Why are documents retrieved even if they contain words that are totally unrelated words to the query retrieved?
Although stemming is generally precise, sometimes words that do not share the same semantic stem (a basic related sense) are conflated. The most common errors are caused by proper names. For instance, Coveo Enterprise Search will stem visit, visits and visited into vis-, conflating them into the same semantic family. However, Visio, the name of a Microsoft product, will also be stemmed to vis- because its ending triggers stemming rules. Hence, documents containing the word Visio will be retrieved for a query that contains the word visit. In addition, a query for the word Visio will retrieve the documents that contain one or more of the following words visit, visits and visited. Proper names are more likely to be erroneously stemmed because they do not follow regular morphological rules, hence the stemming errors. Some regular words are known to be limitations of stemmers. For instance, although university and universe are not members of the semantic family, they are conflated because o
