When you add a term to the dictionary, you can add synonyms for that term. You can also add child terms, which can have synonyms of their own. These features increase the chance for your users to find information that is relevant to their interests.
There are two main situations in which you add synonyms. The first is when you are already adding a custom term, and that term has synonyms that should be included. For example, you might have a product or brand that is referred to by an abbreviation or acronym as well as by its full name.
Alternatively, you may want to override synonyms that already exist in the default dictionary, either because you do not want to use those default synonyms, or because you want to add synonyms that apply to your content but are not in the default dictionary:
If terms in the default dictionary have synonyms you do not want to use, you can remove them by adding the term in a custom dictionary and either giving it no synonyms at all, or only those synonyms you want to use.
It may be that terms are synonyms in your searchable content but not in the default dictionary. For example, a web site that sells antivirus software might want the verbs clean and remove to be synonymous.
When you add a known term (a term that is already in the core dictionary) to the custom dictionary, you automatically overwrite any synonyms the term might have in the core dictionary; the synonyms are not erased, but your custom entry is used instead of the core entry. Therefore, if you want to add to the existing synonyms and preserve what is already there, you must enter each of the term’s core synonyms into your custom dictionary.
An important difference between synonyms and child terms is that synonyms are two-directional; synonyms are generally expected to expand to each other. With child terms, however, the expansion is one-way. You can use propagation to specify whether the child term expands to the parent, or only to the parent term to the child.
One situation in which you might use parent and child terms instead of synonyms is a product that has multiple subtypes. For example, you might carry a brand of phone that has a variety of possible configurations, in which case the brand would be the parent term, and each of the models a child term attached to it. A search for the parent brand would return the child models, but a search for a specific model would not necessarily return the parent brand.
The example that follows shows the difference between synonym behavior and child term behavior. It assumes that you are propagating child terms to their parent. The important thing to keep in mind is that synonyms form a reciprocal relationship, whereas the parent-child relationship is one-directional.
For example: assuming you are propagating children to parents, create the following dictionary terms and synonyms:
Parent Term: Party Food
Child Term: Pizza with reciprocal synonyms Deep Dish and Thin-Crust
Child Term: Soda with reciprocal synonyms Pop and Cola
With these relationships in place, a search for any particular term also returns the synonyms:
Pizza > Deep-Dish, Thin-Crust
Deep-Dish > Pizza, Thin-Crust
Thin-Crust-> Pizza, Deep-Dish
Soda > Pop, Cola
Pop > Soda, Cola
Cola > Soda, Pop
Additionally, a search for the parent term returns the child terms and all of their synonyms:
Party Food > Pizza, Deep-Dish, Thin-Crust, Soda, Pop, Cola
Note, however, that the parent term only expands down to its children, and that Cola does not expand to Party Food or Pizza.
An alternate arrangement could involve only child terms, and no synonyms:
Parent Term: Party Food
Child Term: Pizza
Child Term: Deep-Dish
Child Term: Thin-Crust
Child Term: Soda
Child Term: Pop
Child Term: Cola
With this relationship, a search for Pizza would return only pizza, but a search for Party Food would return all of the child terms:
Party Food > Pizza, Deep-Dish, Thin-Crust, Soda, Pop, Cola
Whenever you add terms to your dictionary, think carefully about the relationships between the terms you are adding, how terms are used in your content, and how your users will phrase their queries.