Applications

Spoken Dialogue Systems (SDS) including speech recognition, speech synthesis, NLU and dialogue management started to emerge. In 1996, Charles Schwab is the first company to propose a fully automatic telephone service. It allows for up to 360 simultaneous customers to call in and get quotes on stock and options.

2.2. Generalities about Human-Machine Dialogue

Nowadays, thanks to half a century of intensive researches, interacting with

escribe

n, a dialogue will be referred to as an interaction sed on sequential turn taking. In most of the cases, rected and both agents cooperate in order to achieve

led interfaces are now surrounding us and are more or less sophisticated. Indeed, it is for example possible to activate voice dialling on your mobile phone, dictate documents to a text editing tool, open and control machines becomes amazingly common. People born during the two last decades are used to communicate with computers, answering machines, video games, etc. However, a real Human-Machine Dialogue (HMD) takes place in particular applications that will be described in the following.

Before entering into details about Spoken Dialogue Systems (SDS), it is important to have some fundamental notions about dialogue in general and

HMD in particular. This section will give some simple definitions, d

some types of dialogue applications, define different levels of communication coming up during spoken interactions, and then the general architecture of generic dialogue systems.

2.2.1. Definitions

In the rest of this dissertatio between two agents ba this interaction is goal-di

an aim. In the case of a HMD one of the agents is a human user while the other is a computer. In the particular case in which the interaction uses speech as the main communication mean, the computer implements a Spoken Dialogue System (SDS) while a system using several means of communication is referred to as a Multimodal Dialogue System (MMDS). When the HMD is dedicated to the realisation of a particular task (or set of tasks) it is called a task-oriented dialogue system. When one of the agents is an SDS, the dialogue consists of a sequence of utterances exchanged at each turn. A spoken utterance is the acoustic realisation of the intentions or concepts one of the agents wants to communicate to the other and is expressed as a word sequence.

2.2.2. Applications

Voice-enab

applications on the deskt

system to ear a summary

op of a computer, call an information providing of your e-mails or to know about the weather in a

is probably the simplest application category and was one of the first to be investigated [Bobrow et al,

ions implies that the user has to provide values for e purpose of the system is to collect

knowledge base and to provide it to the human user. Such a system should, for instance, retrieve a particular record in a database

rain ticket booking engines, automatic xamples [den Os et al, 1999].

perly) and for which collaborative dialogue will take place [Smith et al, 1992]. In this case, the

order to collect information about what is ensure that the user will perform proper particular area, your call can also be automatically routed and monitored… In general, HMD systems can be classified according to the application type they are dedicated to and to the complexity of the task.

2.2.2.1. Form Filling

The form filling applications are also referred to as frame-based, frame-driven or slot-filling applications in the literature. It

1977]. This type of applicat

a set of specific fields of a form. Th HMD

all the values.

2.2.2.2. Information Retrieval

In this case, the purpose of the system is to retrieve some specific information in a

according to its user’s will. Flight or t

book or computer retailing systems are some e

Such an application could also allow using mobile devices for accessing an information management system in a warehouse [Bagein et al, 2003]. The system could also retrieve pertinent documents about specific topics among websites [Lau et al, 1997] or provide weather forecast for a specific region [Zue et al, 2000]. Automatic call steering can also be classified in this category, as the system’s purpose is to route calls to operators able to provide the desired information [Durston et al, 2001]. All those tasks imply to collect a certain amount of relevant pieces of information about what has to be retrieved by querying the user [Bennacef et al, 1994].

2.2.2.3. Problem Solving

Troubleshooting is typically the kind of task for which the user needs his problem to be solved (getting his/her device working pro

system has to guide the user in going wrong but its role is also to

actions in order to fix the device. Consequently, the particularity of this kind of systems is that it involves not only questions and answers but also the user to perform actions and report the results. In other words, the user is a person with the ability to carry out all the required sensory and mechanical

operations to solve the problem but without sufficient knowledge while the system has adequate knowledge to solve the problem but cannot perform the required sensory and mechanical operations in order to physically solve it.

Collaboration between the user and the machine is therefore necessary.

2.2.2.4. Tutoring

Nowadays, interactive teaching and tutoring systems are becoming very attractive especially with the emergence of the e-Learning techniques [Rose et al, 1999]. In a general manner, teaching or tutoring is not only providing en if exhaustive) about a topic. A good interactive

ld detect lacks in user’s knowledge and provide

before, the re is such a system. Several

ts or chat bots, were created since the oebner Price that goes to AI systems

g to keep his hands and eyes a machine by voice or gestures. Wearable interfaces are r everyday life rather quickly enabling control of distant static information (ev

tutoring system shou

information consequently [Graesser et al, 2001]. Some systems go a step further by introducing tutoring agents providing online information about the

HMD system itself [Hakulinen et al, 2003].

2.2.2.5. Social Conversation

Some HMD systems do not have another purpose than to converse with users.

They are not considered anymore as task-oriented. As already mentioned ELIZA [Weizenbaum, 1966] softwa

‘ELIZA-like’ systems, called chat robo sixties (in the aim of winning the L

passing the Turing Test) and can be easily found on the Internet. Other works have also been conducted in order to create robots able to take part to group conversations [Matsusaka et al, 2001].

2.2.2.6. Others

Many other applications can be found to HMD systems. ‘Command and control’, for example, is one of the tasks that will probably become more popular in the next decade. An operator needin

free could command likely to enter in ou

devices [Sawhney & Schmandt, 1998]. Anyone will probably want to control TV sets, VCR or DVD players in a more natural, unified and interactive way in the close future.

2.2.3. Levels of communication in a speech-based