Truncations
A search technique that expands a query to every word sharing its root, so searching 'run' also returns 'running', 'runner', and 'runs'.
Definition
Definition
Truncation is a query expansion technique that extends a search term to include all words sharing its root, so a search for a base form returns results containing all grammatical variants. A search for "run" also matches "runs", "running", "runner", and "ran".
This is achieved by stripping suffixes from both the query and the indexed content during processing, a technique closely related to stemming. Truncation can be applied automatically (the system always expands to root variants) or via an explicit operator (typically an asterisk: "run*" matches any word beginning with "run").
What it's used for
What it's used for
Truncation prevents zero-result pages caused by morphological variation, the user typed a verb form, a plural, or an inflected variant that the catalog happens to use in a different form.
In catalogs with technical or specialized vocabulary, truncation also reduces the synonym maintenance burden: instead of creating synonym entries for every morphological variant, a single root form covers them all.
Doofinder
Doofinder applies automatic truncation through morphological analysis during indexing.
Terms in both the catalog and user queries are reduced to their common root before matching, ensuring grammatical variants are treated as equivalent without manual configuration. The language setting of the search engine determines which morphological rules are applied.
Example
Case study
A gardening store sells "pruning shears", "pruning gloves", and "pruning saw". A user searches "prune".
Without truncation, the query would need to match "prune" literally, which doesn't appear in any product title. With truncation, "prune" and "pruning" share the same root and all three products are returned correctly.