The Dynamic Selections option lets you provide guidelines that ATG Merchandising uses to determine the number of selections to display as well as the property value span used for each dynamically. So, when you select this option, you must provide the information to the following properties:
Maximum Number of Selections specifies the highest number of selections that are generated.
Minimum Faceting Property Values per Selection holds the minimum number of property values that will display in a selection. For a Price facet, for example, the facet values are the actual prices, so setting this property to 20 indicates that each selection must include products that span at least 20 prices. Keep in mind that selections divide products by the value they have for a given property. You use this property to define the minimum number of property values per selection, not products per selection.
Minimum Span of Letters/Numbers Per Selection defines, for selections that organize products alphabetically, the fewest number of letters represented in each selection. For example, setting this property to 3 permits selections to assemble in groupings no smaller than A-C, D-F, G-I, etc. Likewise, this property holds the fewest number of numbers when the faceting property holds number values.
It’s important to understand how these values are computed together to determine how selections are arranged. Consider a facet called Manufacturer that organizes products by manufacturer name. The properties are set as follows:
Maximum Number of Selections= 6
Minimum Faceting Property Values per Selection= 3
Minimum Span of Letters/Numbers per Selection= 2
Here’s an alphabetized list of manufacturers: Baddell, Bavary, Bisputal, Callap, Devonit, Dralter, Fulksome, Gacroy, Guster, Horck, Illique, Keckin, Laurate, Lemonsquash, Manfro, Pewvire, Prixsass, Quizle, Sellis, Tapple, and Zer.
In order to determine the selections to create, ATG Merchandising works through the following logic:
First, ATG Merchandising determines the first letter in the alphabet that begins a manufacturer name (B) and the corresponding last letter to begin a manufacturer name (Z) . Then, it determines the number of letters that span from one to the other (25). Note that all letters, even those such as X, that do not begin a manufacturer name, are included.
Next, ATG Merchandising begins to apply the three property values you specified systematically, beginning with the first. It divides the total number of letters (25) by the maximum letters in a range (6) to compute a possible number of letters in each selection (4).
Then, ATG Merchandising creates selections that meet these parameters and determines if they also meet the Minimum facet values per range setting (3). Note that in the selections below, the number in parentheses is the number of manufacturers represented in the selection:
B-E (6)
F-I (5)
J-M (4)
N-Q (3)
R-U (2)
V-Z (1)
Because the last two selections have fewer manufacturers than the minimum (3), ATG Merchandising runs through steps 2 and 3 again using the next greatest possible number of selections (5), and repeats this process until it produces selections that meet both the maximum number of selections and minimum number of values requirements.
Once a list of selections fits those two criteria, the third criteria, maximum span of letters in a range is applied. If ATG Merchandising can compute selections that meet all three pieces of criteria, those selections will display on the Web site as follows:
Actual Selection
Selection as It May Appear on the Site
Manufacturers in the Selection
B-I
A-I
*Baddell, Bavary, Bisputal, Callap, Devonit, Dralter, Fulksome, Gacroy, Guster, Horck, Illique (11)
J-Q
J-Q
*Keckin, Laurate, Lemonsquash, Manfro, Pewvire, Prixsass, Quizle (7)
R-Z
R-Z
*Sellis, Tapple, Zer (3)
* Products in selections won’t appear in alphabetical order unless ATG Search or Search Merchandising settings indicate they should.
Take note of the following two points. For one, even though the first manufacturer name in the alphabet begins with “B,” the selection visible on the site will include an “A.” To provide a consistent feel, all letters, even those that don’t begin a manufacturer name, are available to the site.
Although the Dynamic Selections option attempts to distribute manufacturers and letters evenly across selections, it’s unlikely for all selections to be equal on both counts.
If your faceting property is a number, a Round Selection Values to Nearest textbox works in conjunction with the Dynamic Selections option. Specifying a number to this property causes ATG Merchandising to factor this requirement into the calculations used to determine the appropriate selections just after computing the Minimum Span of Letters/Numbers per Selection requirement. Note that the Round Selection Values to Nearest property does not merely round up the values in a range used by a selection name, but is part of the logic applied when generating the selections.