built at Hook & Hatton, in this case initially for the translation of documents in chemical engineering, but now as a commercial MT service for industrial customers in other subject fields. Begun as a simple pattern matching method to find frequently recurring phrases, the system added a terminology database and simple grammar rules and is now an efficient low-cost low-quality MT system.
In recent years, probably the best known success story for custom-built MT is the PaTrans system developed for LingTech A/S to translate English patents into Danish. The system is based on methods and experience gained from the Eurotra project of the European Commission.
Nearly all the successful applications of MT and the in-house systems are based on the control of input texts. Research on this area of 'language engineering' has been strong in recent years in Europe. The SECC project in Leuven, supported by Siemens Nixdorf, Cap Gemini Innovation and Sietec is using MT methodology as the basis for a tool for writing in a controlled language, Simplified English; the Metal system is effectively translating English into the controlled language.
Earlier this year, the University of Leuven organised a conference on controlled languages, the first devoted exclusively to this theme (CLAW, 1996). Participation was international, but European research was strongly represented with 16 of the 22 contributions; the majority on controlled English, but also German and Swedish represented.

Research on MT
It is undeniable that MT research in Europe has quantitatively declined since the ending of the Eurotra project (officially in 1992, but effectively some years earlier). The failure to produce a working system has been attributed mainly to the over-emphasis on linguistic formalism, the neglect of the lexical databases, and the absence of industrial participation. Nevertheless, it is agreed that the project did create in Europe a strong research community in language engineering which was able to successfully collaborate cross-nationally.
Eurotra itself has however brought forth a number of continuations. One has been mentioned already: PaTrans. Another is the CAT2 system at Saarbrücken, an experimental platform (a stratificational transfer-based unification grammar system) which is the MT engine for the EUfunded (LRE) project ANTHEM. The prototype is to be a multilingual interface for natural language input and retrieval of medical diagnoses. The sublanguage system is based on the analysis of a Dutch and French corpus from the Belgian Army and on the widely used Systematised Nomenclature of Human and Veterinary Medicine.
Another by-product of Eurotra is the KIT-FAST system, an experiment in knowledge-based MT with an emphasis on tackling problems of anaphora and the representation of communication functions.
Two research groups are investigating MT systems where control of the input is the result of user-computer dialogue: monolinguals compose messages interactively in their own language and translation into an unknown target language is performed automatically. At the University of Manchester Institute of Science and Technology the experimental system is based on the 'pure' implementation of an example-based approach. At the University of Grenoble, the LIDIA system involves interactive disambiguation and reverse translation into the user's language.
Other research efforts are taking place at ISSCO (Geneva) within a unification grammar framework on a sublanguage system for avalanche warnings, at the Sharp Laboratories of Europe (Oxford) on the shake-and-bake model of MT, at the Institute for Information Transmission Problems of the Russian Academy of Sciences (Moscow) on ETAP-3 --a continuation of the Meaning-Text Model approach to MT begun in the 1970s, initially for French-Russian but now for English-Russian translation of electrical engineering and computer science texts.
Another project with East European antecedents is taking place in Berlin (Gesellschaft für Multilinguale Systeme) on a Russian-German system based on the Metal platform. The Russian analysis derives form previous research at the German Academy of Sciences and the German synthesis on systems developed for Metal. The aim is initially a SunSparc system.
The application of general-purpose natural language systems to automatic translation is becoming more and more common. The large LOLITA project at Durham University is aiming to develop a problem-and domain-independent natural language engineering core for multiple applications. One of these is translation, and reports have been given of an experiment involving Italian-English translation via a conceptual representation.
An outcome of the Core Language Engine project at Cambridge has been the SLT (Spoken Language Translator) developed as a prototype speech translation between Swedish and English in the domain of air travel planning, and first demonstrated in 1993. Subsequently, the team have shown the flexibility and portability of the architecture by the relatively rapid construction of a system for French and English speech translation in the same domain. The system operates with a statistically trainable processor producing quasi-logical representations.
The best known spoken language system under development in Europe is, of course, the Verbmobil project funded by the German Ministry of Research and Technology and involving research groups in a number of German universities. The aim is to produce a prototype dialogue system for negotiations for German and Japanese business people with English as a common dialogue language. The system is based on language-independent disambiguated representations incorporating speech act (dialogue) information and involving domain knowledge databases. A major effort has concentrated on the analysis of dialogue in the chosen domain.

Language Engineering projects
Since the ending of Eurotra, research funds from the European Union have been granted on a wide range of projects within the broad field of language engineering, which includes multilingual tools of all kinds as well as translation assistance in various contexts. Practical implementation and collaboration with industrial partners is emphasised throughout, as well as the need for general-purpose and re-usable products.
It is not possible to describe all those projects which involve multilinguality and translation. Only a few are highlighted. The ALEP project has been devoted to the development of a platform to support a wide range of research and technology activities related to natural language processing, including a general-purpose formalism and rule interpreter, and a text handling system. (The most recent version is described in MTNI#14.) GRAAL was a parallel project for a re-usable grammar-writing formalism for text processing, including for computer-aided translation.
The development of lexical tools has been a major focus: GENELEX has defined a generic model for dictionary representations; DELIS is a tool to support lexicon building and management; MULTEXT is software for text corpora analysis and exploitation; and CRATER concentrates on bilingual corpus alignment.
More specifically translation oriented is the OTELO project with members including SAP (Germany), Lotus Development (Ireland), CST (Denmark) and Logos (Germany). The aim is to design a comprehensive automated translator's environment which combines at a single interface a variety of programs including MT, translation memory and other translation tools; and which will allow access from outside for new and potential users to try out MT over networks.
Some of the most recently approved projects are the following; which of them actually produce something worthwhile is yet to be seen. MABLe is to be a multilingual authoring system, guiding writers interactively to produce correspondence in a poorly known target language. MAY will provide multilingual access to yellow pages. MULTIMETEO is intended to generate weather forecasts in various languages from basic data supplied by meteorological computers. RECALL is to be a module for language learning which provides feedback translations for students. SPARKLE is a project to develop tools for syntactic analysis easily adapted to different languages and for semi-automatic lexical acquisition. SPEEDATA will provide continuous speech input for data entry in an Italian and German land registry. LINGUANET is to develop a multilingual communications system for police, based on experience with a controlled language Channel Tunnel (English and French) system. TREE will be provide multilingual access to a networked database of employment opportunities. TRADE is a project to translate social security reports in Italian, Spanish and English.
As before, there are a number of lexicon projects, nearly all multilingual (e.g. EUROWORDNET, INTERVAL), and projects to support the compilation and exploitation of corpora (e.g. PAROLE, SPEECHDAT). In the latter respect an important development is the establishment of the European Language Resources Association (ELRA) for the identification, collection, classification, validation, and exploitation of language resources (spoken and written), corpora, and linguistic models.
A number of European projects are tackling the automatic generation of natural language texts from databases. The APOLLO project is based on the CAT2 system mentioned earlier, with the aim of producing training documentation in French and English. DRAFTER is an experiment in the production of multilingual instruction documents for technical writers.

Networking MT
Europe was the location of one of the first networked MT service. This was the networking of Systran on the French Minitel system. Subsequently, other MT systems have become available over networks such as Internet: e.g. Logos, Metal and Globalink. Other efforts may be less familiar. TeleTaal is offering a PC-based word processing package with spelling and style checkers (in Dutch, French, German, Italian, and Spanish), which includes on-line support to electronic dictionaries and translation assistance through network links to the Globalink MT service. And there are experimental projects: MAITS is a EU-supported project to develop an interface to support access to MT services and translation memories, and TELELANG is investigating networked translation services (human translation as well as MT-based, terminology databases, linguistic resources, etc.
Finally, mention should be made of a service from British Telecom which produces summaries of texts in a wide range of languages and not restricted by subject. NetSumm is a statistics-based program which takes as input relatively short documents and produces gists in the form of extracted sentences. It is said to work best with newspaper articles and formal reports.

Evaluation
With the attention turning in Europe increasingly to usability of multilingual and translation systems there is inevitably much concern with valid and appropriate evaluation methods. An important vehicle is the EAGLES working group set up for establishing criteria for the evaluation and assessment of language engineering tools (which Margaret King reported on in AMTA-94). So far it has not looked at MT as such, having concentrated as yet on grammar checkers and writing aids.
Also important in this field is the TSNLP project (Essex University) which is seeking to establish test suites for natural language tools, including MT. And finally, we should remember that some of the most thorough examinations and evaluations of MT systems and translation aids have emanated from European organisations; most recently the two reports from Ovum Ltd. (London) on the global market and future prospects, and on the current translation technology available.

Sources
The sources of this survey are mainly conferences held in the last two years: particularly the MT Summit in Luxembourg in 1995, the Language Engineering Conventions in 1994(LEC 1994, the MT conference in Cranfield in 1995, and the Translating and the Computer conferences in 1995 (Aslib 1995), and the Sixth Theoretical and Methodological Issues in MT conference in Leuven, 1995(TMI 1995. Other sources are various reports in MT News International, particularly those on MT in Europe by Colin Brace (MTNI#12), Paul Hearn (MTNI#14), Dorothy Senez (MTNI#14) and Jörg Schütz (MTNI#15).