Chapter 11
Dialogues
- 2 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Recommended References• Cykopath (2000). Killer Applications on the Web.
URL: http//www.cycopath.com/ 12.12.2000.
• Göker, M. H.; Thompson, C. (2000). The Adaptive Place Advisor: A
Conversational Recommendation System. In: Proc. of the 8th German
Workshop on Case-Based Reasoning, GWCBR2000, März 2000.
• Richter,M. M.,Schmitt, S.: Kundenmodellierung und Dialogführung: Eine
Herausforderung für eCRM. In: Festschrift für F. Bliemel, to appear.
• Wallner, S. (2000): Näher mein Kunde, zu Dir! In: Electronic Commerce
Magazin 4/2000. IWT Magazin Verlags-GmbH.
• M.M. Richter: Prinzipien der Künstlichen Intelligenz, §12. Teubner
Verlag.
- 3 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Sales Process and Dynamically Presented CSP’s (1)
• A customer demand presents a CSP with hard and weak constraints (see chapter 4): The solution is a product which solves the CSP in an optimal way.
• The CSP is dynamically presented: – The customer describes the demand incompletely and the supplier
has to complete it, i.e. to find out what the demand really is (collecting new constraints).
– During the sales process several decisions can be made which generate new constraints:
• The choice of a portable TV generates limits on the screen size• The choice of a laptop results in the need of a battery
- 4 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Sales Process and Dynamically Presented CSP’s (2)
• The purpose of the sales dialogue is therefore twofold:– to complete the demand – to solve the problem, i.e. to present a wanted product.
• The purpose of the dialogue is to achieve both goals by interleaving the solution for both problems.
• These goals require knowledge about customer classes which are also initially unknown. As a third goal the determination of the class arises.
• This may result in changing the demands, i.e. in changing the CSP:– Compare chapter chapter 4 for hard and weak constraints.
- 5 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Optimality Criteria (1)
• Optimality criteria for completing the demand:• Efficiency criteria:• Collect as few constraints as possible, e.g.:
– Constraints which are redundant for a solution are unnecessary
– Postpone collection of correctible constraints
• Customer treatment criteria:– Customer should be able to understand the sequence of
collecting constraints– Customers integrity should be respected
• These to types of criteria may be in conflict.
- 6 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Optimality Criteria (2)
• Optimality criteria for solving the problem:• Criteria from customer’s utility:
– The best available product satisfying the demands should be found. The key for solving this optimization problem is the similarity measure which is supposed to reflect the CSP.
– The best available product may not be sufficiently good. In this case the demand has to be analysed and possible revised. This requires to convince the customer that this is in his interest.
– The customer may not be well informed about the product and possible misunderstandings should be clarified.
– The customer may be sloppy in expressing the demand. E.g. the customer mentions Malta for the vacations but means Mediterranian.
• These examples show that the true utility of the customer may be difficult to determine.
- 7 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Optimality Criteria (3)• Criteria from suppliers utility:
– Focus on products which the supplier wants most to sell– Have the keep phase in mind: Look for long term customers– These two criteria are often in conflict!
• The interleaving problem:– The optimization problems have to be solved in one process– Consequence: The different kinds of optimization problems have
to be combined in one complex multi-criteria problem where usually only a Pareto-optimum can be expected.
• The purpose of the dialogue is to achieve this. Because we deal with knowledge intensive problems the dialogue component needs to be supported by the knowledge manager.
- 8 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Dialogue and Search Space
Search space
Search spaceafter a dialoguestep
Searchpartiallycompleted
The dialogue navigates through the search space and reduces it at the same time.
- 9 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Dialogues and Search
• The most comprehensive source of information for any customer is the internet.
• Why not using a search machine as in the internet ?
• This question cannot be answered in general.• The answer depends on the specific information
requested, on the way the information is placed and indexed in the net, and on the knowledge and experience of the customer.
• There are several differences between unsupported search in the net and knowledge based search as provided by similarity based support.
- 10 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Search Machine
Similarity
•General: Indexing the WWW•Search for Sites/Documents•Document oriented•Guess and pray principle•Search for keywords•query oriented •No specific know-how
•Application specific•Data base- / document oriented•Search for concepts/terms•Customer- & process oriented•specific know-how
Similarity and Search Machines
- 11 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
From Catalogues to Dialogues• We see an increasing scale of customer interaction:
– Catalogues– Static forms– Dynamic forms– Dialogues
• On each stage– there is more involvement of the customer– there is more understanding of the customer required– there is more knowledge on the suppliers side required– there is more flexibility required.
• In principle– also dialogues can be represented as trees– each argument which applies to dialogues also applies to the
previous stages, only in a simpler form.
- 12 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
TreesVacations in summer or winter ?
Summer Winter
Invisible ifnot applicable
The search for a product can in principle be represented in the form of a tree. Catalogues and static form are useful only for very small trees. Dynamic forms can deal with larger trees. For very largetrees a dialogue may be necessary.
- 13 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Utterances
• Dialogues consist of a sequence of utterances• Each utterance has a source and a target• In a free dialogue there are several levels of
discussing an utterance• Each level leads to an increased understanding of
the utterance• Such considerations are in particular necessary if the
source and the target language are different (e.g. german-english).
- 14 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Interlingua
SourceSource TargetTarget
SemanticsBedeutung
Syntax Syntax
Words Words
Semantics
- 15 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Choice of the Language Level
• Products can be described along two orthogonal dimensions (see chapter 9):– Descriptions of products and of functionalities– Levels of abstraction (is-a and part-of hierarchy).
• The chosen language level has to be done with respect to– description has to be understood by the customer (influenced
mainly by the customer class)– description has to be adequate for selecting a product (influenced
mainly by technical needs).
• These criteria are often in conflict with each other.This conflict has to solved at compile time.
- 16 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Preconditions for a Dialogue• If partners communicate a minimal requirement is
that they speak the same language (unless there is a translator) and at least understand the main terms.
• If technical and unfamiliar terms are involved this is in the sales process often not the case.
• It is mainly the suppliers task to take care of a language level which is accessible to both partners.
• On the other hand, this language level should be invisible to the customer who does not want to learn a new language for some few sales.
• If both partners use the same terms they still have to agree on the pragmatics and what they consider as relevant.
- 17 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Twofold Gap (1)
The supplier offers products, services etc. which really exist
The supplier has preferences what to sell
Customers desires:about productsabout functionalities about servicesetc.The customer has preferences costs/utilities
Two different worlds and views give rise to gaps:
Customer and supplier have a different terminology and intentions in their descriptions.
- 18 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Twofold Gap (2)
• The first gap:– Communication despite the different terminologies
of customer and supplier:• Find language level (mediator level) which can
be reached by both• The second gap:
– Which properties of the offered products are relevant for the preferences of the user ?
• Problem of utility and sensitivity analysis (see chapter 6)
• In order to sell a product these gaps has to be to closed
- 19 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Holiday type Activity Duration PriceNumber ofpersons
Summervacations
Florida Sport,Discos
2 Weeks
< 2000 2
8 83 5 strict strict
Technical Data
The weights reflect the utilities of the customer.
Instance:Customer preferences
Region
Supplier and customer have the same terminology
A Simple Problem: Travel Agency
- 20 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Discussion
• There are 6 attributes with symbolic or numeric domains. On each domain a local similarity function has to be defined. Strict requests have a filtering function.
• If the customer finds these attributes and their domains in some catalogue he has no problems to understand them. Additional attributes for the supplier like travel code is of no interest for the customer.
• The customer will also have no difficulty in expressing preferences using weights.
• The choice of suitable local measures may cause a difficulty because this can depend on the customer type (see chapter 10).
- 21 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
FFT of 256 Samples,0.8 million samples/sec
Clock
Data Paths Pipeline Stages
Vcc = 5V RegistersVcc = 5V
High level machine instructions
High level machine instructions
Function Product
Bridge attribute
Mediator level
Mediator Level:Electronic Switches
- 22 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Discussion (1)
• Here we observe a large terminological gap between the user (who describes the intended functionality) and the supplier (who describes technical properties of the product).
• There is only one attribute used in both descriptions (the voltage). We call such attributes bridge attributes. In this example in addition the values agree (namely 5 V).
• The usual way to define similarity measures by– first defining local measures on domains of attributes
– using the local-global principal to define the final measure
does not work here: The only common attribute is voltage!
- 23 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Discussion (2)
• In order to define a measure one needs a communication level on which the local measures can be defined. This level is called the mediator level.
• The expressions from both sides (functions, products) have to be mapped to the mediator level:– Terms
– Weights
• The terminology on the mediator level can be regarded as the introduction of virtual attributes.
• This level is not explitly visible to the customer. The virtual attributes will, however, be used in the dialogue and have therefore be understood by the customer.
- 24 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Purpose of the Dialogue• The purpose is in general twofold:
– Getting and providing information: Here the cooperative character of the dialogue dominates.
– Coming to some agreement with the partner: Here the competitive character of the dialogue plays a role
• This looks different from the customers and the suppliers side:– Each side has its own view on the information gaps– Each side has its own utilities and preferences
• This leads to a distinction between dialogue types:– Information type dialogue (also: sales talk)– Negotiation type dialogue
• Each type has again two instances, one for the customer and one for the supplier.
- 25 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Active and Passive Roles
• Each partner in the dialogue can play an active and a passive role and these roles can change. In the active as well as in the passive role partners perform actions:
• Active partners present– questions– demands – information without being asked (pro-active)
• Passive partners present– answers to questions
• Due to their different situations and utilities customers and suppliers have different instances of these roles
- 26 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Dialogues as Recursive Processes
Information or negotiation situationof the active partner
Improved informationor negotiation situationof the active partner
Process for each partner:-- Analyse the situation-- Keep or change role ?-- Select action-- Get to a new situation
Intention and knowledge of the passive partner, new situation
query, demand, information
reply
- 27 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Dialogue Strategies• Dialogues have an analogy to two persons games:
– Each partner has objectives to be satisfied. The objectives do not necessarily contradict each other, so both partners can win. The “win” is not “yes-or-no” but measured in degrees.
– Each partner can act (make moves).– A partner can perform a sequence of actions but the partners
cannot act at the same time.– After each action a new game situation is achieved.– These kinds of dialogues are cooperative.
• A strategy is mapping
{Set of situations} {Set of actions}• The strategy depends on the type of the partner and the
type of the dialogue.
- 28 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Search for... ... Products / Service ... Information ... Service / Support
Search for... ... Products / Service ... Information ... Service / Support
Presentation of...... Product Portfolio... Examples / Advantages Solutions
Customer CompanyInformation & Communication
Information Type Dialogue (1)
- 29 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Information Type Dialogue (2)
Data base for products :Product1
Product2
.
.Productn
Dialogue component
Presentationcomponent
Customer
Supplier
Search
foundproduct
Question
Answer
Productpresentation
The dialogue is not symmetric: The customer wants information about products,the supplier about demands. Only the supplier can present products.
- 30 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Information Type Dialogue: Customers View (1)
• We distinguish between customers who are– individual, “naive” partners and– commercial, “advanced” partners.
• This distinction is not identical with B2C versus B2B!
• The first group performs the dialogue as humans do and follow only a very personal,informal strategy. They will, however, appreciate a convenient dialogue and may quit it otherwise.
• Commercial partners can be supported (partially or total) by an automatic dialogue support. The main problem is the search for partners which in E-C reduces to internet search. It is especially important if there are many suppliers (see chapter 14).
- 31 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Information Type Dialogue: Customers View (2)
• Initially the customer plays the active role and approaches the supplier with some question or demand.
• Later on the customer is mostly passive:– makes information about wishes more precise,– completes information,– reacts on suggestions from the supplier.
• Role changes to active modus:– if demands are modified or replaced by others,– if demands can only partially be fulfilled or if unsatisfied and
dialogue is interrupted or closed,– if dialogue is successfully closed.
- 32 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Information Type Dialogue: Suppliers View (1)
• The supplier first has the passive role and gives a reply to the customers initiative.
• Actions to analyse the situation:– to understand customers utterances, – detecting impreciseness and incompleteness– checking if demands can be satisfied
• Change of role (from passive to active) if– customers demands are not understood, too imprecise or too
incomplete: Query to fill the information gap– product cannot be delivered as demanded: Make suggestion for
different product, suggest to deliver a part and recommend a supplier for the rest or quit.
• Later in the dialogue the supplier will be mainly active.
- 33 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Demands on Suppliers Actions and Strategy (1)
• To avoid customer’s disappointment :– the questions have to be comprehensible
– the evaluation of the sales talk should be transparent
– it should be possible to navigate freely within the acquisition process
• Don`t ask questions• which are considered as to much inquiry
• where knowledge says that the answer is
– already known or can be inferred
– not helpful for the goal
– not known by the user (this depends on the knowledge level of the user and therefore on the customer class).
- 34 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Demands on Suppliers Actions and Strategy (2)
• Questions to the customer should– be goal directed: How to reduce the search space most
(information gain aspect).
• It should be checked whether products are– Directly on stock: This is relevant if no adaptation is possible
and the product base is very large. Example: Travel details are often completed although no such travel is available any more (data base calls are too costly to be performed often).
– Available by adaptation or configuration: Here the completion has to be interleaved with the adaptation/configuration which may again cause difficulties. It can today only be realized in simple situations.
– Only partially available: Here other suppliers have to be contacted, see chapter 14.
- 35 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Demands on Suppliers Actions and Strategy (3)
• Suggestions of alternatives for products should make sense to the customer.
• The form of suppliers utterances should be considered– textual (cheap)– graphics, images, sound, video (expensive but more
effective).
• The supplier should have included in the strategy– which products to sell first– which customers to serve first– what competitors do (see chapter 14)– elements to keep the customer.
- 36 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Demands on Suppliers Actions and Strategy (4)
• The system must be easily maintainable– when products or their properties change, new customer types
are added,...
• The system must be flexible– dialogue strategies are usually not optimal and need to be
improved
• The process must be evaluable– this requires to experiment with the strategies
• Dialogue strategies should be easily transferable into the dialogue
• Customer data (histories) and results from data mining must be usable in order to increase customer satisfaction.
- 37 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Use of Knowledge in the Dialogue
• There are several knowledge types for the supplier:
– Knowledge about customers (customer classes, individual customer histories)
• preferences and utilities, interpretation of terms, how serious to take details, questions not understandable to the customer, products excluded, mentioning of constraints ...
– Knowledge about products:• properties of functionalities and products, relations between
them, availabilty, constraints, correctible constraints,...
– Knowledge about relations between them.
– The knowledge can be represented in semantic nets (see chapter 9).
- 38 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Conventional vs. VirtualSales Talk (I)
Conventional sales talk: Supplier is a human (sales assistant).– supplier tries to find out about the customer‘s requirements
provides information about appropriate products– talk can contain all elements of communication (audio, visual...)
interaction very important– supplier‘s behaviour determined by the customer‘s reactions– supplier‘s knowledge from preparatory training, personal
experiences, and logical conclusions
• But: Sales agent – may not be completely informed and/or commit errors– cannot be adapted due to different customers showing up– is only available during certain times of the day etc.
- 39 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Conventional vs. VirtualSales Talk (II)
Virtual sales talk:– supplier only represented by a software agent– sales knowledge is especially in product describing attributes– logical relationships between components, resulting
consequences, and processing strategies for the sales talk are part of supplier‘s knowledge
– customer will only continue dialogue with the software agent as long as relationships between answers and inquiries can be noticed
knowledge about customers needs to be formalized
- 40 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
The Formal Dialogue Process
• Shop-builder are responsible for defining all aspects of the virtual sales talk in a formal way.– One needs to define a model describing all aspects occurring in the
informal model, e.g.
• the strategy how to guide the customer to an adequate product
• the properties of the products and the customers
• the dependencies between components of the products
• the questions to pose to the customer
• the dependencies between the questions
• etc.
– One needs a mechanism to operationalize the model
• to bring the questioning strategy into initial state
• to select questions and ensuing questions
• to assign values to attributes
• etc.
- 41 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
What has to be Formalized ?• The general concepts and operations to be
formalized are:• Roles • Information situations• Customer classes • Analysis actions • Dialogue actions
– queries, demands, replies, interrupts, finish
• Selections (of roles, dialogue actions)• Execution and reception of actions• Strategies
- 42 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Suppliers View: Basic Concepts Formally (1)• We assume first some formal representation language with
different levels of abstraction. It can later be transferred into an interchange format as XML.
• For the expressions used – synonyms may exist;– also quasi-synonyms may exist.
• Levels of abstraction, synonyms and quasi-synonyms are used and understood by particular customer classes.
• The language used internally by the supplier is fixed.• The language used in the dialogue is chosen on the
customer class. • Part of the internal language describes the similarity where
the weights are partially determined by the customer class.
- 43 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Basic Concepts Formally (2)
• Basic concepts are:– possible products (in particular their attributes and their
domains)– possible functionalities (in particular there attributes and
their domains)– the relation product realizes a functionality (and satisfies in
particular the constraints).
• These concepts can be represented e.g. in a net where the products and functionalities are attached to the nodes. The relation realizes is represented as an edge (without labels this is a binary relation without degrees).
- 44 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Basic Concepts Formally (3)• Similarity measures between
• products and products• functionalities and functionalities• functionalities and products (degree of realization)
• They are represented as labelled edges.• Further binary relations:
– Technical product description (is-a and part-of relation): attached to edges.
– Customer related relations: partially represented in the measure and optional other attachment to the edges.
• Data bases: – Data base of available products– Data base of available functionalities– Thesaurus: Dictionary of synonyms
- 45 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Basic Concepts Formally (4)
• Customer classes:• List of classes• Properties for determination of the class from
customer’s utterances or history• List of properties of treatment in the dialogue
– interpretation of terms used (in the thesaurus)– questions to ask or to avoid– preferences
• Influence on the similarity measure (weights)
- 46 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Levels of Actions
• We consider schemata of actions organize them in type levels:– The type of actions distinguishes questions, demands, answers,
offers, replies,..(concerned mainly with general concepts)
– The subtypes distinguishes kinds of questions, offers, answers,...(sales process oriented)
– The instantiation looks for specific examples like “how many horsepowers has motor A?” (domain oriented)
• The actions are combined into pairs, e.g. answer a belongs to question q. This is important to organize a meaningful dialogue and will be formulated in rules.
• Meaningful means mainly: An answer is a statement which is not only true but an answer to the question (the logic of question and answer).
- 47 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Questions and Answers (1)
• ?- domain(attribute)• ?-specific attribute values
available• ?-product properties• ?-product has property• ?-product has functionality
• ?-which product has functionality
• ?-combination of properties
• domain(attribute)• yes, no, partial list, approximate
values, constraints• relevant properties, postponed• yes, no, degrees, constraints• yes, no, degrees, alternatives,
postponed• product, list, many, none, possible
degrees• yes, no, constraint, products
Question Answer
Assumption: Information sufficiently complete and precise
“postponed” is answered if demand is correctible
- 48 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Questions and Answers (2)
• ?-product properties• ?-product has property
• ?-product has functionality
• ?-which product has functionality
• ?-combination of properties
• Give details of property• Give details about property, or
product• Give details about properties or
functionality, name new constraints • Give details about products or
functionality • Give details about products,
properties or functionality
Information too incomplete or imprecise: Change to active role.The specific reply is generated by the analysis action.
Question Reply
- 49 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Demands and Offers
• Product named precisely
• Product with properties named• Product for intended
functionality• Demand inconsistent
(condition)
• Offer, offer of alternatives or parts, quit
• Offer, offer of alternative with similar properties or of parts, quit
• Offer, offer of products with similar functionality
• Name conflict, suggest solution
Demand Offer
Assumption: Information sufficiently complete and precise
Offering an alternative is essentially a change of the demand.If the information too incomplete or imprecise then the reply is essentially the same as for questions.
- 50 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal Situations• A situation is a vector sit with the following components
– role (active, passive)– information state :
• information on functionalities;• information on products;• inconsistencies;• terms not understood;• degree of completeness (qualitative estimate: small,
medium, high, full);• correctible demands• dialogue performed so far• last customer action (query, demand).
– customer class information
- 51 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Information State on Functionalities and Products
• List of properties on functionalities given by the customer (with relevances)
• List of interpreted properties on the mediator level• List of properties on products given by the customer or
obtained from intended functionalities with relevances• List of properties too vague or general
– the thesaurus needs entries for such terms and suggestions for questions, possibly indexed by customer class
• List of terms not understood• List of inconsistencies and correctible demands• Information sufficient for determining few products ? • Are there products as demanded ? (yes, no, similar ones)
- 52 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Customer Class Information
• Entries in class descriptions observed from utterances or known from history
• Classes with highest degree of membership• Several classes:
– Intersection class meaningful ? The smaller the class the better the actions are.
– Conflict state: Do these classes suggest contradicting actions ? (yes, no).
• Treatments suggested for customer class with highest probability (otherwise default treatment)– e.g. which kind of product presentation (e.g. pictures) is chosen.
- 53 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal Actions (1)• Choice of language level• Change of role (from passive to active)• Questions
– by customer– by supplier
• Demands (by customer)• Answers
– by customer and by supplier
• Offers and product presentation• Analyzing actions• Update information state• Actions are generally described by rules (ECA-rules, see
chapter 15). Performed actions are events.
- 54 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal Actions (2)• Actions performed by the customer are events in the view of the
supplier and can therefore occur as preconditions.• Rules for questions, demands, replies and offers:
IF question and (information complete and precise) THEN answer
IF question and (information incomplete or imprecise) THEN reply
IF demand and (information complete and precise) THEN offer
IF demand and (information incomplete or imprecise) THEN reply
• Remarks:– Reply includes change of roles– The first part of the precondition is the event, the second part the
condition– Questions, demands, are variables for events; the special instances of the
actions answer and reply are determined by the analysis and the strategy.
- 55 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal Actions (3)
• Analyzing actions are triggered by question and demands and refer to situations
• Checking consistency– Consistency checker
• Checking preciseness – Use thesaurus
• Checking completeness: Essentially the same as in any diagnostic situation– Properties from a list of specially named necessary properties– Too many similar objects
• Determining correctible demands
- 56 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Execution and Receive
• There is a difference between planning and executing an action: An executed action changes the situation and allows no backtracking.– An offending utterance cannot be withdrawn– a named property of a product will not be forgotten
• To execute an action may need further information– which modus for presentation is chosen– in which way is the query presented to the customer
• Update of dialogues have to be executed.• The receive of an action requires an update of the
situation, in particular the information state.
- 57 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
A Simple Strategy
• Suppose a situation sit is given. The simple strategy S acts as follows:
Take last customer action:
IF inconsistent THEN reply
IF answer or offer possible THEN give answer or offer IF reply necessary THEN request details or precision with respect to:
• information which is relevant to the customer• postponing correctible demands• reduce the search space as much as possible• avoidance of repetitions.
- 58 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal Description Languages
• Description language developed on basis of the meta language XML Document Type Definition (DTD)
• Four major elements in the description language– Network– Attribute– Question– QuestionNode
Define a Dialog Control Network (DCN)
- 59 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Formal RepresentationElement Network
Element Attribute
Element Question
Element QuestionNode
Entity Value
Entity Value Range
Element Dependence
Element QID
Entity Condition
Entity Action
Element QID
Entity Condition
Element QID
strategy
nameweightthemecomplexitymodetesthelp_textatt_id...
namequ_id...
qn_nametheme...
- 60 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Processing Questioning Strategies (I)
• The electronic shop needs a component for processing the sales talk with the customer
Dialog Control Component (DCC)
• Steps to take:1. Instantiate the model (DCN)
2. Process the dialog
3. Generate a query to the product retrieval system
- 61 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Processing Questioning Strategies (II)
Start
Generate DCN
Select Question
Questionfound?
Pose Question
Propagate Answer
Generate Query
End
no
yes
- 62 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Processing Questioning Strategies (III)
DCNGeneration
QuestionGeneration
QuestionSelection
DecisionRetraction
AnswerPropagation
QueryGeneration
Data Structure
Dialog Control Network
Adaptation
Linking
Generation
- 63 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Useful Static Forms
• Static forms represent degenerated dialogues• These forms can be very useful• The are easy to use and very successful• The answers can contain useful but not demanded
information• They can allow handwritten entries.• If they are represented as a dialogue, in particular
with spoken language many problems arise (although in a human communication they would be regarded as trivial dialogues)
- 64 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
- 65 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
- 66 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Sample Dialogue
• Taken from: www.cykopaths.com• This example pathway shows how a user can be
guided through the selection of a mobile phone: Who offers the most suitable contract to me ? (a rather incompletely described demand!)
• The opening question is presented as a picture which then takes the user through a series of further questions
• These questions are carefully chosen in order to– make the dialogue short and efficient– ask question which are meaningful to the customer
- 67 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
First Question
Which of the following images best describes how you will be using your phone ?This questions uses a picture !
- 68 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Following Questions
Will you use the phone mainly during business times?• Y N
• How many minutes do you expect to spend on calls per day?• 120• What is your monthly cell-phone allowance (in Euro)? • 500• Do you need to control the cost of your usage?
Y N
- 69 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Result• You are a business user with a cell-phone allowance of
€500 per month. • We are pleased to recommend Talk 100+ which we feel
will meet your needs. • To see more click here.
(It follows e.g. the offer of special numbers with low costs).
Comments:
- The first three questions complete the information for selecting the product. They are meaningful to the customer because he knows that such information is important. No answer is redundant.
- The last question is used for the form of payment and also considered as useful.
- 70 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Application: Used Cars Saleslive.tecinno.de/Projects/carsmart24com
• Demo application for technology demonstration
• Different Dialogue modes
• Free Text
• Forms
• Active Questions
- 71 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Negotiation Type of Dialogue
• Negotiations are in principle not of cooperative but of competitive character. Both sides are, however, interested in a result (i.e. in a successful termination) of the negotiation.
• One can distinguish between dialogues– which are preformatted:
• in a fixed format;• in a dynamically extensible format;
– completely free.
• The preformatted dialogue should be dynamic– only those queries should occur which need to be raised.
• The negotiation will be discussed in chapter 14.
- 72 - (c) 2000 Dr. Ralph Bergmann and Prof. Dr. Michael M. Richter, Universität Kaiserslautern
Summary
• The dialogue is between partners is between partners who both have a view on it; both change between active and passive roles.
• The successful performance of a dialogue requires– access to knowledge;– a strategy.
• In order to perform dialogues automatically all relevant elements have to be formalized– objects under consideration– actions– situations– strategy