GB2369696A - Query optimisation in product selection - Google Patents

Abstract

The web based product selection process allows for automatic query optimisation to improve the selection of a particular product from a complete set. Each product in a database has a number of associated attributes, and a reduction benefit value is determined for each attribute. The reduction benefit value is a measure of how much data reduction is provided by filtering the product list according to a particular attribute. The attribute providing the largest reduction is automatically selected and the user is prompted to select data relevant to the attribute. Random selection is possible if two attributes of the best and same opportunity for reduction. The process is repeated until a predetermined threshold.

Description

Product Selection Apparatus And Method The present invention relates to a product selection apparatus and method. Herein the word product includes non-physical products as well as physical products. A non-physical product might, for example, be a service product such as the provision of legal advice.

Modern advances in technology, particularly the Internet, have resulted in a vast increase in the amount of information potentially available to individuals especially when considered in terms of the relative ease of access to that information. This has expanded the range of products an individual has for selection between. However, the large range of products and abundant detailed information has resulted in increased difficulty in sifting through the large amount of information and large product range so as to locate the most suitable or desirable product.

Conventionally available Internet search engines are relatively inefficient and slavishly follow the users input, having no regard to whether or not the results are likely to be relevant.

Typical of the frustrations encountered is the user who wishes to locate product information concerning, for example, a model of car called a"Tiger". Searching on the word"Tiger" produces so many references to the animal called a Tiger that information relating to the model of car is unlikely to be found. Searching on the word"car"produces too many results to be useful. Searching on the expression"Tiger car", or variations thereof, may still not produce the desired results, since the information sought will probably only refer to the model name and will not use the expression"Tiger car". Also the results may still include many irrelevant results, such as those referring to cars which are used for tiger wildlife safaris or the like. An individual needs to become very expert before advance search techniques can be used to find quickly that which is required.

The above described difficulties are not mitigated to any significant extent, even in more mundane circumstances, such as using the web site of a particular department store or mail order company to select an everyday household item. Often the user is simply faced with a list of products to choose from, with little or no guidance in making a selection. A selection is based on a product type or category and is often made primarily on price. It is usually difficult to review product features, even if separate web pages are provided for each product and crosscomparing products is almost impossible. Some web sites offer a keyword search facility. The user types in words and a matching product is displayed. Here the results are often incorrect, or not optimal, due to the use of incorrect jargon. Often only one product will be identified (eg the first on the list), when there are actually a number which might be of interest (explicit or implicit) to choose between. Also the difficulty of cross-comparing still exists where more than one product is identified.

Against this background, the present invention seeks to provide a product selection apparatus and method which are easy to use, which better optimise the range of products from which a user makes a selection (not too broad and not too narrow) and which reach a final selection in an efficient manner.

Thus, according to a first aspect of the present invention there is provided an automated method of selecting a number of products from a plurality of products comprising the steps of: - providing an information source having a respective product information for each of said plurality of products, each product information comprising a plurality of attribute values each relating to a respective attribute of the product; - processing each product information so as to calculate a reduction benefit value for each attribute included in the information source wherein the reduction benefit value is a measure of the reduction in the number of products available for selection which will, on average, result if a selection is made between the attribute values in the information source for that attribute; - automatically selecting the attribute with the reduction benefit value which provides the largest reduction; - grouping the products according to their respective attribute value for the said automatically selected attribute so as to form a plurality of product groups; - presenting the product groups for user selection therebetween; - accepting the user selection of one or more product groups; - re-calculating the reduction benefit values for the remaining attributes within the user selected product group or groups; - automatically selecting a remaining attribute, from the remaining attributes within the user selected product group or groups, with the reduction benefit value which provides the largest reduction; - grouping the products from the user selected product group or groups according to their respective attribute value for the said automatically selected remaining attribute so as to form a plurality of remaining product groups; - presenting the remaining product groups for user selection therebetween; - accepting the user selection of one or more remaining product groups; and - presenting the products of the user selected remaining product group or groups for final product selection by the user.

According to a second aspect of the present invention there is provided an apparatus for selecting a number of products from a plurality of products comprising: - storage means containing an information source having a respective product information for each of said plurality of products, each product information comprising a plurality of attribute values each relating to a respective attribute of the product; - processing means for processing each product information so as to calculate a reduction benefit value for each attribute included in the information source wherein the reduction benefit value is a measure of the reduction in the number of products available for selection which will, on average, result if a selection is made between the attribute values in the information source for that attribute; - selecting means for selecting automatically the attribute with the reduction benefit value which provides the largest reduction; - grouping means for grouping the products according to their respective attribute value for the said automatically selected attribute so as to form a plurality of product groups; - means for presenting the product groups for user selection therebetween; - means for accepting the user selection of one or more product groups; - re-calculating means which re-calculate the reduction benefit values for the remaining attributes within the user selected product group or groups; - remainder selecting means for selecting automatically a remaining attribute, from the remaining attributes within the user selected product group or groups, with the reduction benefit value which provides the largest reduction; - remainder grouping means for grouping the products from the user selected product group or groups according to their respective attribute value for the said automatically selected remaining attribute so as to form a plurality of remaining product groups; - means for presenting the remaining product groups for user selection therebetween; - means for accepting the user selection of one or more remaining product groups; and - means for presenting the products of the user selected remaining product group or groups for final product selection by the user.

Embodiments of the present invention will now be described by way of further example only and with reference to the accompanying drawings, in which: Figure 1 is an example of an information source, Figure 2 illustrates an initial selection in a first example, Figure 3 illustrates a subsequent selection in the first example, Figure 4 illustrates a subsequent selection in the first example, Figure 5 illustrates a subsequent selection in the first example, Figure 6 illustrates a subsequent selection in the first example, Figure 7 illustrates a subsequent selection in the first example, Figure 8 illustrates a subsequent selection in the first example, Figure 9 illustrates a final selection in the first example, Figure 10 illustrates an initial selection in a second example, Figure 11 illustrates a subsequent selection in the second example, Figure 12 illustrates a subsequent selection in the second example, Figure 13 illustrates a subsequent selection in the second example, Figure 14 illustrates a subsequent selection in the second example, Figure 15 illustrates a subsequent selection in the second example, Figure 16 illustrates a final selection in the second example, An embodiment of the present invention will be explained with reference to an example in which a user wishes to purchase a cordless telephone. In this embodiment the invention is implemented in software which interacts with a previously established Internet web site. The embodiment carries out the relevant processing and presents the relevant questions for user selection. It does not, however, control the look and feel of the web site pages. That is the specific layout, colours and fonts etc of the web pages are not controlled by the present invention in this embodiment thereof.

The web site has access to details of a range of cordless telephones. The first stage in the method of this embodiment is the provision of an information source having a respective product information for each of a plurality of products (cordless telephones), each product information comprising a plurality of attribute values each relating to a respective attribute of the product. Figure 1 is an example of a database which acts as the information source in this embodiment. The database is a list of telephones and their respective attributes. As shown the attributes are: manufacturer, model, price, frequency (D/A), GAP, colour, number of memories, outdoor range, indoor range, talk time, digital answer. It will be noted that not all attributes have a specified value for each telephone. If no attribute value exists in the database for a particular attribute of a particular telephone then the value is considered to be null.

The next step in the method of this embodiment is the processing of each product information in the database so as to calculate a reduction benefit value for each attribute included in the database. The reduction benefit value is a measure of the reduction in the number of products available for selection which will result if a selection is made between the attribute values in the database for that attribute. The detail of this processing will be explained later.

After the reduction benefit values have been calculated, the software next makes an automatic selection of the attribute with the reduction benefit value which provides the largest reduction in the number of products available for selection. As will be explained in more detail below, in the present example the software determines that the attribute with the largest reduction benefit value is the attribute"frequency (D/A)". Thus the products are now grouped according to their respective attribute value for the attribute"frequency (D/A) ", so as to form a plurality of product groups. These product groups are then presented for user selection therebetween. Figure 2 illustrates the visual display screen as seen by the user. The product groups are"Analogue"and"Digital". As will be seen from figure 1,"Analogue"and "Digital"are the only distinct values which appear in the database for the attribute"frequency (D/A)". As an optional feature, the choice to be made (between Analogue and Digital) has also been placed in the form of a question to prompt the user as to the selection to be made. The user makes the selection, in this embodiment, by using a mouse to click a check-box for the chosen option.

Figure 2 also illustrates a further optional feature, which is the provision of an option (with an associated check-box) for"any"or"don't mind". The user would select this option if the attribute of Analogue or Digital was not important in the users selection of a cordless telephone.

It is to be noted that the first question with which the user is faced is probably not associated with what the user would consider as the most important criteria in their selection of a cordless telephone. The user may not even care whether their final product selection is an analogue or a digital phone. The first question has instead been chosen simply on the basis of which attribute presents the largest reduction in the number of products which will remain for further selection.

After clicking one of the check-boxes, in the present embodiment the user clicks a button (marked"Search"in figure 2) so as to confirm the choice made. Once the users selection of product group (Analogue or Digital) has been accepted next the software recalculates the reduction benefit values for the remaining attributes within the user selected product group or groups. Next the software automatically selects a remaining attribute, from the remaining attributes within the user selected product group, with the reduction benefit value which again provides the largest reduction in the number of products available for selection.

If the"any"or"don't mind"option is available and is selected by the user then the software simply presents the next selection without discarding any products on the basis of the attribute"frequency (D/A)". That is, the number of products to choose from has not been reduced at all by the response to the first question.

In the present example, the user has selected"Digital"in response to the first question and it is the determined that of the remaining attributes, the attribute with the highest reduction benefit value is"digital answer". That is the largest reduction in the number of telephones available for selection will now result from a choice between whether or not the telephone is equipped with a digital answer-phone facility. The corresponding display screen as seen by the user is shown in figure 3. Here it will be understood that the software has grouped the products from the user selected product group (digital cordless telephones) according to their respective attribute value ("Yes"or"No") for the automatically selected remaining attribute (digital answer) so as to form a plurality of remaining product groups (those with and those without a digital answer-phone facility). As shown in figure 3, the remaining product groups are presented for user selection therebetween. As shown, the actual attribute values ("Yes"/"No") are displayed. The remaining product groups could, of course, be equally well presented for user selection by other identifiers of the product groups, such as the labels"with answer-phone"and"without answer-phone".

A further optional feature is shown in figure 3. Specifically, when the user is presented with the choice between products with an answer-phone or not, the user is also informed that there are at that stage 16 products left to choose from.

The user makes a choice by again clicking one of the check-boxes (including the possibility of the"don't mind"option) and subsequently clicking the"search"button to confirm the choice. The users choice of remaining product group is accepted and further processing is undertaken by the software.

As shown in figure 3, the user selects telephones having an answer-phone facility.

There are at this stage 10 products left for further selection, ie 10 entries in the database for digital cordless telephones equipped with an answer-phone facility. This number is compared with a pre-set threshold. In the present example the threshold is set at 3. Since 10 is larger than the threshold, the software repeats the processing so as to present further selections to the user-until the number of products left for further selection is equal to or less than the threshold value of 3.

The remaining attribute with the largest reduction benefit value is the attribute of "number of memories". The respective remaining product groups are formed and presented for user selection. This is shown in figure 4. Here three product groups are presented to the user namely,"10","20"and"40" (as well as the"don't mind"option). These are the three distinct attribute values among the products remaining for further selection-as can be ascertained from an analysis of figure 1.

As indicated in figure 4, the user does not mind how many memories the telephone has.

As a consequence of the selection of the"don't mind"option, the software does not reduce the number of products available for selection based on the attribute of"number of memories".

That is, no products are excluded from further selection on the basis of their value for this attribute. The software simply continues the routine excluding this attribute from the further processing. Thus, the software determines the remaining attribute with the largest reduction value benefit is the attribute of"manufacturer". Again remaining product groups are formed and are presented for user selection, as indicated by figure 5.

Of course, the optional extra which advises of the number of products remaining for selection still shows (in figure 5) that there are 10 products remaining-"don't mind"having been selected in figure 4.

As shown in figure 5, there are at this stage four product groups (plus"don't mind) to be selected between. Figure 5 shows an example of the user selecting more than one product group. In this example, the user has selected products made either by BT or by Philips. Had the user selected one of the other two remaining manufactures, the final product selection (based on the entries in the database of figure 1) would then have been presented to the userthere being at this stage only one remaining product for each of the manufactures Binatone and Cable & Wireless. Nonetheless the software accepts the users selection of BT and Philips and proceeds again to select automatically the next attribute for reducing the number of products for selection-since the threshold of 3 has not yet been passed. In fact, there are now in this example 8 products left for further selection.

The software now determines that the remaining attribute with the largest reduction benefit value is the attribute of"price". This attribute is selected automatically and the remaining product groups formed and presented to the user. Figure 6 illustrates the display screen seen by the user at this stage. As indicated in figure 6, the user selects the two lower prices. This narrows the choice to 4 products, which is still more products than allowed for final user selection by the pre-set threshold value. The processing is thus repeated again.

The remaining attribute with the largest reduction benefit value at this stage is the attribute of"model". There are 4 products remaining, but two of them are the same model (distinguished between them only by the attribute"colour"). The three product groups (three model names of the remaining products) are thus presented for user selection, as shown in figure 7. The user, perhaps not being familiar with the models, selects the"don't mind" option. The processing continues as before and the remaining attribute with the largest reduction benefit value is determined at this stage to be the attribute of"colour". In fact an analysis of figure 1 will show that of the four remaining products three are coloured black and one is coloured blue. The remaining product groups"black"and"blue"are thus duly presented to the user, as indicated in figure 8. The user selects black.

With the user selection of black the number of products remaining for selection is 3, which is equal to the threshold. Consequently the previous routine is ceased and the final three products are presented to the user for final product selection. This is illustrated in figure 9, in which two of the remaining three products are displayed to the user (a scroll down operation being required to view the third product). The user can place a purchase order directly from this screen.

Figure 10 to 16 show the same example, but with the user making different selections.

Even though the first question is the same as in figure 2, the subsequent sequence of options is different. This should be readily apparent from the description given above and thus a detailed explanation of the processing sequence for figure 10 to 16 will not be given.

Calculation of the Reduction Benefit Value will now be described in detail. First, however, the general principle will be explained with reference to Table 1 set out below.

Table 1

Product Colour Size Black Small 2 White Small 3 Black Medium 4 Black Medium 5 Black Medium 6 Black Large 7 Blue Large The purpose of the Reduction Benefit Value is to provide an indication of which attribute (Colour or Size) would, if used as the basis for selection, provide the largest reduction in the number of products to select from. In Table 1, the attributes have the following values: "Colour" 5 x Black 1 x White 1 x Blue "Size" 2 x Small 3 x Medium 2 x Large From Table 1, the attribute"Size"has the largest Reduction Benefit Value. This is because the more even distribution of attribute values means that whatever choice is made, the reduction in the number of products remaining for further selection will, on average, be less than would result from an initial selection made on the basis of"Colour"-which has a more uneven distribution of values.

In the above described embodiment of the present invention, the step of processing each product information so as to calculate a reduction benefit value for each attribute includes the step of processing each product information so as to calculate a reduction benefit value for each attribute value and calculating the reduction benefit value for each attribute as the sum of the reduction benefit values for each value of that attribute divided by the number of distinct values for that attribute. Specifically, the actual formula used by the above described embodiment of the present invention is as follows : RB = Sum (RB (n))/D wherein; RB is the reduction benefit value for the attribute, RB (n) = (n/T) x ( (T-N-n)/T), T is the total (remaining) number of products, N is the number of products with a null value for the attribute, D is the number of distinct attribute values, other than null, for the attribute, and n is the number of products with a distinct, non-null, value for the attribute.

Using the example given in Table 1, the Reduction Benefit Values are as follows: Colour Values: 5xBlack, lxWhite, lxBlue

T = 7 N = 0 (since all products have a value for the attribute of Colour) D = 3 (Black, White, Blue) RB (Black) = (5/7) x ( (7-0-5)/7) = 10/49 RB (White) = (1/7) x ( (7-0-1)/7) = 6/49 RB (Blue) = (1/7) x ( (7-0-1)/7) = 6/49 RB = (10/49 + 6/49 + 6/49)/3 = 22/147 = 0.150 Size Values: 2xSmall, 3xMedium, 2xLarge

T = 7 N = 0 (since all products have a value for the attribute of Size) D = 3 (Small, Medium, Large) RB (Small) = (2/7) x ( (7-0-2)/7) = 10/49 RB (Medium) = (3/7) x ( (7-0-3)/7) = 12/49 RB (Large) = (2/7) x ( (7-0-2)/7) = 10/49 RB = (10/49 + 12/49 + 10/49) /3 = 32/147 = 0.218 Thus it can be seen that the Reduction Benefit Value for Size (0.218) is larger than the Reduction Benefit Value for Colour (0.150), indicating that an initial selection based on Size will on average more quickly reduce the number of products remaining for further selection than will an initial selection based on Colour.

Various examples and embodiments have been given above. Those examples and embodiments are not limiting of the invention, neither do they describe all of the possible variations. For example, in the database of figure 1, exact values have been given for the attribute of Price. Equally, of course, price ranges could have been specified in the databasefor example allocation one of three price ranges (eg < 50, 50 to 100, > f1O0). Also, however, the software could involve more sophisticated processing which would take the exact price values given in figure 1 and from those itself calculate various price ranges. The product groups thus formed would not be formed directly on the attribute values but on sub-sets of those values.

It is apparent that the situation could arise in which more than one attribute equally has a reduction benefit value which provides the largest reduction. This can be accommodated for simply by making a random selection between these attributes. A non-random selection can be made by, for example, choosing between these attributes on the basis of which of them first appears in the database-or a more sophisticated solution can be adopted.

A variation of the examples shown in figures 2 to 16 is to allow for more than one step of presenting for user selection to be conducted at the same time. That is several selections are displayed to the user at one time, with the presented product groups and/or presented remaining product groups being listed according to their relative reduction benefit values.

Another variation is to allow for, in a step of presenting remaining product groups to the user, also presenting the user with an option of bypassing subsequent steps in the method and proceeding to a presentation of all remaining products for final product selection by the user.

The description given above has been mainly in terms of the method steps used. The apparatus to implement the method is as follows: Apparatus for selecting a number of products from a plurality of products comprising: - storage means containing an information source having a respective product information for each of said plurality of products, each product information comprising a plurality of attribute values each relating to a respective attribute of the product; - processing means which process each product information so as to calculate a reduction benefit value for each attribute included in the information source wherein the reduction benefit value is a measure of the reduction in the number of products available for selection which will result if a selection is made between the attribute values in the information source for that attribute; - selecting means which select automatically the attribute with the reduction benefit value which provides the largest reduction; - grouping means which group the products according to their respective attribute value for the said automatically selected attribute so as to form a plurality of product groups; - means which present the product groups for user selection therebetween; - means which accept user selection of one or more product groups; - re-calculating means which re-calculate the reduction benefit values for the remaining attributes within the user selected product group or groups; - remainder selecting means which select automatically a remaining attribute, from the remaining attributes within the user selected product group or groups, with the reduction benefit value which provides the largest reduction; - remainder grouping means which group the products from the user selected product group or groups according to their respective attribute value for the said automatically selected remaining attribute so as to form a plurality of remaining product groups; - means which present the remaining product groups for user selection therebetween; - means which accept the user selection of one or more remaining product groups; and - means which present the products of the user selected remaining product group or groups for final product selection by the user.

Of course, the apparatus might comprise a processing unit which implements the said: processing means, selecting means, grouping means, re-calculating means, remainder selecting means, and remainder grouping means.

The aforegoing description has been given by way of example only and it will be appreciated by a person skilled in the art that modifications can be made without departing from the scope of the present invention.

Claims (14)

1. Claims 1. An automated method of selecting a number of products from a plurality of products comprising the steps of: - providing an information source having a respective product information for each of said plurality of products, each product information comprising a plurality of attribute values each relating to a respective attribute of the product; - processing each product information so as to calculate a reduction benefit value for each attribute included in the information source wherein the reduction benefit value is a measure of the reduction in the number of products available for selection which will, on average, result if a selection is made between the attribute values in the information source for that attribute; - automatically selecting the attribute with the reduction benefit value which provides the largest reduction; - grouping the products according to their respective attribute value for the said automatically selected attribute so as to form a plurality of product groups; - presenting the product groups for user selection therebetween; - accepting the user selection of one or more product groups; - re-calculating the reduction benefit values for the remaining attributes within the user selected product group or groups; - automatically selecting a remaining attribute, from the remaining attributes within the user selected product group or groups, with the reduction benefit value which provides the largest reduction; - grouping the products from the user selected product group or groups according to their respective attribute value for the said automatically selected remaining attribute so as to form a plurality of remaining product groups; - presenting the remaining product groups for user selection therebetween; - accepting the user selection of one or more remaining product groups; and - presenting the products of the user selected remaining product group or groups for final product selection by the user.
2. 2. A method as claimed in claim 1, wherein including, in the event of more than one attribute equally having a reduction benefit value which provides the largest reduction, the step of random selection therebetween.
3. 3. A method as claimed in claim 1 or claim 2, wherein the steps of: re-calculating the reduction benefit values for the remaining attributes within the user selected product group or groups, automatically selecting a remaining attribute, grouping so as to form a plurality of remaining product groups, presenting the remaining product groups, and accepting the user selection of one or more remaining product groups; are repeated a plurality of times, each based on the result of the previous, prior to the step of presenting products for final product selection by the user.
4. 4. A method as claimed in claim 3, further comprising the step of allocating a pre-set threshold value to the said number in the said selecting a number of products and wherein the said repeating of steps a plurality of time continues until the number of remaining product groups is less than the pre-set threshold value.
5. 5. A method as claimed in any preceding claim, wherein the step of presenting the product groups for user selection therebetween and/or one or more steps of presenting the remaining product groups for user selection therebetween includes the presentation of an"any"or"don't mind"option and wherein, in the event of selection of the"any"or"don't mind"option by the user, the subsequent step of re-calculating the reduction benefit values for the remaining attributes within the user selected product group or groups is omitted and in the subsequent step of automatically selecting a remaining attribute the plurality of remaining product groups is not reduced as a result of this user selection.
6. 6. A method as claimed in any preceding claim, wherein the steps of calculating and of recalculating a reduction benefit value for each attribute includes the step of processing each product information so as to calculate a reduction benefit value for each attribute value and calculating the reduction benefit value for each attribute as the sum of the reduction benefit values for each value of that attribute divided by the number of distinct values for that attribute.
7. 7. A method as claimed in claim 6, wherein the steps of calculating and re-calculating a reduction benefit value for each attribute comprises calculating the reduction benefit value for each attribute in accordance with the formula : - RB = Sum (RB (n))/D wherein; RB is the reduction benefit value for the attribute, RB (n) = (n/T) x ( (T-N-n)/T), T is the total (remaining) number of products, N is the number of products with a null value for the attribute, D is the number of distinct attribute values, other than null, for the attribute, and n is the number of products with a distinct, non-null, value for the attribute.
8. 8. A method as claimed in any preceding claim, wherein, at least once, more than one step of presenting for user selection is conducted at the same time with the presented product groups and/or presented remaining product groups being listed according to their relative reduction benefit values.
9. 9. A method as claimed in any preceding claim, further comprising in a step of presenting remaining product groups to the user also presenting the user with an option of bypassing subsequent steps in the method and proceeding to a presentation of all remaining products for final product selection by the user.
10. 10. A method as claimed in any preceding claim, further comprising in each step of presenting remaining product groups to the user also presenting to the user the numerical value of the number of products remaining for selection therebetween.
11. 11. Apparatus for selecting a number of products from a plurality of products comprising: - storage means containing an information source having a respective product information for each of said plurality of products, each product information comprising a plurality of attribute values each relating to a respective attribute of the product; - processing means which process each product information so as to calculate a reduction benefit value for each attribute included in the information source wherein the reduction benefit value is a measure of the reduction in the number of products available for selection which will, on average, result if a selection is made between the attribute values in the information source for that attribute; - selecting means which select automatically the attribute with the reduction benefit value which provides the largest reduction; - grouping means which group the products according to their respective attribute value for the said automatically selected attribute so as to form a plurality of product groups; - means which present the product groups for user selection therebetween; - means which accept user selection of one or more product groups; - re-calculating means which re-calculate the reduction benefit values for the remaining attributes within the user selected product group or groups; - remainder selecting means which select automatically a remaining attribute, from the remaining attributes within the user selected product group or groups, with the reduction benefit value which provides the largest reduction; - remainder grouping means which group the products from the user selected product group or groups according to their respective attribute value for the said automatically selected remaining attribute so as to form a plurality of remaining product groups; - means which present the remaining product groups for user selection therebetween; - means which accept the user selection of one or more remaining product groups; and - means which present the products of the user selected remaining product group or groups for final product selection by the user.
12. 12. Apparatus as claimed in claim 11, comprising a processing unit which implements the said: processing means, selecting means, grouping means, re-calculating the reduction benefit values for the remaining attributes within the user selected product group or groups, remainder selecting means, and remainder grouping means.
13. 13. Apparatus as claimed in claim 11 or claim 12, wherein the various said means which present and the various said means which accept include a single visual display unit.
14. 14. A data carrier having stored thereon a computer program which program when operational implements the method of any of claims 1 to 10.