The BIASVAL
field specifier (case sensitive) allows you to bias the score of result documents by a specified percentage, based on whether they include a specific value in the specified field.
NOTE: You can only use BIASVAL
when the field is configured as:
, when the
configuration parameter is set to True
.
FieldText=BIASVAL{fieldValue,percentBoost}:fieldName
fieldValue
|
The value that the specified field must contain to increase or decrease the weight by the percentBoost . |
percentBoost
|
A percentage in the range -100 to 100. The percentage (positive or negative) by which to boost the relevance of documents that have the value When you set |
fieldName
|
The name of the field that must be present (and must contain the proper value) for the document relevance to be boosted. |
FieldText=BIASVAL{Cambridge,10}:TOWN
A document whose TOWN
field value is Cambridge
has its weighting increased by 10% (although the weighting cannot go over 100%).
FieldText=BIASVAL{Cambridge,10}:TOWN+BIASVAL{London,-10}:TOWN
A document whose TOWN
field value is Cambridge
has its weighting increased by 10%, and a document whose TOWN
field value is London
has its weighting decreased by 10%. This example shows that biases can be negative as well as positive, and that you can include more than one set of parameters with the specifier.
|