As an alternative to having to enable the meta.stem_expand variable, which either requires the end user to add a dollar sign after each query term that they want expanded, or the admin user to add a macro that does this behind the scenes for every query term, an option to enable stemming variations of the expanded query is available.
To enable stemming variations of the expanded query, go to the Simple tab and set Enable stemming of the expanded query (query-expansion.stem-expansions) to true.
In order to only have stemming variations of the original query, you can enable query expansion and stemming of the expanded query, making sure no relation types are specified in the options (query-expansion.{automatic,manual}).
Stemming variations of original terms will be displayed in the QE display under Stemming as checked, while stemming variations of related terms will be displayed in the QE display under relation_type+stemming (e.g. Synonym+stemming, Spelling+stemming, etc.). They will appear as checked if their relation type is specified in one of the query-expansion.automatic.* options, and as unchecked if their relation type is specified in one of the query-expansion.manual.* options.
Stemming expansions are generated using the dictionary in Stemming dictionary for semantic expansions. Only one set of stemmer(s) can be applied to original terms and all relation types, which means that if you have translation expansions, you probably want to disable stemming for those.
If you only want stemming variation for certain relation types, you can control what relations have stemming variations by modifying the query expansion display module in XML.
The number of stemming variations output is controlled by the Max expansions (query-expansion.max-terms-per-type) field in the Metasearch subtab of the Advanced tab of the Project options.
To proceed to the next section click Updating Conceptual Search Settings in Your Display