A DATABASE OF RECORDED GOOD OFFERS AND GOOD REQUESTS

This invention concerns a method for processing data recorded in a database for providing automatically transaction connections of the type between offers and requests for exchanging goods, under the control of an electronic system, or data processing system.

Various automated methods and systems for monitoring transactions between good offers and good requests have been proposed in recent years, which take advantage of the huge expansion of the Internet and information technology means that afford interactive access to information data. They are much more flexible than using conventional advertisements distributed through newspapers, catalogues or posters, and they make wider possibilities of choice available to requesters. However, they do not entirely meet the requirements that industrial conceivers are faced when dealing with such applications as those the invention is more particularly aimed at.

Known techniques make it possible to constitute and keep up to date the databases in which the goods which are the subjects of one or more transactions are recorded. Implementing an electronic data processing system makes more rigorous and more direct updating possible, in particular when eliminating advertisements which are no longer current, for whatever reason (transaction completed, withdrawal of the advertisement, etc.) or, on the other hand, when adding new advertisements or when modifying the content of the advertisements which are present in the database.

It is also known to handle a data base so as to ensure that only definite users who are authorised by the system are permitted to publish, modify and/or read advertisements, which advertisements must meet specific requirements. A process involving registration of user members is usually implemented. When this process takes place, various information can be requested from each user of the system (such as identity, postal and/or electronic or e-mail address, exact wishes or specification details), before said user is granted the status of a "member" having access to the system and can thence enter an offer or a request for a good.

However, there still exist the need for increasing the efficiency of the automatic administration of such a data base, especially with a view that the system can rapidly collect a restricted numbers of goods offered by vendors (or owners) in a list of available goods to be presented to a potential buyer as personalised transaction possibilities in correspondence to his own request for a determined good specification. It is often desired as well, reciprocally, that the system work with similar efficiency in collecting a restricted number that similarly each offering member proposing a good for sale (including the case when it is proposed free of charge) be brought in relation with a restricted list of requesting members specially collected depending on specification data associated with his personal offer.

It is therefore an object of the invention to provide a method and system whereby collections of personalised transaction possibilities are automatically determined as proposals setting forth transaction relations between offering vendor and requesting buyer. The requesting member and/or the offering member will be proposed a limited number of possibilities for transactions that has been assigned to him personally, on a free or paying basis.

It a further object of the invention to avoid the drawbacks of known techniques in database management wherein the advertisements which correspond to the characteristics which a potential buyer wishes are traditionally listed in a fixed order, with the result that the potential buyer is proposed essentially the same advertisements each time he enters the system with a definite request, with the goods appearing first to him being for instance the most recent, or the most popular, or the least expensive.

Thus, an object of the invention is to provide a system wherein rules are applied for preparing the transaction relations between owner's offers and buyer's requests so that the collection of personal relations for each user is continuously varied and the collection proposed will be different each time the user enters the system. And it is also an object of the invention that the lists collected are different from a user to another, whereas the list would be the same whoever the connected user is when performing known techniques.

In controlling automatically good owner's offers and buyer's good requests as recorded in the data base, the invention has the further object of ensuring a somehow chronological distribution of all the data in the data base by setting time dependant rules in the preparation of each current collection of goods for personal transaction relations.

In accordance with another object of the invention, there is performed an auto-adaptative process whereby a time dependant rule is applied in calculating the different goods for personalised possible transaction relations in each current collection and in varying the list therein at each instant.

In practice, the invention proposes a method comprising distinctly recording good offers by so-called owners and recording good requests by potential so-called buyers, wherein an introduction date (for the date of introduction of the good onto the market) is assigned automatically to each good when offered for transaction on the system place (the "market), and a date of accessibility is automatically assigned to each desired good as requested by each potential buyer, said accessibility date to buyer being recalculated automatically whenever a parameter involved in its calculation is modified. According to the invention, the introduction dates assigned to the various recorded goods are compared with the accessibility date to each potential buyer, and the system automatically creates a list including specific personalised offers for each good selected in correspondence with the buyer's request and of which the date of introduction onto the market is earlier than the specific accessibility date of this buyer.

The invention also proposes an architecture of electronic data processing system for implementing the method, which comprises two memory tables to record the user members and the good offers and good requests and a calculation module to receive parameters from the first and second memory tables and a market interface, and to assign to each requesting user member an accessibility date to the goods, resulting from said parameters. The calculation module is composed for updating the 10 000430

4 accessibility date of each of the users automatically when one of the input parameters is modified.

Assigning to a potential buyer an accessibility date to the goods which is caused to develop over time makes it possible to offer to a first buyer a list of accessible goods which will be different and will include more recent offers from what is offered to a second buyer whose accessibility date to the goods reflects less dynamic or more recent activity on the site. Since the list of goods is different depending on the buyer, it is understood that automatic assignment of an accessibility date also enables the electronic system to create personalised offers which are made accessible only to this potential buyer.

Automatic updating of this accessibility date by the electronic system as a function of the modifications of the parameters associated with the potential buyer ensures optimum responsiveness of the system, with automatic regulation of the offers of goods which a potential buyer can access, to make the market dynamic, while reserving the most recent advertisements for the most active and most loyal users.

According to a secondary characteristic of the invention, each personalised offer can be modified distinctly from the corresponding initial offer which is recorded in the database, so that a personalised offer can be modified by the owner of the corresponding good, without the personalised offers which the system creates for other potential buyers and the same good being modified.

Thus the invention makes it possible to set up a private relationship between the owner and a potential buyer, to whom an offer modified by the owner may be made because of his or her geographical situation, for instance.

According to preferred characteristics of the invention, the accessibility date is caiculated by the system according to whether or not the potential buyer has previously recorded an offer of a good in the database. In each case, the system assigns to the potential buyer a date which is advantageously calculated according to the equations described below. In the case that the potential buyer has offered several goods on the market, the accessibility date which is assigned to him or her is calculated according to a predetermined rule to represent a mean value which takes account of each of the goods.

According to preferred embodiments of the invention, the system assigns to a potential buyer a date of last reading, when the buyer has read at least one personalised offer which the system has created for him or her. In this case, the date of last reading is used as a supplementary condition for selection of goods to be presented to the potential buyer, and the date of introduction onto the market of these goods must be on the one hand earlier than the accessibility date to the goods, and on the other hand later than the date of last reading. The system also provides a stage of destruction of the personalised offer if the date of introduction onto the market of the corresponding good is earlier than the date of last reading assigned to the potential buyer, the destruction stage being implemented independently of the offer of a good recorded by the owner, so that said offer remains accessible to other potential buyers.

According to other characteristics of the invention, the list of goods which are accessible to each individual potential buyer is limited for each market, the electronic system keeping only a predetermined number of goods; on the other hand, the personalised offers which the system creates are ordered from the oldest good to the most recent good, and the number of these personalised offers which are created for a single good is limited.

According to characteristics of the invention, an option can be put on a good by a potential buyer, said good then being withdrawn immediately from the market. There is then an exchange of contact details between the buyer and the owner after said option is raised. The option can be cancelled by the buyer, the corresponding good then being put back onto the market with a date of introduction onto the market which the system recalculates. It can also be cancelled by the owner, the good then being withdrawn definitively from the market.

According to a characteristic of the invention, when the offer is recorded, the owner of a good supplies characteristics of the good which the owner wishes to sell, in particular the type of vehicle, the date of manufacture, the mileage, the availability date and the price. The owner also supplies the date and place of availability. The invention will now be' more fully described in the context of preferred characteristics and their advantages, referring to the figures of the attached drawings which illustrate them, and in which:

Fig. 1 shows schematically an exemplary embodiment of a database architecture according to one embodiment of the invention;

Figs. 2a, 2b, 2c illustrate the stage of comparison of values associated with a potential buyer with the parameters of the goods recorded in the database, for three types of goods each with a different distribution function, to represent the dynamics of the corresponding market (here, 3 different accessibility dates and one date of last reading are shown as examples).

In what follows, without limiting in any way the scope of the invention, one will be positioned in the framework of the application of the method to an online database, which is intended for dealing in secondhand motor vehicles. The application means a typical example for a so- called replacement market, since it is normal that the potential buyer filing a request for a vehicle has previously offered for sale in the same database a vehicle of which he was the owner. However, it will be understood that the method which will be described, and the architecture to implement it, are applicable to all types of goods which can be the subject of a transaction between a requesting buyer and an offering seller, considering that such transaction can be generally any type of exchange operation between an emitting issuer (the offering owner, or seller) and a receiving acquirer (the requesting buyer).

As shown in Fig. 1 , the database Bd includes at least two memory tables 1 and 2, in which are recorded, respectively, the characteristics of the users of the database and the characteristics of the goods which are expected to be subjects of transactions. It also includes a calculation module 7, which is adapted for receiving parameters from the memory tables 1 and 2 and returning an accessibility date to each recorded user, and a market interface 4, which is specific to each user recorded in the memory table 1 , and suitable for exchanging data with, in particular, the memory table 2. The memory table 1 stores the data of each user who is recorded in the database Bd. For a given user, the memory table 1 stores general information, entered by the user himself or herself, and associates with it first values which are calculated by the electronic system and represent the activity of the user in the database. The table 1 also delivers a parameter N _a , representing the number of potential buyers recorded in the database Bd, to the calculation module 7.

As shown in Fig. 1 , the memory table 1 includes memory blocks 3a to 3n, which are respectively associated with a given user. One memory block automatically receives updates to the first values which represent the activity of the corresponding user. These first values here are to the number of two, with an accessibility date to the goods Da and a date of last reading Db. They are received respectively in the form of an electrical signal resulting from a calculation by the calculation module 7 and in the form of an electrical signal from the market interface 4.

A user is thus differentiated from the other users in the memory table 1 by, on the one hand, general information which identifies the user, and on the other hand these two first calculated values associated with the user.

The memory table 2 stores the data of each good recorded by a user at a recording stage 12.

For a given good, the memory table 2 stores general characteristics, which are entered by the owner himself or herself at this stage 12 and describe the good. The data constitute together the offered good specification (the owner's offer specification). In addition, the system associates with these general characteristics second values which are suitable for classifying the good on the market. These second values are here the date of introduction onto the market Dj _n t _ro , which is assigned automatically, using the internal clock of the electronic system, when the good is recorded, and the class of goods to which the good belongs. For instance, in the case of motor vehicles, a class can correspond to all the people carriers which are offered for dealing in a given city. The classification of the good is determined by the system, which summarises the characteristics which the owner enters. Each good is associated with its owner, that is the user who offers it for dealing in the database. The owner thus has access in the database to the advertisements which correspond to his or her good.

The memory table 2 outputs parameters to the calculation module 7, that is a general parameter for the number of recorded goods Nb, and individual parameters for the state of reservation of each object which is offered for dealing.

As shown in Fig. 1 , the electronic system can create, on the basis of n offers recorded in the memory table 2, a copy, 6a to 6n, of each of these n offers, and supply them, at the output of the memory table 2, in the form of electrical signals created by the system, to the market interface 4. This creation of copies by the system is carried out automatically when an enquiry has been made by a potential buyer and the goods recorded in the memory table 2 correspond to this enquiry, with the comparison between the first values associated with the potential buyer and the second values associated with the goods which meets the requirements of the invention, as will be explained below. Each of these n copies is accessible in the market interface 4 only by the potential buyer, corresponding to the memory block 3a, who is at the origin of the enquiry, and by each owner 8 of the n corresponding offers.

The market interface 4 is arranged between the memory tables 1 and 2. It includes an enquiry module 10 and a read module 6. The market interface 4 is specific to each user, access to it being regulated by the system.

The enquiry module 10 receives an enquiry 1 1 from a potential buyer (buyer's request), here the user corresponding to the memory block 3a. The enquiry 1 1 which the user formulates consists of a wish for characteristics which the good must have so that the user considers making a transaction on this good. The set of such data represents the request good specification, that is the good specification associated with the buyer's request.

The enquiry module 10 adds to this enquiry 1 1 the first values associated with the potential buyer, that is the accessibility date to the goods Da and the date of last reading Db. At its output, the enquiry module 10 communicates with the memory table 2. The exchange is aimed at selecting those goods from the memory table 2 of which the characteristics have a sufficient degree of correlation with the desired characteristics in the enquiry 14 which the potential buyer has made. As will be described below, the goods are presented to the user only if the comparison of the first values associated with this user and the second values associated with the goods corresponds to the criteria of the invention. As described above, this selection ends with the creation according to the invention of n personalised offers by the system, which transforms them into the form of electrical signals from the memory table 2 to the read module 6.

The read module 6 receives said n offers. These offers can be read only by the potential buyer and their respective owner, unlike the initial offer recorded in the memory table 2, which remains accessible to everyone once the characteristics and parameters correspond.

Thus a private interface is created between a potential buyer of a good and the owner of this good, it being possible to change these private offers in the read module 6 without the initial offers being changed in the memory table 2.

Thus in this read module 6, the owner 8 of one of the goods can delete the offer 6b by a change action 13, and make it inaccessible to the potential buyer without thereby deleting definitively the offer initially recorded in the memory table 2, so that it remains accessible to other potential buyers. It will be understood that by an action 13, the owner can delete the offer 6b or change it, e.g. to change the delivery methods. According to the invention, this change will only be proposed to the potential buyer who has access to this read module 6, and not to all users.

The market interface 4 outputs an electronic signal representing the current date Di when a user connects to his or her usual market interface 4. The automatic update of the current date at each connection generates an automatic update, in the calculation module 7, of the accessibility date to the goods Da which is calculated there.

The calculation module 7 interacts with the two memory tables 1 and 2 and with the market interface 4. The calculation module 7 receives as input electrical signals representing the parameters described above, that is the number of goods Nb offered for dealing in the database and the number of potential buyers Na in this database. These parameters, which make it possible to judge the dynamics of the market and the balance of the offer and the request, are output from the memory table 2 and the memory table 1 respectively.

The calculation module 7 also receives, from the memory table 2, individual parameters representing the reservation state of each good which is present in the database Bd, with for instance the number of days during which the good remains without a buyer putting an option on it, and receives information about the current date Di from the market interface 4 when a user connects to the enquiry module 10 or read module 6.

The calculation module 7 then automatically calculates an accessibility date Da for each user. The calculation detail will be explained below, but it should be observed that this calculation takes into consideration all the data which has reached the calculation module 7, so that the calculation module 7 interacts with the memory table 1 , memory table 2 and market interface 4.

The methods of calculating the accessibility date which is assigned automatically to a potential buyer, and more generally to any user of the database, will now be described.

The data which the calculation module 7 has received over the past six months (it will be understood that this range of six months is here chosen arbitrarily, and can be changed without leaving the context of the invention) from the memory table 2 enables the module 7 to calculate, for each model of vehicle, the speed of reservation, i.e. the number of days between the date of introduction onto the market and the reservation date on which one of these models is the subject of an option to deal by a potential buyer.

The module 7 also calculates, for each model, the distribution parameters of this reservation speed, calculated as explained above. Here, the distribution of goods is considered as obeying a normal distribution law, and the calculated parameters are the expectation, the mean M and the standard deviation σ. These calculations enable the calculation module 7 to model a distribution function for each model, as shown in Figs. 2a to 2c.

Fig. 2a shows a distribution function of a model X, for which there are more offers than requests in the database (e.g. a small city car), Fig. 2b shows the same function for a common model Y, with a stable market between the offer and the request, whereas Fig. 2c shows this distribution function for a rare vehicle Z, which is very sought after and for which therefore the expectation and standard deviation are low. It will be understood that the distribution functions may be different for the same model if the system classifies the vehicles geographically. Thus city vehicles will have a different distribution function according to whether they are sold in a large conurbation or a rural environment.

These statistics are updated every day, and make it possible to control access to the market, giving a potential buyer access only to the advertisements of which the introduction dates are earlier than the accessibility dates which are assigned to them. It is therefore important for the users of the database according to the invention, who wish to access the most recent advertisements, to have assigned to them an accessibility date which is near or later than the current date, and that this accessibility date is recorded in the database by the system.

The accessibility date is calculated by the calculation module 7 according to the following equation: f Di— Dintro ,

Da = Di- (M 2a)x 1- where :

Da is the accessibility date to the goods;

and σ are the distribution parameters of the reservation speed of the good offered by the potential buyer, here the mean and standard deviation;

Di is the current date;

Dintro is the date of introduction onto the market of the good offered by the potential buyer. It should be noted here that the result of the quotient mean are

small. This means that if the previously offered vehicle is rare, an accessibility date close to the current date is assigned to the user, who potentially can have access to almost all the recorded offers. In other words, the more sought after is the vehicle which was put on the market previously, the faster its owner will have access to equally sought after vehicles. Conversely, the less sought after is the vehicle which was put on the market, the more its owner must wait before having access to very sought after vehicles.

To illustrate these remarks, three accessibility dates have been shown in Figs. 2a to 2c. One accessibility date Da1 , which is assigned to an owner of a rare good who has just recorded himself or herself and offered his or her good for sale in the database according to the invention, is represented by a continuous vertical line. An accessibility date Da2, which is assigned to a user who has just recorded himself or herself without offering a good in the database, is represented by a hatched vertical line. Finally, an accessibility date Da3, which is assigned to a user who has been registered in the database Bd for a long time, is represented by a mixed vertical line. It should be noted that in this last example, whether the user has offered a vehicle for sale previously is unspecified, to emphasise the fact that new advertisements are submitted as a priority to users who have been searching for a long time.

When a user offers several goods for dealing via the database according to the invention, an accessibility date is calculated for each vehicle, and the mean of these dates is considered to be the accessibility date for the potential buyer.

It should be noted that the above calculation is carried out for a user who wishes to acquire a good, and has previously offered another good for dealing in the database. The calculation is thus based on the value of the previously offered good, and in particular on the speed with which it becomes the subject of an option by a buyer. However, the system provides for taking into account the case of a potential buyer who has not previously put a good into the database for dealing, or who has not done so in the past six months.

In this case, the calculation module 7 assigns to such a buyer an accessibility date according to the following equation: f Na -Nb

Da = Da.m + a x (Da.m -Di) x

Nb where:

Da.m is the mean accessibility date to the goods, for buyers who have offered a good previously in the database;

Na and Nb are the number of potential buyers and the number of durable goods offered on the market;

Di is the current date;

a is the weighting coefficient, chosen around the value 1 .

The user who has not previously offered vehicles in the database benefits from a mean accessibility date. So that the accessibility date is as close as possible to the current date, the user must enter a market where the number of buyers is less than the number of offered goods. As an example, for a given offer of fifty vehicles, and if the mean accessibility date to the goods is 12 February and the current date is 12 March, an accessibility date of 5 March will be assigned to a user who positions himself or herself in a market where there are only ten requesters, whereas an accessibility date of 12 January will be assigned if the user positions himself or herself in a market where there are already a hundred requesters.

Thus the system according to the invention offers the possibility for new entrants to the system of seizing good opportunities, if these new entrants avoid the habits of the market, e.g. by choosing a type of vehicle for which there is less demand, or by choosing a standard vehicle in a geographical area where is less demand. A weighting coefficient a is chosen to reduce or not the influence of this strategic choice on the assignment of the accessibility date for new entrants. It will be understood that the accessibility date is more interesting for the user, that is near or greater than the current date, if the user meets at least one of these three characteristics: having recorded himself or herself a long time ago, having recently offered a sought after vehicle, and looking for a vehicle for which there is little demand.

The system is programmed to give an initial value of the accessibility date automatically when the program starts. Subsequently, periodically and for instance daily, the accessibility date of users who are already registered is recalculated automatically, whereas for new users, an accessibility date is assigned on the basis of a mean of the accessibility dates recorded in the database, as described above.

The use of the database for a user who is selling a motor vehicle, and who wishes to buy a second vehicle using the same database, will now be described.

In a stage 12 of recording an offer of a good, the owner identifies the vehicle by entering into the database Bd characteristics such as the type of vehicle (Type, Make, Model, Finish), the date of manufacture or of going on the road, the mileage on the current date and the number of miles driven annually. The owner also specifies the availability date and where the vehicle will be made available.

The owner also positions the offer in terms of price. The positioning in terms of price is expressed as a positive or negative percentage (e.g. -10% to -5%, etc., 0% to 5%, etc.) relative to a standard price, which the system calculates for the vehicle in question. For instance, the standard price corresponds to the price of the new vehicle, less standard depreciation based on mileage. It can also depend on the area where the market is, and on the dynamism of this local market.

The record of the vehicle in the memory table 2 is dated. This date will be considered as the introduction date Djntro of the vehicle onto the market.

To access the goods offered by other owners, the user must record himself or herself as a potential buyer, and identify the type of vehicle in which he or she is interested by entering the desired characteristics of a good to be acquired. The system invites this user to complete all the fields, i the same way as the owner had to complete them in the recording stage 12 of the offer of a good.

The user can thus complete, in one enquiry 1 1 , all the fields, or only one of them, from the type of desired vehicle, the date of manufacture or of going on the road, the mileage on the current date, the number of miles driven annually, the availability date and where the vehicle will be made available. The user may also be invited to position himself or herself in terms of price.

As described above, the enquiry module 10 takes account of this enquiry 1 1 , and exchanges output with the memory table 2. A vehicles list, which is available in the memory table 2, is then proposed in the usual read module 6 of the user who made the enquiry 1 1. According to the invention, the list of recorded goods to which the user has access on the current date depends at least on the accessibility date Da which is assigned to him or her by the calculation module 7 of the database.

So that an offer is included in the personalised list for the potential buyer, two conditions must be fulfilled. On the one hand, the buyer's desired characteristics and the characteristics of the good recorded by the owner must have a sufficient degree of correlation. On the other hand, at a stage of comparing the buyer's accessibility date to the goods with the dates of introduction of the goods corresponding to the desired characteristics, the accessibility date recorded in the system for the potential buyer must be later than the date of introduction onto the market of the vehicle concerned.

The sufficient degree of correlation is determined by the system according to initial parameters, which however can evolve according to the dynamism of the market. For instance, it may be decided initially that two of the potential buyer's desired characteristics must be the same as the corresponding characteristics recorded by the owner for the sufficient degree of correlation to be reached. With the fluctuation of the market, the system can determine that the number of offers is becoming too low in a given market, and then modify the sufficient degree of correlation so that it is reached when a single characteristic is the same. A third condition can be added, so that an offer forms part of the personalised list for the potential buyer. The date of introducing the good Dintro must be earlier than the accessibility date Da of the potential buyer, and at the same be later than the value Da.lr, which represents the accessibility date at the instant of the last reading of the market interface by this buyer :

Da.lr < Dintro < Da

As can be seen in Fig. 2b, the offers which the buyer to whom an accessibility date Da1 (continuous vertical line) and an accessibility date at the instant of the last reading Da3 (double vertical line) have been assigned can see are those which have an introduction date between Da1 and Da3 (hatched area).

The market interface 4 outputs the current date Dj to each connection of a user (Fig. 1 ), so that the accessibility date at the instant of the last reading, one of said first values associated with the user in the memory table 1 , is changed to take the value of the current date.

A filter is thus automatically implemented in the database Bd for presentation of personalised offers. If an offer of a good has already been presented to a potential buyer, and the latter connected when this offer of a good was present on his or her market interface 4, it will no longer appear on his or her interface at the next connection. The system then provides a destruction stage for personalised offers which the system has created for a potential buyer, and of which the introduction date is earlier than the accessibility date at the time of the last reading by said potential buyer. The destruction stage is implemented independently of the offer, of a good recorded by the owner, so that said offer remains accessible to other potential buyers. This makes it possible to propose new offers for each user, and favours rapid decision-making by potential buyers when they see an offer which they judge to be interesting, which makes the market more dynamic. If the market is stable, the potential buyer sees all the offers progressively. If the market is unstable and causes a change of the distribution function of the market goods, the buyer must be connected to the database in a sustained manner, so as not to miss offers.

The personalised offers are presented to the potential buyer by date of introduction onto the market, from the most recent to the oldest. The list can also be limited to a predetermined number of vehicles, e.g. ten vehicles, by keeping only the advertisements for vehicles which have been introduced to the market most recently. This predetermined number of vehicles, which can be fixed arbitrarily when the database is initialised, is then defined by the system and adjusted as a function of the dynamic of the market. For a very dynamic market for which the number of offers and/or requests reaches a predetermined threshold, the system can be programmed to reduce the number of vehicles, and conversely to increase it if the market stagnates. The list of personalised offers which is created for a potential buyer specifies, for each good, the characteristics which the owner entered at the recording stage 12 of the owner's offer, and any updates which the owner has made only on this personalised offer for the buyer, and details the specifications of the vehicle, which will enable the user to make his or her choice.

This list is available on the market interface 4 which is specific to the user who is concerned by the list, i.e. the user to whom the system assigns first values Da and Da.lr, which make this creation of personalised offers possible. Access to this market interface 4 is regulated by the system, which authorises access only by the corresponding user, and temporary access by owners of a personalised offer which is created on the interface. As was described above, the system thus proposes an area for private exchange between an owner and a buyer.

The potential buyer can put an option on one of the n offers of goods. Only one option can be put at a time. The good is then withdrawn from the market, and the system proceeds to an exchange of contact details between the potential buyer and the seller.

The option is dated, and can be cancelled by the buyer or by the seller. In the case that the option is cancelled by the buyer, the vehicle on which the option has been put is returned to the market. To avoid penalising the owner of this vehicle, the introduction date is recalculated according to the following equation: Dinti"o.n + 1 = Dintro.n 4- {Do -Di where :

Dintro.n is the introduction date of the vehicle before the option was cancelled;

Di is the current date;

D ₀ is the date on which the option is put by the potential buyer.

Also, if the potential buyer who has cancelled the option has a vehicle on the market (i.e. no option has been put on this vehicle), it remains on the market, but with a recalculated introduction date, which takes the value of the current date. Thus an unreliable user who delays for a large number of days between taking the option and cancelling it is penalised. With time, this penalty will be corrected by the length of the presence of this user in the database.

In the case that the option has been cancelled by the seller, the vehicle on which the option has been put is withdrawn from the market. It should be noted that this vehicle can be put back on the market by an initial recording stage, as described above.

If the option is not cancelled, the vehicle remains outside the market and is considered as reserved, if the date is between the option date and the availability date, or as sold if the current date is later than the availability date.

The method according to the invention and the architecture to implement it have been described with regard to the figures in the context of an application with transactions in relation to second-hand motor vehicles, but they are suitable for numerous other applications. In practice, the invention applies to any market for which the subject of a transaction is a publicly identifiable good for the users who potentially have access to the database. It can apply to very different markets such as real estate or scientific publications. In the latter case, the most recent and sought after scientific publications in a given field of expertise would be accessible as a priority to users who have themselves published their studies or who have been registered for a long time in the database. Setting parameters for the system in such a way as to adapt it as a function of the type of good and the nature of the corresponding market is also provided. Thus the number of offers of available vehicles for a potential buyer can be ten, whereas the number of available publications would be fifty, for instance.

Finally, the above parameters can be modified dynamically under the control of the electronic system, which can be programmed to follow the development of determined parameters, in particular in the database recorded in the memory tables, and which can be equipped with possibilities for learning, to function in adaptive mode.

The above description explains clearly how the invention makes it possible to achieve the objectives which have been set for it. In particular, the calculation module interacts with the memory table for users and the memory table for goods (memory tables 1 and 2) and with the market interface, and the calculation of the accessibility date as a function of the time period elapsed since the good was initially registered as being offered is made possible by this interaction. Through the assignment and recording of this accessibility date and its automatic updating by the system for each user of the database filing a good request, it is made possible to take account of the activity and loyalty of a potential buyer, and to regulate exchanges automatically. It is readily understood that calculating a number of days is just an example for calculating a time duration as the time elapsed at the current date since each good offer specification conforming to the request specification was introduced in the data base.

Nevertheless, it follows from the above that the invention is not limited to the shown exemplary embodiment of architecture, in particular in the arrangement of modules and memory tables in the database. Also, the chosen parameters for calculating the accessibility date can vary without leaving the context of the invention, and in particular the distribution function which is chosen and illustrated can be different from what is described.