ATG Search includes a non-modifiable System Default Term Weights set (one per language). You can construct your own weight set by copying this default set and adding to it, by building your own weight set from scratch, or by importing a weight set.
To add a weight set:
In the Administration Options menu, go to Search Workbench > Customizations > Term Weights.
Click New Term Weight Set
Enter the name (required) and description (optional) for the weight set.
Select a language.
Click Create.
To add individual terms to the weight set, see Adding Terms to Weight Sets.