The ranking options displayed when you click a Property Value Ranking link depend on the data type of the property. The following table describes the options:
Data Type | Options |
|---|---|
Numeric | You can specify that higher values are better (have higher ranking) or that lower values are better. If you select one of these options, you must also specify the minimum and maximum expected values for the property. The other option is to divide up the data into ranges and then specify a relative ranking for each range. |
Date | You can specify that earlier dates are better (have higher ranking) or that later dates are better. If you select one of these options, you must also specify the earliest and latest expected dates. The other option is to divide up the dates into ranges and then specify a relative ranking for each range. |
Text | You can specify a set of text values (e.g., |
Enumeration | An enumeration is a property with a fixed set of possible values (e.g., a “days of the week” property would have 7 possible values). You can specify a relative ranking for each value. |
Boolean | A Boolean is a property with whose value is either |
For every property value type, you have the option of specifying value ranges and number rankings that order the importance of each range relative to others. Consider the Creation Date property which uses Date data type. In order to promote new seasonal items, you might create a series of date ranges. That way, customers see the newest items created for spring before other items. Rank All Other Values last in the list, so items created at any date other than one included in the specified ranges will appear later in the list.
When you are defining ranges, the All Other Values option automatically appears at the top of a list but can be moved to any position as shown in the previous example. If you want to hide products created in the winter of 2005-2006, you might move the All Other Values to position above the range 11/01/2005 to 2/01/2006.
In these examples, rankings are unique and consecutive although they needn’t be. Giving two property values the same ranking means that for this one criterion, ATG Search sets them as equals. Keep in mind, however, that a ranking is one of several settings that determines a result’s place in the results list.
Nonconsecutive rankings work much like nonconsecutive weightings. In addition to providing a relative order, ranking provides a relative distance that determines how far apart results appear from others. Products created during November-February 2005 (with a ranking of 12) will appear significantly lower – as much as 3 times lower - in the results list than those created on a date that doesn’t fall into a specified range (with a ranking of 4). A ranking setting’s exact influence on a search result’s position may be difficult to determine because it incorporates a number of factors, such as property weightings and the order of the result list before search configuration settings are applied.
When you specify rankings, it’s important to know exactly what effect you are trying to define. For example, you would create the rankings in the prior example if you want products created in the winter of 2005-2006 to display, but to display after all others. If you don’t want such products to display at all, it’s best to use a result positioning or exclusion rule to hide them rather than specify a wide range of rankings here. Giving winter products a ranking of 100, for example, serves to eliminate the distinctions between the ranges that are ranked closely together (spring products for 2007, 2006, and 2005) rather than de-emphasize the winter products.
